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14,300 | Duration of hospital participation in Get With the Guidelines-Resuscitation and survival of in-hospital cardiac arrest. | Get With the Guidelines (GWTG-R) is a data registry and quality improvement program for in-hospital cardiac arrest (IHCA). It is unknown if duration of hospital participation in GWTG-R is associated with IHCA outcomes.</AbstractText>We analyzed adults with IHCA from 362 hospitals participating in GWTG-R between 2000 and 2009. Using logistic regression with generalized estimating equations to account for clustering on hospital, we determined the association between duration of hospital participation in GWTG-R and patient outcomes after IHCA, adjusted for patient and arrest characteristics and secular trend. Using these methods, we also evaluated the association between duration of participation and factors previously correlated with survival after IHCA, including ECG monitored status, after-hours arrest, and time to defibrillation.</AbstractText>Of 104,732 patients with IHCA, 17,646 patients (16.9%) survived to discharge. Duration of hospital participation in GWTG-R was associated with IHCA event survival (per year of participation, odds ratio [OR] 1.02; 95% CI 1.00-1.04; p=0.046) but not survival to discharge (OR 1.02; 95% CI 0.99-1.04; p=0.18). Among factors previously correlated with IHCA survival, duration of participation was associated with time to defibrillation ≤2 min (per year of participation, OR 1.06; 95% CI 1.03-1.10; p<0.001), but not ECG monitored status (OR 1.00; 95% CI 0.93-1.06; p=0.90) or survival of after-hours arrest (OR 1.01; 95% CI 0.99-1.03; p=0.41). Among ventricular tachycardia or ventricular fibrillation (VT/VF) arrests, time to defibrillation attenuated the association between duration of hospital participation and outcomes.</AbstractText>Duration of hospital participation in GWTG-R was significantly associated with survival of the IHCA event, but not with survival to discharge. In VT/VF arrests, this association may have been mediated by improvements in time to defibrillation.</AbstractText>Published by Elsevier Ireland Ltd.</CopyrightInformation> |
14,301 | Dynamic effects of adrenaline (epinephrine) in out-of-hospital cardiac arrest with initial pulseless electrical activity (PEA). | In cardiac arrest, pulseless electrical activity (PEA) is a challenging clinical syndrome. In a randomized study comparing intravenous (i.v.) access and drugs versus no i.v. access or drugs during advanced life support (ALS), adrenaline (epinephrine) improved return of spontaneous circulation (ROSC) in patients with PEA. Originating from this study, we investigated the time-dependent effects of adrenaline on clinical state transitions in patients with initial PEA, using a non-parametric multi-state statistical model.</AbstractText>Patients with available defibrillator recordings were included, of whom 101 received adrenaline and 73 did not. There were significantly more state transitions in the adrenaline group than in the no-adrenaline group (rate ratio = 1.6, p<0.001). Adrenaline markedly increased the rate of transition from PEA to ROSC during ALS and slowed the rate of being declared dead; e.g. by 20 min 20% of patients in the adrenaline group had been declared dead and 25% had obtained ROSC, whereas 50% in the no-adrenaline group have been declared dead and 15% had obtained ROSC. The differential effect of adrenaline could be seen after approx. 10 min of ALS for most transitions. For both groups the probability of deteriorating from PEA to asystole was highest during the first 15 min. Adrenaline increased the rate of transition from PEA to ventricular fibrillation or -tachycardia (VF/VT), and from ROSC to VF/VT.</AbstractText>Adrenaline has notable clinical effects during ALS in patients with initial PEA. The drug extends the time window for ROSC to develop, but also renders the patient more unstable. Further research should investigate the optimal dose, timing and mode of adrenaline administration during ALS.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,302 | Could successful cryoballoon ablation of paroxysmal atrial fibrillation prevent progressive left atrial remodeling? | Radiofrequency catheter ablation of atrial fibrillation (AF) has been proved to be effective and to prevent progressive left atrial (LA) remodeling. Cryoballoon catheter ablation (CCA), using a different energy source, was developed to simplify the ablation procedure. Our hypothesis was that successful CCA can also prevent progressive LA remodeling.</AbstractText>36 patients selected for their first CCA because of nonvalvular paroxysmal AF had echocardiography before and 3, 6 and 12 months after CCA. LA diameters, volumes (LAV) and LA volume index (LAVI) were evaluated. LA function was assessed by: early diastolic velocities of the mitral annulus (Aa(sept), Aa(lat)), LA filling fraction (LAFF), LA emptying fraction (LAEF) and the systolic fraction of pulmonary venous flow (PVSF). Detailed left ventricular diastolic function assessment was also performed.</AbstractText>Excluding recurrences in the first 3-month blanking period, the clinical success rate was 64%. During one-year of follow-up, recurrent atrial arrhythmia was found in 21 patients (58%). In the recurrent group at 12 months after ablation, minimal LAV (38 ± 19 to 44 ± 20 ml; p < 0.05), maximal LAV (73 ± 23 to 81 ± 24 ml; p < 0.05), LAVI (35 ± 10 to 39 ± 11 ml/m2; p = 0.01) and the maximal LA longitudinal diameter (55 ± 5 to 59 ± 6 mm; p < 0.01) had all increased. PVSF (58 ± 9 to 50 ± 10%; p = 0.01) and LAFF (36 ± 7 to 33 ± 8%; p = 0.03) had decreased. In contrast, after successful cryoballoon ablation LA size had not increased and LA function had not declined. In the recurrent group LAEF was significantly lower at baseline and at follow-up visits.</AbstractText>In patients whose paroxysmal atrial fibrillation recurred within one year after cryoballoon catheter ablation left atrial size had increased and left atrial function had declined. In contrast, successful cryoballoon catheter ablation prevented progressive left atrial remodeling.</AbstractText> |
14,303 | Extracorporeal life support for cardiogenic shock or cardiac arrest due to acute coronary syndrome. | Few data are available on the clinical outcome of patients with acute coronary syndrome (ACS) complicated by refractory cardiogenic shock or cardiac arrest who receive percutaneous extracorporeal life support (ECLS). We investigated the in-hospital outcome and predictors of mortality in these patients.</AbstractText>The investigation was a single-center, retrospective cohort study of 98 ACS patients who received ECLS to reverse hemodynamic collapse refractory to conventional treatment.</AbstractText>Circulatory status before ECLS introduction was cardiogenic shock in 34, ventricular fibrillation or pulseless ventricular tachycardia in 23, and asystole or pulseless electrical activity in 41. Ninety-four patients (95.9%) underwent emergency revascularization, including 92 who received percutaneous coronary intervention and 2 who received isolated coronary artery bypass grafting. Successful angioplasty was achieved in 65 of 92 patients (70.7%). Fifty-four patients (55.1%) were weaned from ECLS, and ECLS-related complications occurred in 35 (35.7%). All-cause in-hospital mortality rate was 67.3%, and the survival rate to hospital discharge was 32.7%. Multivariate analysis revealed that independent predictors of in-hospital mortality were unsuccessful angioplasty, asystole or pulseless electrical activity before ECLS introduction, and ECLS-related complications.</AbstractText>Despite hemodynamic support with ECLS, patients with ACS complicated by cardiogenic shock or cardiac arrest refractory to conventional treatment had high mortality. However, the higher than 30% in-hospital survival rate in this extremely critical population indicates that ECLS might improve outcomes in ACS by saving the lives of patients in this specialized category. Unsuccessful angioplasty, asystole or pulseless electrical activity before ECLS introduction, and ECLS-related complications were predictors of in-hospital mortality.</AbstractText>Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,304 | Cardiac arrest during elective orthopedic surgery due to moderate hypokalemia. | We report the case of a perioperative cardiac arrest (ventricular fibrillation) of a patient undergoing elective orthopedic surgery due to moderate hypokalemia (serum potassium 2.8 mmol/l), whereas preoperative levels were normal. He was successfully resuscitated without neurological deficits and underwent postoperative intensive care monitoring. In times of increasing populations of elderly people presenting with considerable co-morbidity, clinicians should be aware of possible rapid changes of electrolyte levels resulting in perioperative cardiac arrhythmia. |
14,305 | Hanging-associated out-of-hospital cardiac arrests in Melbourne, Australia. | Hanging is an infrequent but devastating cause of out-of-hospital cardiac arrest (OHCA). We determine the characteristics and outcomes of hanging-associated OHCA in Melbourne Australia.</AbstractText>A 10-year retrospective case review of all adult hangings (aged ≥16 years) associated with OHCA, was conducted using data from the Victorian Ambulance Cardiac Arrest Registry.</AbstractText>Between 2000 and 2009, the emergency medical service (EMS) attended 33 178 adult OHCAs of which 1321 (4%) had hanging as the aetiology. The median age (IQR) of hanging-associated OHCA cases was 39 (29-51) years and 1162 were men (88%). The first recorded rhythm by EMS was asystole seen in 1276 (75.5%) patients, pulseless electrical activity (PEA) in 38 (13.4%) cases and ventricular fibrillation in 7 cases (0.5%). EMS attempted resuscitation in 208 (15.7%) patients of whom 61 (29.3%) achieved return of spontaneous circulation (ROSC) and were transported, and 7 (3.3%) survived to hospital discharge. Hanging-associated OHCAs were younger (median (IQR) 38 (29-51) years versus 74 (61-82) years, p<0.001), less likely to have a shockable rhythm (0.5% vs 17.2%, p<0.001), receive bystander cardiopulmonary resuscitation (14.1% vs 25.5%, p<0.001) or an attempted resuscitation by EMS (15.7% vs 36.1%, p<0.001) compared with OHCA cases with an aetiology of 'presumed cardiac' arrest. Multivariable logistic regression identified factors associated with EMS decision to attempt resuscitation; the adjusted OR (95% CI) for 'presence of bystander cardiopulmonary resuscitation' was 15.8 (10.70-23.30) and for 'witnessed arrest' was 5.26 (1.17-23.30).</AbstractText>Attempted resuscitation was not always futile with a survival of 3.3%. A preventive focus is needed.</AbstractText> |
14,306 | [Acute coronary syndrome during dissection of left main as a complication of radiofrequency ablation]. | We present a case of 44 year-old female who was admitted to the hospital due to performed radio frequency ablation because of VF during WPW syndrome, which was complicated by dissection of left main. The dissection was treated with success by primary percutaneous coronary intervention with two metal stents. |
14,307 | Subcutaneous chronic implantable defibrillation systems in humans. | The recent introduction of subcutaneous implantable cardioverter defibrillator (S-ICD) has raised attention about the potential of this technology for clinical use in daily clinical practice. We review the methods and results of the four studies conducted in humans for approval of this innovative technology for daily practice. Two studies using a temporary S-ICD system (acute human studies) were conducted to search for an appropriate lead configuration and energy requirements. For this purpose, 4 S-ICD configurations were tested in 78 patients at the time of transvenous (TV)-ICD implantation. The optimal configuration was tested in 49 more patients to comparatively assess the subcutaneous defibrillation threshold (S-DFT) versus the standard TV-ICD. Long-term implants were evaluated in 55 patients using an implanted system (chronic human study). The acute humans studies led to an optimal S-ICD configuration comprising a parasternal electrode and left anterolateral thoracic pulse generator. Both configurations successfully terminated 98% of induced ventricular fibrillation (VF), but significantly higher energy levels were required with S-ICD than with TV-ICD systems (36.6 ± 19.8 J vs. 11.1 ± 8.5 J). In the chronic study, all 137 VF episodes induced at time of implant were detected with a 98% conversion rate. Two pocket infections and four lead revisions were required during 10 ± 1 months of follow-up. During this period, survival was 98%, and 12 spontaneous ventricular tachyarrhythmias were detected and treated by the device. These data show that the S-ICD systems here consistently detected and converted VF induced at time of implant as well as sustained ventricular tachyarrhythmias occurring during follow-up (248). |
14,308 | The role of calpains in myocardial remodelling and heart failure. | Calpains are cytosolic calcium-activated cysteine proteases. Recently, they have been proposed to influence signal transduction processes leading to myocardial remodelling and heart failure. In this review, we will first describe some of these molecular mechanisms. Calpains may contribute to myocardial hypertrophy and inflammation, mainly through the activation of transcription factors such as NF-κB. They play an important role in the fibrosis process partly by activating transforming growth factor β. They are also implicated in cell death as they cause the breakdown of sarcolemma and sarcomeres. Nevertheless, a key to understanding the molecular basis of calpain-mediated myocardial remodelling likely lies in the identification of mechanisms involved in calpain secretion, since cytosolic and extracellular proteases would have different functions. Finally, we will provide an overview of the available evidence that calpains are indeed actively involved in the common causes of heart failure, including hypertension, diabetes, atherosclerosis, ischaemia-reperfusion, atrial fibrillation, congestive failure, and mechanical unloading. |
14,309 | Brugada syndrome phenotype cardiac arrest in a young patient unmasked during the acute phase of amiodarone infusion: disclosure and aggravation of Brugada electrocardiographic pattern. | We report a case of an outpatient cardiac arrest due to ventricular fibrillation and resuscitated with external automated defibrillator shocks in which acute amiodarone infusion unmasked a Brugada phenotype electrocardiographic pattern. Possible interferences by this drug and suitable therapeutic actions are discussed. |
14,310 | Age and mental health predict early device-specific quality of life in patients receiving prophylactic implantable defibrillators. | Ventricular arrhythmia is a significant cause of sudden death. Implantable cardioverter-defibrillators (ICDs) offer at-risk patients a prophylactic treatment option. This prophylaxis is largely responsible for growth in utilization of ICDs. Identification of factors that may impact device-specific quality of life (QOL) is warranted. The influence of preimplant patient variables on postimplant device-specific QOL is unknown. The study aimed to determine whether preimplant psychosocial, generic health-related quality of life (HRQOL), personality disposition, or demographic factors predicted early postimplant device-specific QOL.</AbstractText>A prospective cohort study design was employed in 70 adults receiving an ICD for primary prevention. Preimplant, we measured generic HRQOL, personality disposition, depressive symptoms, age, and sex. The primary outcome was 3-month ICD device-specific QOL as measured by the Florida Patient Acceptance Scale (FPAS). We applied hierarchical multivariate regression analysis.</AbstractText>Mean age was 64.8 ± 9.4 years; 12.9% were women. Most had ischemic heart disease (77%) and a heart failure history (54.3%). Preimplant prevalence of elevated depressive symptoms was 30%. Three months post implant, the mean adjusted FPAS score was 76.8 ± 12.98. Of the variance in FPAS scores, 37% was explained by the independent variables. Younger age and poor preimplant mental HRQOL contributed most to lower FPAS scores.</AbstractText>Patient support and psychosocial interventions should target younger ICD candidates and those reporting poor preimplant mental HRQOL; these patients may be at risk for poor postimplant device-specific QOL.</AbstractText>Copyright © 2012 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,311 | Arrhythmia-related workup in hereditary myopathies. | Arrhythmias determine life expectancy in patients with hereditary myopathies.</AbstractText>The aim of this study was to summarize recent advances in the diagnosis and management of arrhythmias in hereditary myopathies.</AbstractText>Literature search via PubMed and inclusion of own experiences were performed.</AbstractText>All types of arrhythmias can be found in patients with hereditary myopathies, but some are more prevalent than others. Arrhythmias reported in myopathies include atrial fibrillation, atrial flutter, sick-sinus syndrome, preexcitation syndromes, atrioventricular conduction delay, intraventricular conduction delay, and ventricular tachycardia. Sudden cardiac death is a common finding in certain myopathies, and patients at risk for ventricular arrhythmias and sudden cardiac death should be identified early enough to implant a cardioverter-defibrillator to prevent a fatal outcome. Myopathies associated with a high risk for arrhythmias include laminopathies, Emery-Dreifuss muscular dystrophy, myotonic dystrophy I, mitochondrial myopathies, fatty-acid oxidation defects, and dystrophinopathies. To detect arrhythmias with high risk for sudden cardiac death, patients require close follow-up investigations or an implantable loop recorder. Documentation of severe arrhythmias requires immediate treatment according to established guidelines.</AbstractText>Patients with certain hereditary myopathies carry an increased risk for developing severe supraventricular or ventricular arrhythmias and for dying of sudden cardiac death. Close follow-up and long-term surveillance of the electrocardiogram may prevent fatal complications of arrhythmias in these patients.</AbstractText>Copyright © 2012 Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,312 | Coronary versus carotid blood flow and coronary perfusion pressure in a pig model of prolonged cardiac arrest treated by different modes of venoarterial ECMO and intraaortic balloon counterpulsation. | Extracorporeal membrane oxygenation (ECMO) is increasingly used in cardiac arrest (CA). Adequacy of carotid and coronary blood flows (CaBF, CoBF) and coronary perfusion pressure (CoPP) in ECMO treated CA is not well established. This study compares femoro-femoral (FF) to femoro-subclavian (FS) ECMO and intraaortic balloon counterpulsation (IABP) contribution based on CaBF, CoBF, CoPP, myocardial and brain oxygenation in experimental CA managed by ECMO.</AbstractText>In 11 female pigs (50.3 ± 3.4 kg), CA was randomly treated by FF versus FS ECMO ± IABP. Animals under general anesthesia had undergone 15 minutes of ventricular fibrillation (VF) with ECMO flow of 5 to 10 mL/kg/min simulating low-flow CA followed by continued VF with ECMO flow of 100 mL/kg/min. CaBF and CoBF were measured by a Doppler flow wire, cerebral and peripheral oxygenation by near infrared spectroscopy. CoPP, myocardial oxygen metabolism and resuscitability were determined.</AbstractText>CaBF reached values > 80% of baseline in all regimens. CoBF > 80% was reached only by the FF ECMO, 90.0% (66.1, 98.6). Addition of IABP to FF ECMO decreased CoBF to 60.7% (55.1, 86.2) of baseline, P = 0.004. FS ECMO produced 70.0% (49.1, 113.2) of baseline CoBF, significantly lower than FF, P = 0.039. Addition of IABP to FS did not change the CoBF; however, it provided significantly higher flow, 76.7% (71.9, 111.2) of baseline, compared to FF + IABP, P = 0.026. Both brain and peripheral regional oxygen saturations decreased after induction of CA to 23% (15.0, 32.3) and 34% (23.5, 34.0), respectively, and normalized after ECMO institution. For brain saturations, all regimens reached values exceeding 80% of baseline, none of the comparisons between respective treatment approaches differed significantly. After a decline to 15 mmHg (9.5, 20.8) during CA, CoPP gradually rose with time to 68 mmHg (43.3, 84.0), P = 0 .003, with best recovery on FF ECMO. Resuscitability of the animals was high, both 5 and 60 minutes return of spontaneous circulation occured in eight animals (73%).</AbstractText>In a pig model of CA, both FF and FS ECMO assure adequate brain perfusion and oxygenation. FF ECMO offers better CoBF than FS ECMO. Addition of IABP to FF ECMO worsens CoBF. FF ECMO, more than FS ECMO, increases CoPP over time.</AbstractText> |
14,313 | Randomized, double-blind pilot study of transendocardial injection of autologous aldehyde dehydrogenase-bright stem cells in patients with ischemic heart failure. | The optimal type of stem cell for use in patients with ischemic heart disease has not been determined. A primitive population of bone marrow-derived hematopoietic cells has been isolated by the presence of the enzyme aldehyde dehydrogenase and comprises a multilineage mix of stem and progenitor cells. Aldehyde dehydrogenase-bright (ALDH(br)) cells have shown promise in promoting angiogenesis and providing perfusion benefits in preclinical ischemia studies. We hypothesize that ALDH(br) cells may be beneficial in treating ischemic heart disease and thus conducted the first randomized, controlled, double-blind study to assess the safety of the transendocardial injection of autologous ALDH(br) cells isolated from the bone marrow in patients with advanced ischemic heart failure.</AbstractText>Aldehyde dehydrogenase-bright cells were isolated from patients' bone marrow on the basis of the expression of a functional (aldehyde dehydrogenase) marker. We enrolled 20 patients (treatment, n = 10; control, n = 10). Safety (primary end point) and efficacy (secondary end point) were assessed at 6 months.</AbstractText>No major adverse cardiovascular or cerebrovascular events occurred in ALDH(br)-treated patients in the periprocedural period (up to 1 month); electromechanical mapping-related ventricular tachycardia (n = 2) and fibrillation (n = 1) occurred in control patients. Aldehyde dehydrogenase-bright-treated patients showed a significant decrease in left ventricular end-systolic volume at 6 months (P = .04) and a trend toward improved maximal oxygen consumption. The single photon emission computed tomography delta analysis showed a trend toward significant improvement in reversibility in cell-treated patients (P = .053).</AbstractText>We provide preliminary evidence that treatment with the novel cell population, ALDH(br) cells, is safe and may provide perfusion and functional benefits in patients with chronic myocardial ischemia.</AbstractText>Copyright © 2012 Mosby, Inc. All rights reserved.</CopyrightInformation> |
14,314 | Therapeutic applications of octreotide in pediatric patients. | <AbstractText Label="BACKGROUND/AIM" NlmCategory="OBJECTIVE">We report our experience with the use of octreotide as primary or adjunctive therapy in children with various gastrointestinal disorders.</AbstractText>A pharmacy database identified patients who received octreotide for gastrointestinal diseases. Indications for octreotide use, dosing, effectiveness, and adverse events were evaluated by chart review.</AbstractText>A total of 21 patients (12 males), aged 1 month to 13 years, were evaluated. Eleven received octreotide for massive gastrointestinal bleeding caused by portal hypertension-induced lesions (n=7), typhlitis (1), Meckel's diverticulum (1), and indefinite source (2). Blood transfusion requirements were reduced from 23 ± 9 mL/kg (mean ± SD) to 8 ± 15 mL/kg (P<0.01). Four patients with pancreatic pseudocyst and/or ascites received octreotide over 14.0 ± 5.7 days in 2 patients. In 3 children, pancreatic pseudocyst resolved in 12 ± 2 days and pancreatic ascites resolved in 7 days in 2. Three patients with chylothorax received octreotide for 14 ± 7 days with complete resolution in each. Two infants with chronic diarrhea received octreotide over 11 ± 4.2 months. Stool output decreased from 85 ± 21 mL/kg/day to 28 ± 18 mL/kg/day, 3 months after initiation of octreotide. The child with dumping syndrome responded to octreotide in a week. Adverse events developed in 4 patients: Q-T interval prolongation and ventricular fibrillation, hyperglycemia, growth hormone deficiency, and hypertension.</AbstractText>Octreotide provides a valuable addition to the therapeutic armamentum of the pediatric gastroenterologist for a wide variety of disorders. Serious adverse events may occur and patients must be closely monitored.</AbstractText> |
14,315 | B-type natriuretic peptide predicts new-onset atrial fibrillation in patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention. | The predictive value of B-type natriuretic peptide (BNP) with respect to the occurrence of new-onset atrial fibrillation (AF) in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (PCI) is unknown. The aim of this study was to evaluate whether BNP has a predictive value for the occurrence of new-onset AF in patients with STEMI treated by primary PCI. In 180 patients with STEMI treated by primary PCI, BNP concentrations were measured 24h after chest pain onset. The Receiver Operating Characteristic analysis was performed to identify the most useful BNP cut-off level for the prediction of AF. The patients were divided into the two groups according to calculated cut-off level: high BNP group (BNP≥720 pg/mL, n=33) and low BNP group (BNP<720 pg/mL, n=147). The incidence of AF was 5.0%, and occurred more frequently in high BNP group (7/33, 21.2%) than in low BNP group (2/147, 1.4%), (p<0.001). Patients with high BNP were older (p=0.017), had more often anterior wall infarction (p=0.015), higher Killip class on admission (p=0.038), higher peak troponin I (p=0.002), lower left ventricular ejection fraction (p=0.029) than patients with low BNP. After multivariate adjustment, BNP was an independent predictor of AF (OR 3.70, 95% CI 1.40-9.77, p=0.008). BNP independently predicts the occurrence of new-onset AF in STEMI patients treated by primary PCI. |
14,316 | Acute pathophysiological influences of conducted electrical weapons in humans: A review of current literature. | Conducted electrical weapons (CEWs) deliver short high-voltage, low current energy pulses to temporarily paralyze a person by causing muscular contraction. The narrative of this article is a methodical analysis on acute pathophysiological changes within the central nervous system, cardiovascular, neuroendocrine, sympatho-adrenergic and muskuloskeletal system which can occur after application of conducted electrical weapons on human subjects. The results are based on wide-ranging literature analysis and source studies. The majority of the recent scientific publications on humans classify the health risks of an appropriate use of the CEWs device as minor. However, there still is an uncertainty about possible side-effects of these devices. Therefore medical supervision with human application is advised. |
14,317 | Feasibility, accuracy, and reproducibility of real-time full-volume 3D transthoracic echocardiography to measure LV volumes and systolic function: a fully automated endocardial contouring algorithm in sinus rhythm and atrial fibrillation. | To assess the feasibility, accuracy, and reproducibility of real-time full-volume 3-dimensional transthoracic echocardiography (3D RT-VTTE) to measure left ventricular (LV) volumes and ejection fraction (EF) using a fully automated endocardial contouring algorithm and to identify and automatically correct the contours to obtain accurate LV volumes in sinus rhythm and atrial fibrillation (AF).</AbstractText>3D transthoracic echocardiography is not used routinely to quantify LV volumes and EF. A fully automated workflow using RT-VTTE may improve clinical adoption.</AbstractText>RT-VTTE was performed and 3D EF and volumes obtained using an automated trabecular endocardial contouring algorithm; an automated correction was applied to track the compacted myocardium. Cardiac magnetic resonance (CMR) and 2-dimensional biplane Simpson method were the reference standard.</AbstractText>Ninety-one patients (67 in normal sinus rhythm [NSR], 24 in AF) were included. Among all NSR patients, there was excellent correlation between RT-VTTE and CMR for end-diastolic volume (EDV), end-systolic volume (ESV), and EF (r = 0.90, 0.96, and 0.98, respectively; p < 0.001). In patients with EF ≥50% (n = 36), EDV and ESV were underestimated by 10.7 ± 17.5 ml (p = 0.001) and by 4.1 ± 6.1 ml (p < 0.001), respectively. In those with EF <50% (n = 31), EDV and ESV were underestimated by 25.7 ± 32.7 ml (p < 0.001) and by 16.2 ± 24.0 ml (p = 0.001). Automated contour correction to track the compacted myocardium eliminated mean volume differences between RT-VTTE and CMR. In patients with AF, LV volumes and EF were accurate by RT-VTTE (r = 0.94, 0.94, and 0.91 for EDV, ESV, and EF, respectively; p < 0.001). Automated 3D LV volumes and EF were highly reproducible.</AbstractText>Rapid, accurate, and reproducible EF can be obtained by RT-VTTE in NSR and AF patients by using an automated trabecular edge contouring algorithm. Furthermore, automated contour correction to detect the compacted myocardium yields accurate and reproducible 3D LV volumes.</AbstractText>Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,318 | Simultaneous stent obstruction of triple vessels with very late stent thrombosis after implantation of sirolimus-eluting stents. | A 70-year-old man presented to the emergency department at our hospital with chest pain, 24 months after sirolimus-eluting stents (SESs) were implanted in the proximal left anterior descending coronary artery (LAD), middle right coronary artery (RCA), and middle left circumflex artery (LCX), respectively. Electrocardiogram showed complete right bundle branch block and ST-segment elevation in leads II, III, and aVF. He suddenly went to ventricular tachycardia, followed by ventricular fibrillation. Administration of electrical shock led to cardiac arrest. Immediately, we inserted a percutaneous cardiopulmonary system and intra-aortic balloon pumping. Subsequent emergent coronary angiography showed 100% thrombotic total stent obstruction of triple vessels with thrombolysis in myocardial infarction 0 flow. Thrombectomy and balloon angioplasty were performed at the in-stent thrombotic sites. Despite our intensive care, he died due to heart failure on the third day after hospitalization. |
14,319 | Influence of heart failure etiology on the effect of upgrading from right ventricular apical to biventricular or bifocal pacing in patients with permanent atrial fibrillation and advanced heart failure. | Chronic heart failure (HF) results from various disease processes. There are no data on the effect of the etiology of HF on the improvement after pacemaker upgrade. OBJECTIVES The aim of the study was to assess changes in various parameters in patients with ischemic (IC) and nonischemic (NIC) cardiomyopathy after pacemaker upgrade in pacemaker-dependent patients with permanent atrial fibrillation, in the course of advanced HF during 12-month follow-up.</AbstractText>The study involved 34 patients who underwent an upgrade from right ventricular apical to biventricular or bifocal right ventricular pacing. In each patient, 12-lead electrocardiography, transthoracic echocardiography, 6-minute walking test, and the measurement of brain natriuretic peptide levels were performed. Ischemic etiology of HF was confirmed in 25 subjects. The subgroups of cardiomyopathy were compared in terms of the improvement in relative and absolute values of the parameters at 6 and 12 months.</AbstractText>At baseline, the subgroups did not differ significantly in demographic data and the measured parameters. All patients completed the first period of follow‑up showing clinical improvement after pacemaker upgrade. A significantly greater relative increase in the left ventricular ejection fraction was observed in the NIC subgroup at 6 months. The whole 12-month follow-up period was completed by a similar percentage of the IC and NIC patients (76% vs. 88.9%; P = 0.73). In the IC subgroup, a greater degree of mitral regurgitation was observed.</AbstractText>Patients with IC or NIC who underwent an upgrade from right ventricular apical to biventricular or bifocal right ventricular pacing and completed a 12-month follow-up did not differ in clinical improvement. Significant differences were observed in echocardiographic parameters.</AbstractText> |
14,320 | Variants of the lamin A/C (LMNA) gene in non-valvular atrial fibrillation patients: a possible pathogenic role of the Thr528Met mutation. | Lamin A/C (LMNA) gene mutations cause dilated cardiomyopathy, often accompanied by conduction disturbances. Our aim was to search for LMNA mutations in individuals with atrial fibrillation.</AbstractText>A cohort of Polish subjects (N = 103) with non-valvular atrial fibrillation with a high (48.5%) prevalence of conduction system disturbances was screened for LMNA variants by direct DNA sequencing.</AbstractText>We found a single non-synonymous variant (Thr528Met) in a 72-year-old patient with normal left ventricular function and episodes of advanced atrioventricular block. One of his two mutation-carrying daughters had episodes of type I second-degree atrioventricular block on a 24-hour Holter ECG and peak exercise arrhythmia. Interpretation of cardiac anomalies observed in the other daughter was complicated by thyroid insufficiency. A Thr528Met weak pathogenic effect was supported by transient transfections of C2C12 mouse myoblasts and computationally. Another interesting variant was Ile26Ile (c.78C>T), found in a New York Heart Association class III patient with a depressed left ventricular ejection fraction (30%), left bundle branch block, and a family history of heart disease. Ile26Ile was absent in 246 healthy individuals and was computationally predicted to interfere with splicing.</AbstractText>LMNA mutations are not a frequent cause of atrial fibrillation even when conduction disease is present. Unlike the majority of LMNA mutations clearly associated with a severe clinical phenotype and a poor prognosis, Thr528Met results in a more subtle pathogenic effect, while Ile26Ile should be considered as a variant of unknown significance.</AbstractText> |
14,321 | Beneficial effects of transcatheter closure of atrial septal defects not only in young adults. | To compare cardiac events and remodeling effects after transcatheter closure of atrial septal defects (ASD) in pediatric, adult, and older adult patients.</AbstractText>A retrospective review was conducted of 353 patients who underwent transcatheter ASD closure between February 1999 and December 2007 at Siriraj Hospital. The patients were divided into 3 groups according to age: children (<18 years; n = 99); adults (18-50 years; n = 169); and older adults (>50 years; n = 85). Cardiac events at 1 year, and changes in left and right ventricular dimensions between preprocedure and 6 months and 1 year postprocedure were compared between groups.</AbstractText>Of the 353 patients, the average size of ASD was 22.1 ± 6.6 mm. Device: ASD diameter was 1.25 ± 0.28 mm. At 1 year postprocedure, the prevalence of chest discomfort and atrial fibrillation (AF) was higher in older adult patients, compared to the other age groups. Device embolization, cardiac erosion, pericardial effusion, syncope, migraine, thrombus formation, and residual shunt did not differ between groups. Within the first 6 months, the right ventricular (RV) dimension tended to dramatically decrease, while the left ventricular (LV) dimension increased in all age groups. These changes leveled off in children and in older adults, but in the adult group (18-50 years), RV shrinkage and LV expansion continued for 1 year. A low rate of early and late complications was noted.</AbstractText>Transcather closure of ASD can cause cardiac remodeling, regardless of the patient's age at the time of the procedure. For older adult patients, the long-term risk of AF continuation and chest discomfort is likely.</AbstractText>©2012, Wiley Periodicals, Inc.</CopyrightInformation> |
14,322 | Clinical experience of entirely subcutaneous implantable cardioverter-defibrillators in children and adults: cause for caution. | This paper describes our clinical experience of using an entirely subcutaneous implantable cardioverter-defibrillator (S-ICD) in children and adults. Maintaining lead integrity and long-term vascular access are critical challenges of ICD therapy, especially in younger patients. The S-ICD has considerable theoretical advantages in selected patients without pacing indications, particularly children and young adults. Although sensing in an S-ICD may be influenced by age, pathology, and posture, there are currently few published data on clinical sensing performance outside the setting of intra-operative testing or in younger patients.</AbstractText>Patients were selected by a multi-disciplinary team on clinical grounds for S-ICD implantation from a broad population at risk of sudden arrhythmic death. Sixteen patients underwent implantation [median age 20 years (range 10-48 years)]. Twelve had primary electrical disease and four had congenital structural heart disease. There were no operative complications, and ventricular fibrillation (VF) induction testing was successful in all cases. During median follow-up of 9 months (range 3-15 months), three children required re-operation. Eighteen clinical shocks were delivered in six patients. Ten shocks in four patients were inappropriate due to T-wave over-sensing. Within the eight shocks for ventricular arrhythmia, three were delivered for VF, among which two had delays in detection with time to therapy of 24 and 27 s.</AbstractText>The S-ICD is an important new option for some patients. However, these data give cause for caution in light of the limited published data regarding clinical sensing capabilities, particularly among younger patients.</AbstractText> |
14,323 | Intramural idiopathic ventricular arrhythmias originating in the intraventricular septum: mapping and ablation. | Intramural septal idiopathic ventricular arrhythmias have not been described systematically.</AbstractText>In a consecutive group of 93 patients with idiopathic ventricular arrhythmias referred for ablation, the site of origin of ventricular arrhythmias was assessed by activation mapping and pace-mapping. In 7 of 93 patients (8%), an intramural focus in the interventricular septum was identified. All ventricular arrhythmias arising intramurally had a left bundle-branch block morphology with inferior axis. The intramural focus was effectively ablated from both sides of the septum in 4 patients and from within the septum in 1 patient. The ablation procedure of an intramural focus near the His bundle failed in 2 of 7 patients. ECG and mapping characteristics of the patients with intramural septal ventricular arrhythmias differentiated intramural arrhythmias from other sites of origin.</AbstractText>Idiopathic septal ventricular arrhythmias can originate from intramural foci. Activation mapping from within a perforator branch within the interventricular septum is helpful in identifying the site of origin of intramural septal arrhythmias. Ablation within the septum or from both sites of the septum may be required to eliminate the targeted arrhythmia.</AbstractText> |
14,324 | Survival advantage from ventricular fibrillation and pulseless electrical activity in women compared to men: the Oregon Sudden Unexpected Death Study. | Studies evaluating a possible survival advantage from sudden cardiac arrest (SCA) in women have produced mixed results possibly due to a lack of comprehensive analyses. We hypothesized that race, socioeconomic status (SES), and elements of the lifetime clinical history influence gender effects and need to be incorporated within analyses of survival.</AbstractText>Cases of SCA were identified from the ongoing, prospective, multiple-source Oregon Sudden Unexpected Death Study (population approximately one million). Subjects included were age ≥18 years who underwent attempted resuscitation by EMS providers. Pearson's chi-square tests and independent samples t tests or analysis of variance were used for univariate comparisons. We evaluated gender and race differences in survival adjusted for age, circumstances of arrest, disease burden, and socioeconomic status using a logistic regression model predicting survival.</AbstractText>A total of 1,296 cases had resuscitation attempted (2002-2007; mean age 65 years, male 67%). Women were older than men (68 vs. 63 years, p < 0.0001) and were more likely to have return of spontaneous circulation (41% vs. 33%, p = 0.004). Women were more likely to present with pulseless electrical activity (PEA) and asystole (p < 0.0001), and overall, PEA was more common among African Americans (p = 0.04). Higher survival to hospital discharge was observed in women compared to men presenting with ventricular fibrillation/tachycardia (34% vs. 24%, p = 0.02) or with PEA (10% vs. 3%, p = 0.007). In a multivariate model adjusting for age, race, presenting arrhythmia, arrest circumstances, arrest location, disease burden, and SES, women were more likely than men to survive to hospital discharge [odds ratio 1.85; 95% confidence interval (1.12-3.04)].</AbstractText>Despite older age, higher prevalence of SCA in the home, and higher rates of PEA, women had a survival advantage from ventricular fibrillation and pulseless electrical activity.</AbstractText> |
14,325 | Early repolarization pattern is associated with ventricular fibrillation in patients with acute myocardial infarction. | For years early repolarization (ER) has been considered as a benign electrocardiographic finding. However, recent reports show that ER is associated with a higher incidence of ventricular fibrillation (VF) and sudden cardiac death in patients without structural heart disease. Sporadic case studies have pointed out that ER might be related to an adverse outcome in patients with stable coronary artery disease.</AbstractText>To evaluate the incidence of ER in patients with acute myocardial infarction complicated by VF.</AbstractText>The study population consisted of 60 patients (80% men; mean age 61.8 ± 13.1 years) with acute myocardial infarction. Thirty consecutive patients (80% men; mean age 63.3 ± 12 years) admitted to our hospital had documented VF during myocardial infarction and were successfully resuscitated before hospital admission. A matched control group consisted of 30 patients (80% men; mean age 60.2 ± 14.2 years) with myocardial infarction without ventricular tachyarrhythmias. Twelve-lead electrocardiograms were analyzed for ER defined as J-point elevation ≥ 0.1 mV and "notching" and "slurring" of the terminal part of the QRS complex in at least 2 lateral or inferior leads.</AbstractText>The ER pattern was observed in 18 of the 60 patients with acute myocardial infarction. Mean elevation of the J point was 0.151 ± 0.46 mV. Notching of the J wave was observed in 14 of the 18 patients and slurring in 4 of the 18 patients. ER was more common in patients with myocardial infarction complicated by VF than in patients with myocardial infarction without ventricular tachyarrhythmias (47% vs 13%; P = .005). There have been no statistical differences in the distribution of ER in the 12-lead electrocardiogram (inferior 39% vs lateral 33% vs inferolateral 28%; P >.05).</AbstractText>Early repolarization pattern seems to be associated with ventricular tachyarrhythmias in the setting of acute myocardial infarction.</AbstractText>Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,326 | In silico optimization of atrial fibrillation-selective sodium channel blocker pharmacodynamics. | Atrial fibrillation (AF) is the most common type of clinical arrhythmia. Currently available anti-AF drugs are limited by only moderate efficacy and an unfavorable safety profile. Thus, there is a recognized need for improved antiarrhythmic agents with actions that are selective for the fibrillating atrium. State-dependent Na(+)-channel blockade potentially allows for the development of drugs with maximal actions on fibrillating atrial tissue and minimal actions on ventricular tissue at resting heart rates. In this study, we applied a mathematical model of state-dependent Na(+)-channel blocking (class I antiarrhythmic drug) action, along with mathematical models of canine atrial and ventricular cardiomyocyte action potentials, AF, and ventricular proarrhythmia, to determine the relationship between their pharmacodynamic properties and atrial-selectivity, AF-selectivity (atrial Na(+)-channel block at AF rates versus ventricular block at resting rates), AF-termination effectiveness, and ventricular proarrhythmic properties. We found that drugs that target inactivated channels are AF-selective, whereas drugs that target activated channels are not. The most AF-selective drugs were associated with minimal ventricular proarrhythmic potential and terminated AF in 33% of simulations; slightly fewer AF-selective agents achieved termination rates of 100% with low ventricular proarrhythmic potential. Our results define properties associated with AF-selective actions of class-I antiarrhythmic drugs and support the idea that it may be possible to develop class I antiarrhythmic agents with optimized pharmacodynamic properties for AF treatment. |
14,327 | Isolated noncompaction of right ventricle--a case report. | Isolated noncompaction of ventricular myocardium (INVM) is a genetic cardiomyopathy due to abnormal arrest in endomyocardial embryogenesis between fetal 5th and 8th week. Noncompaction of right ventricle alone is rare. Here we present one such case where a young man presented with progressive right heart failure and atrial fibrillation. Subsequent evaluation by echo and cardiac magnetic resonance imaging confirmed our diagnosis. The cardinal manifestations of INVM are heart failure, arrhythmia, and embolic events and our case presented with former two manifestations. Echocardiographic criteria for diagnosing INVM are discussed. |
14,328 | Isolated ventricular noncompaction: implications for mechanisms of sudden cardiac death. | We present a case of a young patient, whose first manifestation of isolated ventricular noncompaction (IVNC) was sudden cardiac arrest precipitated by ventricular fibrillation. Furthermore we had the rare opportunity to record the onset of subsequent episodes of ventricular fibrillation-with discussion on the mechanisms of ventricular arrhythmias in IVNC. |
14,329 | Arrhythmia and sleep-disordered breathing in patients undergoing cardiac surgery. | Recently, the role of sleep-disordered breathing (SDB) in cardiovascular disease has attracted attention. In this study, we investigated the influence of SDB on postoperative arrhythmias after cardiac surgery.</AbstractText>In 89 patients undergoing cardiac surgery, postoperative portable monitoring for SDB and Holter electrocardiography were performed. The primary end-points were the apnea-hypopnea index (AHI) and occurrence of arrhythmia. The secondary end-points were: (1) patient background factors; (2) average heart rate; (3) maximum heart rate (total, daytime, and nighttime); (4) minimum heart rate (total, daytime, and nighttime); (5) minimum SaO(2) during sleep; and (6) an independent predictor for arrhythmia. Twenty-six patients (29.2%) had an AHI≥15 and they were classified into the SDB group, while patients with an AHI<15 formed the non-SDB group (70.8%). Although there was no significant difference in atrial fibrillation, frequent nocturnal premature ventricular contractions were significantly more common in the SDB group (19.2%) than the non-SDB group (3.2%) (p=0.01). Maximum daytime and nighttime heart rates were also significantly higher in the SDB group. AHI was a significant predictor for frequent nocturnal premature ventricular contractions.</AbstractText>This study showed that SDB is common among patients undergoing cardiac surgery, and that SDB might be closely associated with arrhythmia in these patients.</AbstractText>Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
14,330 | [Change of quality of life and NYHA class in patients with advanced heart failure and permanent atrial fibrillation after 12-months period from upgrade of pacing system]. | There is no research on the change of quality of life and NYHA classification after pacing system upgrade performed as a treatment of advanced heart failure during a long observation period in a particular population of patients with long-term apical right ventricular pacing, permanent atrial fibrillation and complete atrio-ventricular block. The aim of the study was evaluation of changes in quality of life and NYHA class in group of patients in which upgrade from right ventricular apical pacing to biventricular or bifocal right ventricular pacing was done.</AbstractText>Evaluation of quality of life was performed in a chosen group of 27 patients (20 males, mean age 71.2) who completed the 12-month observation period. Quality of life was assessed by the Short Form-36 (SF-36) questionnaire. The first examination was carried out before the planned pacing system upgrade, that is, when advanced heart failure appeared in the course of permanent atrial fibrillation and right ventricular apical pacing present for a long time (on average 7.7 years). The change of quality of life after 12-month period of upgrade pacing system was analyzed. A comparison of patient's self assessment (as far as physical aspect of quality of life is concerned - Physical Component Summary - PCS) with doctor's interview concerning NYHA classification was performed. Additionally quality of life pointed out by a patient was analyzed in relation to the diseases most common in this population: hypertension, diabetes mellitus and renal failure. Because the questionnaires were completed by the patients personally without the third party, the assessment referred to mistakes in filling in the questionnaires (quantity of missed questions and incorrect marking the answers by adding individual comments) in relation to patients' age.</AbstractText>In 12-month follow-up after pacing system upgrade, improvement of quality of life was found in 48.1% of patients. Assessment of physical aspect of quality of life was possible due to SF-36. Improvement occurred in 55.5% of patients, however in relation with NYHA classification improvement appeared in 51.8% of patients. Improvement in NYHA was in significant correlation with improvement in physical aspect of life (p = 0.025), especially in the subgroup treated by pacing system upgrade to bifocal right ventricular pacing (p = 0.0066). In the subgroup with improvement, hypertension and diabetes were less frequent, however frequency of renal failure was greater, than in the subgroup without quality of live improvement. Both before and after pacing system upgrade, there was no significant connection (only a trend) between the number of mistakes done during self-completion of the questionnaires and patients' age.</AbstractText>In 12-month follow-up after pacing system upgrade, improvement of quality of life was found in 48.1% of patients. There exists a significant correlation between the improvement of physical efficiency in NYHA class and the improvement in physical aspect of quality of life in patients' self assessment (p = 0.025). In the subgroup treated by pacing system upgrade to bifocal right ventricular pacing this correlation is especially strong (p = 0.0066).</AbstractText> |
14,331 | Evaluation of multimeric tyrosine-O-sulfate as a cytoprotectant in an in vivo model of acute myocardial infarction in pigs. | Intracoronary administration of glycosaminoglycan analogs, including the complement inhibitor dextran sulfate, attenuates myocardial ischemia/reperfusion injury (I/R injury). However, dextran sulfate has a distinct anticoagulatory effect, possibly limiting its use in specific situations in vivo. We therefore developed multimeric tyrosine sulfate (sTyr-PAA), a novel, minimally anticoagulatory, fully synthetic non-carbohydrate-containing polyacrylamide conjugate, for in vivo testing in an acute closed-chest porcine model of acute myocardial infarction.</AbstractText>Following balloon occlusion of the left anterior descending artery just after the first diagonal branch (60-minute ischemia), sTyr-PAA (approx. 10 mg/kg bodyweight, fraction with strongest complement-inhibitory and minimal anticoagulatory properties, n = 11) or phosphate-buffered saline (controls, n = 9) was administered intracoronarily into ischemic myocardium prior to 120 min of reperfusion.</AbstractText>sTyr-PAA significantly reduced infarct size (from 61.0 ± 12.0% of the ischemic area at risk to 39.4 ± 17.0%), plasma creatine kinase, local complement deposition and tissue factor upregulation, without affecting systemic coagulation. Protection was associated with significantly reduced myocardial neutrophil extravasation and translated into a significant improvement of ejection fraction and left ventricular enddiastolic pressure.</AbstractText>sTyr-PAA protected significantly against myocardial I/R injury without substantially affecting systemic coagulation. Local intravascular sTyr-PAA administration may prove advantageous in situations where bleeding complications are likely or are to be avoided at all costs.</AbstractText>Copyright © 2012 S. Karger AG, Basel.</CopyrightInformation> |
14,332 | Genetic and clinical aspects of Brugada syndrome: an update. | The Brugada Syndrome (BS) is a "channellopathy," characterized by ion (e.g., sodium, calcium, and potassium) channel dysfunction and typical ECG alterations, originally described by Osher and Wolff in 1953 and further elucidated by Josep and Pedro Brugada in 1991. BS is typically associated with a high risk for sudden cardiac death (SCD) in young and otherwise healthy adults. Although in several patients the heart is structurally normal, subtle structural abnormalities in the right ventricular outflow tract are increasingly been reported. The worldwide prevalence of this disorder is still uncertain, and there are some significant regional differences. The syndrome is characterized by a strong genetic basis, and several mutations have been identified in genes encoding subunits of cardiac sodium, potassium, and calcium channels, as well as in genes involved in the trafficking or regulation of these channels. Accordingly, eight types of BS (from BS1 to BS8) have already been described, involving mutations in SCN5A, GPD1-L, CACNA1c, CACNB2b, SCN1B, KCNE3, SCN3B, and HCN4 genes. The vast majority (i.e., up to two-third) of BS patients is asymptomatic, whereas the leading clinical manifestation is polymorphic ventricular tachycardia that can degenerate into ventricular fibrillation (VF) and SCD. The diagnosis is still challenging, and ECG abnormalities represent one component of the diagnostic criteria which also include clinical and demographic data. Although molecular genetic testing is effective in detecting mutations in 20-38% of BS patients, it represents an appealing option for stratifying the risk of adverse events as well as for prenatal testing. |
14,333 | Catecholaminergic polymorphic ventricular tachycardia in a patient with recurrent exertional syncope. | A 16-year-old male with a prior history of recurrent syncope was referred to our hospital after being resuscitated from cardiac arrest developed while playing volleyball. His electrocardiogram (ECG) demonstrated ventricular fibrillation at a local emergency department. After referral, an ECG showed bidirectional ventricular tachycardia (VT) and nonsustained Torsade de Pointes. Two days later, his heart rate became regular, and no additional episodes of VT were observed. His ECG showed sinus rhythm with a corrected QT interval of 423 msec, and two-dimensional echocardiography was unremarkable. We made the diagnosis of a catecholaminergic polymorphic VT. However, only premature ventricular complex bigeminy was induced on exercise ECG and epinephrine infusion tests, and the patient showed no episodes of syncope. His father and mother had different missense mutations in the cardiac ryanodine receptor on genetic testing. The proband had both mutations in different alleles and was symptomatic. It was recommended that the patient avoid competitive physical activities, and a β-blocker was prescribed. |
14,334 | Cardiac resynchronization therapy in patients with permanent atrial fibrillation. Is it mandatory to ablate the atrioventricular junction to obtain a good response?<Pagination><StartPage>635</StartPage><EndPage>641</EndPage><MedlinePgn>635-41</MedlinePgn></Pagination><ELocationID EIdType="doi" ValidYN="Y">10.1093/eurjhf/hfs024</ELocationID><Abstract><AbstractText Label="AIM" NlmCategory="OBJECTIVE">Current guidelines recommend atrioventricular junction (AVJ) ablation in patients with atrial fibrillation (AF) treated with cardiac resynchronization therapy (CRT). Our study compared the CRT response of patients in sinus rhythm (SR) vs. AF.</AbstractText><AbstractText Label="METHODS AND RESULTS" NlmCategory="RESULTS">In this observational, prospective, multicentre study, patients were grouped by intrinsic rhythm. For the first 2 months, the negative chronotropic drug was optimized in the AF group. If ventricular pacing was ≤85%, AVJ ablation was recommended. Responders were defined as patients who survived without requiring heart transplant and had a ≥ 10% reduction in left ventricular end-systolic volume (LVESV) at 12 months after implantation. Of 202 patients included, 156 (77%) were in SR and 46 (23%) had AF. After drug optimization, only 13/46 (28%) of the AF patients required AVJ ablation (AF + AVJ). The percentage of responders was 83/156 (53%) for SR vs. 22/46 (48%) AF (P = 0.4). Among AF patients the response was 16/33 (48%) for AF with non-AVJ ablation vs. 6/13 (46%) AF + AVJ, P = 0.56. The LVESV decreased in all three groups: -30 ± 39 mL, -24 ± 43 mL, and -22 ± 36 mL, respectively (P = 0.75). Mortality was higher in patients with AF compared with SR: 10/46 (21%) vs. 9/156 (5.7%), log rank 10.6, P <0.05.</AbstractText><AbstractText Label="CONCLUSION" NlmCategory="CONCLUSIONS">Although only 28% of the patients in AF had the AVJ ablated, there were no differences in the percentage of response and echo improvement between patients in SR and AF. However, mortality was higher in patients with AF compared with patients in SR.</AbstractText></Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Tolosana</LastName><ForeName>José María</ForeName><Initials>JM</Initials><AffiliationInfo><Affiliation>Cardiology Department-Thorax Institute. Hospital Clínic, Universitat de Barcelona, 08036 Barcelona, Catalonia, Spain.</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Arnau</LastName><ForeName>Ana Martín</ForeName><Initials>AM</Initials></Author><Author ValidYN="Y"><LastName>Madrid</LastName><ForeName>Antonio Hernández</ForeName><Initials>AH</Initials></Author><Author ValidYN="Y"><LastName>Macias</LastName><ForeName>Alfonso</ForeName><Initials>A</Initials></Author><Author ValidYN="Y"><LastName>Lozano</LastName><ForeName>Ignacio Fernández</ForeName><Initials>IF</Initials></Author><Author ValidYN="Y"><LastName>Osca</LastName><ForeName>Joaquín</ForeName><Initials>J</Initials></Author><Author ValidYN="Y"><LastName>Quesada</LastName><ForeName>Aurelio</ForeName><Initials>A</Initials></Author><Author ValidYN="Y"><LastName>Toquero</LastName><ForeName>Jorge</ForeName><Initials>J</Initials></Author><Author ValidYN="Y"><LastName>Francés</LastName><ForeName>Roberto Matia</ForeName><Initials>RM</Initials></Author><Author ValidYN="Y"><LastName>Bolao</LastName><ForeName>Ignacio García</ForeName><Initials>IG</Initials></Author><Author ValidYN="Y"><LastName>Berruezo</LastName><ForeName>Antonio</ForeName><Initials>A</Initials></Author><Author ValidYN="Y"><LastName>Sitges</LastName><ForeName>Marta</ForeName><Initials>M</Initials></Author><Author ValidYN="Y"><LastName>Alcalá</LastName><ForeName>Mónica Gimenez</ForeName><Initials>MG</Initials></Author><Author ValidYN="Y"><LastName>Brugada</LastName><ForeName>Josep</ForeName><Initials>J</Initials></Author><Author ValidYN="Y"><LastName>Mont</LastName><ForeName>Lluís</ForeName><Initials>L</Initials></Author><Author ValidYN="Y"><CollectiveName>SPARE II investigators (Spanish Atrial Resynchronization Study II)</CollectiveName></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D003160">Comparative Study</PublicationType><PublicationType UI="D016428">Journal Article</PublicationType></PublicationTypeList><ArticleDate DateType="Electronic"><Year>2012</Year><Month>03</Month><Day>06</Day></ArticleDate></Article><MedlineJournalInfo><Country>England</Country><MedlineTA>Eur J Heart Fail</MedlineTA><NlmUniqueID>100887595</NlmUniqueID><ISSNLinking>1388-9842</ISSNLinking></MedlineJournalInfo><CitationSubset>IM</CitationSubset><CommentsCorrectionsList><CommentsCorrections RefType="CommentIn"><RefSource>Eur J Heart Fail. 2012 Jun;14(6):569-70</RefSource><PMID Version="1">22427435</PMID></CommentsCorrections><CommentsCorrections RefType="CommentIn"><RefSource>Expert Rev Cardiovasc Ther. 2012 Jul;10(7):843-5</RefSource><PMID Version="1">22908917</PMID></CommentsCorrections></CommentsCorrectionsList><MeshHeadingList><MeshHeading><DescriptorName UI="D000368" MajorTopicYN="N">Aged</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D000704" MajorTopicYN="N">Analysis of Variance</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D001281" MajorTopicYN="N">Atrial Fibrillation</DescriptorName><QualifierName UI="Q000000981" MajorTopicYN="N">diagnostic imaging</QualifierName><QualifierName UI="Q000473" MajorTopicYN="N">pathology</QualifierName><QualifierName UI="Q000601" MajorTopicYN="Y">surgery</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D001283" MajorTopicYN="N">Atrioventricular Node</DescriptorName><QualifierName UI="Q000473" MajorTopicYN="Y">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D058406" MajorTopicYN="N">Cardiac Resynchronization Therapy</DescriptorName><QualifierName UI="Q000379" MajorTopicYN="Y">methods</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D017115" MajorTopicYN="N">Catheter Ablation</DescriptorName><QualifierName UI="Q000379" MajorTopicYN="Y">methods</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D016001" MajorTopicYN="N">Confidence Intervals</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D005260" MajorTopicYN="N">Female</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D006801" MajorTopicYN="N">Humans</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D053208" MajorTopicYN="N">Kaplan-Meier Estimate</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008297" MajorTopicYN="N">Male</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D012307" MajorTopicYN="N">Risk Factors</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D013030" MajorTopicYN="N">Spain</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D013223" MajorTopicYN="N">Statistics as Topic</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D014463" MajorTopicYN="N">Ultrasonography</DescriptorName></MeshHeading></MeshHeadingList></MedlineCitation><PubmedData><History><PubMedPubDate PubStatus="entrez"><Year>2012</Year><Month>3</Month><Day>8</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="pubmed"><Year>2012</Year><Month>3</Month><Day>8</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="medline"><Year>2012</Year><Month>10</Month><Day>6</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate></History><PublicationStatus>ppublish</PublicationStatus><ArticleIdList><ArticleId IdType="pubmed">22396459</ArticleId><ArticleId IdType="doi">10.1093/eurjhf/hfs024</ArticleId><ArticleId IdType="pii">hfs024</ArticleId></ArticleIdList></PubmedData></PubmedArticle>
<PubmedArticle><MedlineCitation Status="MEDLINE" Owner="NLM"><PMID Version="1">22395536</PMID><DateCompleted><Year>2012</Year><Month>05</Month><Day>29</Day></DateCompleted><DateRevised><Year>2021</Year><Month>10</Month><Day>21</Day></DateRevised><Article PubModel="Electronic"><Journal><ISSN IssnType="Electronic">1940-087X</ISSN><JournalIssue CitedMedium="Internet"><Issue>60</Issue><PubDate><Year>2012</Year><Month>Feb</Month><Day>28</Day></PubDate></JournalIssue><Title>Journal of visualized experiments : JoVE</Title><ISOAbbreviation>J Vis Exp</ISOAbbreviation></Journal>A new single chamber implantable defibrillator with atrial sensing: a practical demonstration of sensing and ease of implantation. | Implantable cardioverter-defibrillators (ICDs) terminate ventricular tachycardia (VT) and ventricular fibrillation (VF) with high efficacy and can protect patients from sudden cardiac death (SCD). However, inappropriate shocks may occur if tachycardias are misdiagnosed. Inappropriate shocks are harmful and impair patient quality of life. The risk of inappropriate therapy increases with lower detection rates programmed in the ICD. Single-chamber detection poses greater risks for misdiagnosis when compared with dual-chamber devices that have the benefit of additional atrial information. However, using a dual-chamber device merely for the sake of detection is generally not accepted, since the risks associated with the second electrode may outweigh the benefits of detection. Therefore, BIOTRONIK developed a ventricular lead called the Linox(SMART) S DX, which allows for the detection of atrial signals from two electrodes positioned at the atrial part of the ventricular electrode. This device contains two ring electrodes; one that contacts the atrial wall at the junction of the superior vena cava (SVC) and one positioned at the free floating part of the electrode in the atrium. The excellent signal quality can only be achieved by a special filter setting in the ICD (Lumax 540 and 740 VR-T DX, BIOTRONIK). Here, the ease of implantation of the system will be demonstrated. |
14,335 | Continuous versus intermittent monitoring of ventricular rate in patients with permanent atrial fibrillation. | Ventricular rate control (VRC) is an important treatment strategy for patients with permanent atrial fibrillation (AF). We assessed the prevalence of poor VRC and the adequacy of various intermittent monitoring regimens to accurately characterize VRC during permanent AF.</AbstractText>We retrospectively analyzed data from dual chamber implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) patients in the Medtronic Discovery™ Link having permanent AF (AF burden >23 hours/day) and ≥ 365 consecutive days of device data. Poor VRC was defined as a day with the mean ventricular rate during AF >100 beats/minute (bpm) for ICD patients and >90 bpm for CRT-D patients. Intermittent monitoring regimens were simulated from continuous device data by randomly selecting subsets of days in which data were available for analysis. Assessments of poor VRC were computed after replicating 1,000 simulations.</AbstractText>ICD (n = 1,902, age = 71 ± 10) and CRT-D (n = 3,397, age = 72 ± 9) patients were included and followed for 365 days. The prevalence of poor VRC was 24.8% among ICD patients and 28.6% among CRT-D patients. Significantly more patients were identified as having poor VRC with continuous monitoring compared to all intermittent monitoring regimens (sensitivity range = 8%-31%). Furthermore, 11.6% of ICD patients and 17.9% of CRT-D patients experienced ≥ 7 days with poor VRC, to which the sensitivities of annual 7- and 21-day recordings were <7% and <20%, respectively.</AbstractText>A significant proportion of permanent AF patients experience poor VRC that would be missed with random intermittent monitoring. Whether improved knowledge of VRC with continuous monitoring will lead to improved outcomes compared to intermittent monitoring requires further study.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,336 | Incidence and clinical predictors of low defibrillation safety margin at time of implantable defibrillator implantation. | Determination of the defibrillation safety margin (DSM) is the most common method of testing device effectiveness at the time of implantation of implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRTD). Low DSM remains a problem in clinical practice.</AbstractText>The purpose of this study is to ascertain the incidence and clinical predictors of low DSM and the treatment strategies for low DSM in ICD or CRTD recipients.</AbstractText>Selected ICD or CRTD recipients from January 2006 to May 2008 who underwent DSM test at the time of implantation were included. Low DSM patients were defined as patients who had a DSM within 10 J of the maximum delivered energy of the device. These patients were compared to patients who had DSM > 10 J.</AbstractText>This study included 243 patients. Of these, 13 (5.3%) patients had low DSM, and 230 patients had adequate DSM. Patients with low DSM had a high prevalence of amiodarone use (69% vs 13%, p < 0.01), secondary prevention indications (69% vs 30%, p < 0.01), and a trend toward younger age (51 ± 18 vs 58 ± 15 years, p = 0.08). After adjustment for age and sex, amiodarone use was significantly associated with low DSM. All low DSM patients except one obtained adequate DSM after taking additional steps, including discontinuing amiodarone and starting sotalol, RV lead repositioning, adding a subcutaneous array or shock coil, changing single-coil to dual-coil lead, and upgrading to a high output device.</AbstractText>The incidence of low DSM patients is low with high-energy devices. Amiodarone use is associated with low DSM, and its discontinuation or substitution with sotalol is one of a variety of available options for low DSM patients.</AbstractText> |
14,337 | Arrhythmias in women. | There are important gender differences in cardiac electrophysiology that affect the epidemiology, presentation, and prognosis of various arrhythmias. Women have been noted to have higher resting heart rates compared to men. They also have a longer QT interval, which puts them at an increased risk for drug-induced torsades de pointes. Women with atrial fibrillation are at a higher risk of stroke, and they are less likely to receive anticoagulation and ablation procedures compared to men. Women have a lower risk of sudden cardiac death and are less likely to have known coronary artery disease at the time of an event compared to men. Both men and women have been shown to derive an equal survival benefit from implantable cardioverter defibrillators and cardiac resynchronization therapy, although these devices are significantly underutilized in women. Women also appear to have a better response to cardiac resynchronization therapy in terms of reduced numbers of hospitalizations and more robust reverse ventricular remodeling. Further studies are required to elucidate the underlying pathophysiology of these sex differences in cardiac arrhythmias. |
14,338 | Mitral valve prolapse with mid-late systolic mitral regurgitation: pitfalls of evaluation and clinical outcome compared with holosystolic regurgitation. | Mitral regurgitation (MR) of mitral valve prolapse predominates in late systole but may be holosystolic or purely mid-late systolic, but the impact of MR timing on MR left ventricular and left atrial consequences and outcome is unknown. Whether effective regurgitant orifice (ERO) by the flow convergence method is similarly linked to outcome in mid-late systolic MR and holosystolic MR is uncertain.</AbstractText>We comprehensively and prospectively quantified MR in 111 patients with mitral valve prolapse and mid-late systolic MR and matched them to 90 patients with mitral valve prolapse and holosystolic MR for age, gender, atrial fibrillation, ejection fraction, and ERO (flow convergence). Mid-late systolic MR versus holosystolic MR groups were well matched, including for comorbidity, blood pressure, and heart rate (all P>0.10). Mid-late systolic MR versus holosystolic MR caused similar color jet area, midsystolic regurgitant flow, and peak velocity (P>0.40). Despite identical ERO (0.25±0.15 versus 0.25±0.15 cm(2); P=0.53), the shorter duration of mid-late systolic MR (233±56 versus 426±50 ms; P<0.0001) yielded lower regurgitant volume (24.8±13.4 versus 48.6±25.6 mL; P<0.0001). MR consequences, systolic pulmonary pressure, and left ventricular and left atrial volume index (all P<0.001) were more benign in mid-late systolic MR versus holosystolic MR. Under medical management, fewer cardiac events (5 years: 15.8±4.6% versus 40.4±6.1%; P<0.0001) occurred in mid-late systolic MR versus holosystolic MR, requiring less mitral surgery. Multivariable analysis confirmed the independent association of mid-late systolic MR with benign consequences and outcomes (all P<0.01). Absolute ERO was not linked to outcome, in contrast to regurgitant volume.</AbstractText>MR of mitral valve prolapse that is purely mid-late systolic causes more benign consequences and outcomes than holosystolic MR. Assessment may be misleading because jet area and ERO by flow convergence appear similar to those of holosystolic MR. However, shorter MR yields lower regurgitant volume, consequences, and benign outcomes. Instantaneous ERO by flow convergence should be interpreted in context, and in mid-late systolic MR, regurgitant volume provides information more reflective of MR severity. Therefore, for clinical management and surgical referral, clinicians should carefully take into account the timing and consequences of MR.</AbstractText> |
14,339 | Outcome after out-of-hospital cardiac arrest witnessed by EMS: changes over time and factors of importance for outcome in Sweden. | Among patients who survive after out-of-hospital cardiac arrest (OHCA), a large proportion are recruited from cases witnessed by the Emergency Medical Service (EMS), since the conditions for success are most optimal in this subset.</AbstractText>To evaluate outcome after EMS-witnessed OHCA in a 20-year perspective in Sweden, with the emphasis on changes over time and factors of importance.</AbstractText>All patients included in the Swedish Cardiac Arrest Register from 1990 to 2009 were included.</AbstractText>There were 48,349 patients and 13.5% of them were EMS witnessed. There was a successive increase in EMS-witnessed OHCA from 8.5% in 1992 to 16.9% in 2009 (p for trend<0.0001). Among EMS-witnessed OHCA, the survival to one month increased from 13.9% in 1992 to 21.8% in 2009 (p for trend<0.0001). Among EMS-witnessed OHCA, 51% were found in ventricular fibrillation, which was higher than in bystander-witnessed OHCA, despite a lower proportion with a presumed cardiac aetiology in the EMS-witnessed group. Among EMS-witnessed OHCA overall, 16.0% survived to one month, which was significantly higher than among bystander-witnessed OHCA. Independent predictors of a favourable outcome were: (1) initial rhythm ventricular fibrillation; (2) cardiac aetiology; (3) OHCA outside home and (4) decreasing age.</AbstractText>In Sweden, in a 20-year perspective, there was a successive increase in the proportion of EMS-witnessed OHCA. Among these patients, survival to one month increased over time. EMS-witnessed OHCA had a higher survival than bystander-witnessed OHCA. Independent predictors of an increased chance of survival were initial rhythm, aetiology, place and age.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,340 | The difference in myocardial injuries and mitochondrial damages between asphyxial and ventricular fibrillation cardiac arrests. | Ventricular fibrillation (VF) and asphyxia account for most cardiac arrests but differ in cardiac arrest course, neurologic deficit, and myocardial damage. In VF resuscitation, cardiac mitochondria were known to be damaged via excess generation of reactive oxygen species. This study evaluated the difference of cardiac mitochondrial damages between VF and asphyxial cardiac arrests.</AbstractText>In the VF + electrical shock (ES) group, VF was induced and untreated for 5 minutes, followed by 1 minute of cardiopulmonary resuscitation (CPR) and 1 ES of 5 J. Animals were killed immediately after ES. In the asphyxia group, cardiac arrest was induced by airway obstruction, and then pulselessness was maintained for 5 minutes, followed by 1 minute of CPR. The animals were killed immediately after CPR. The histology and ultrastructural changes of myocardium and complex activities and respiration of mitochondria were evaluated. The mitochondrial permeability transition pore opening was measured based on mitochondrial swelling rate.</AbstractText>The histopathologic examinations showed myocardial necrosis and mitochondrial damage in both cardiac arrests. Instead of regional damages of myocardium in the VF + ES group, the myocardial injury in the asphyxia group distributed diffusely. The asphyxia group demonstrated more severe mitochondrial damage than the VF + ES group, which had a faster mitochondrial swelling rate, more decreased cytochrome c oxidase activity, and more impaired respiration.</AbstractText>Both VF and asphyxial cardiac arrests caused myocardial injuries and mitochondrial damages. Asphyxial cardiac arrest presented more diffuse myocardial injuries and more severe mitochondrial damages than VF cardiac arrest.</AbstractText>Copyright © 2012 Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,341 | Simultaneous left anterior descending and right coronary stent thrombosis after aspirin withdrawal. | ST-segment elevation myocardial infarction is usually caused by plaque rupture and subsequent thrombosis of a single culprit vessel. In rare occasions, simultaneous thrombosis of 2 coronary arteries occurs, which is usually associated with a worse prognosis. Although surgery provokes hemodynamic stress, leading in some instances to myocardial ischemia due to supply/demand mismatch, other factors may also contribute to postoperative myocardial infarction. We present a case of postoperative simultaneous left anterior descending and right coronary stent thrombosis that followed cessation of long-term aspirin therapy in a patient with stable coronary artery disease. This case raises concerns with drug-eluting stents due to the higher potential for late stent thrombosis related to delayed endothelialization of the stent struts. Physicians should be very cautious when deciding to withdraw antiplatelet therapy preoperatively to avoid rebound coronary thrombosis. |
14,342 | Evaluation and management of arrhythmia in the athletic patient. | Athletes may present with palpitations, syncope, or arrest resulting in the diagnosis of arrhythmia, or screening may result in diagnosis of conditions with predisposition to arrhythmia. This chapter focuses on 3 common arrhythmic conditions in athletes-atrial fibrillation, premature ventricular contractions (PVCs), and the athlete with an implanted device. (1) Atrial fibrillation: most studies show that atrial fibrillation is more common in competitive athletes, particularly those participating in long-term endurance sports. Postulated mechanisms include morphologic changes such as atrial dilatation, autonomic changes such as increased vagal tone, or inflammatory changes due to sports participation. Treatment options include long-term antiarrhythmic agents, "pill in the pocket" medications, or radiofrequency ablation, a highly successful procedure in athletes. (2) Premature ventricular contractions: data conflict on whether the incidence of PVCs is increased in highly trained individuals. Very frequent PVCs in athletes, however, can be a manifestation of underlying heart disease, and athletes presenting with PVCs should undergo evaluation. In the absence of underlying heart disease, PVCs do not carry a poor prognosis, and US guidelines do not recommend restriction from sports. (3) Implanted devices: the safety of sports for the athlete with an implanted device is unknown, and current guidelines recommend against participation in vigorous competitive sports, based on postulated risks including failure to defibrillate and risk of injury. Many athletes with defibrillators and pacemakers do participate in sports. Ongoing research will better delineate the risks of sports for the athlete with an implanted device. |
14,343 | Prevalence of, associations with, and prognostic value of tricuspid annular plane systolic excursion (TAPSE) among out-patients referred for the evaluation of heart failure. | Prevalence, predictors, and prognostic value of right ventricular (RV) function measured by the tricuspid annular plane systolic excursion (TAPSE) in patients with chronic heart failure (CHF) symptoms with a broad range of left ventricular ejection fraction (LVEF) are unknown.</AbstractText>Of 1,547 patients, mean (±SD) age was 71 ± 11 years, 48% were women, median (interquartile range [IQR]) TAPSE was 18.5 (14.0-22.7) mm, mean LVEF was 47 ± 16%, 47% had LVEF ≤45% and 67% were diagnosed with CHF, defined as systolic (S-HF) if LVEF was ≤45% and as heart failure with preserved ejection fraction (HFPEF) if LVEF was >45% and treated with a loop diuretic. During a median (IQR) follow-up of 63 (41-75) months, mortality was 34%. In multivariable analysis, increasing age, N-terminal pro-B-type natriuretic peptide (NT-proBNP), New York Heart Association functional class, right atrial volume index, and transtricuspid pressure gradient; lower TAPSE, diastolic blood pressure, and hemoglobin; and atrial fibrillation (AF) or COPD were associated with an adverse prognosis. Receiver operating characteristic curve analysis identified a TAPSE of 15.9 mm as the best prognostic threshold (P = .0001); 47% of S-HF and 20% of HFPEF had a TAPSE of <15.9 mm. The main associations with a TAPSE <15.9 mm were higher NT-proBNP, presence of atrial fibrillation and presence of LV systolic dysfunction.</AbstractText>In patients with CHF, low values for TAPSE are common, especially in those with reduced LVEF. TAPSE, unlike LVEF, was an independent predictor of outcome.</AbstractText>Copyright © 2012 Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,344 | Clinical comparison of ICD detection algorithms that include rapid-VT zones. | The safe use of antitachycardia pacing (ATP) to terminate rapid ventricular tachycardias (VTs) (cycle length 240-320 ms) is predicated on the ability of implantable cardioverter defibrillators (ICDs) to distinguish rapid VT from ventricular fibrillation (VF). We set out to compare the time to device charging following the induction of VF of various ICD multizone detection algorithms for rapid VT/VF discrimination.</AbstractText>Data on the time to device charging following the induction of VF at the time to device implantation were collected on 62 consecutive patients in a nonrandomized prospective cohort fashion. Multizone programming for the Boston Scientific, Medtronic, and St. Jude Medical devices was based on prior clinically validated data. Sixty-two subjects were studied (Boston Scientific = 16, Medtronic = 27, St. Jude Medical = 19) and 124 tests for VF detection were performed (Boston Scientific = 32, Medtronic = 54, St. Jude Medical = 38). Mean time to charging was significantly prolonged in the Boston Scientific group as was the percentage of tests where charge initiation occurred >5 seconds from VF-induction: 4.24, 3.99, and 3.00 seconds and 19%, 4%, and 0% for the Boston Scientific, Medtronic, and St. Jude Medical groups, respectively, P < 0.05. ATP was the first therapy administered in 9.4% of tests in the Boston Scientific group.</AbstractText>The Boston Scientific multizone VT/VF discrimination algorithm results in a prolonged time to VF detection, and consequently, prolonged time to appropriate initiation of device charging. Further studies are needed to determine whether prolonged detection times lead to clinically significant events.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,345 | Nerve sprouting contributes to increased severity of ventricular tachyarrhythmias by upregulating iGluRs in rats with healed myocardial necrotic injury. | Sympathetic nerve sprouting in healed myocardial infarction (MI) has been associated with high incidences of lethal arrhythmias, but the underlying mechanisms are largely unknown. This study sought to test that sympathetic hyperinnervation and/or MI remodels the myocardial glutamate signaling and ultimately increases the severity of ventricular tachyarrhythmias. Myocardial necrotic injury (MNI) was created by liquid nitrogen freeze-thawing across an intact diaphragm to mimic MI. Cardiac sympathetic hyperinnervation was induced by chronic subcutaneous injection of 4-methylcatechol, a potent stimulator of nerve growth factor expression. The results showed that sympathetic hyperinnervation with or without MNI upregulated the myocardial expression of ionotropic glutamate receptors (iGluRs), including NMDA receptor (NMDAR) and AMPA receptor (AMPAR), and induced cardiomyocyte apoptosis. Intravenous infusion with either NMDA (12 mg/kg) or AMPA (15 mg/kg) triggered ventricular tachycardia and ventricular fibrillation in rats with healed MNI plus sympathetic hyperinnervation; these arrhythmias were prevented by respective antagonist of NMDAR or AMPAR. We conclude that MNI with sympathetic nerve sprouting upregulates the expression of NMDAR and AMPAR in the myocardium and this impact in turn enhances cardiac responses to stimulations of iGluRs and thus increases the incidence of ventricular tachyarrhythmias. |
14,346 | [Recent advances in natriuretic peptide family genes and cardiovascular diseases]. | Natriuretic peptide family consists of several hormones produced by cardiomyocyte, including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP). They possess similar gene structures and protective effects of cardiovascular physiology, such as anti-hypertrophy, anti-fibrosis, myocardial relaxation and blood pressure regulation. The corresponding natriuretic peptide receptor A, B and C mediate multiple effects of natriuretic peptides to maintain cardiovascular homeostasis. Specially, natriuretic peptide receptor-A preferentially binds ANP and BNP, while natriuretic peptide receptor-B is more selective for C-type natriuretic peptides. Natriuretic peptide receptor-C(NPR-C), binding all kinds of natriuretic peptides, clears natriuretic peptides from the circulation through receptor-mediated internalization and degradation. BNP levels were reported to be a good predictor of left ventricular dysfunction and decompensated heart failure from a clinical standpoint. BNP infusion is an effective treatment for acute heart failure. Investigations on natriuretic peptides' single nucleotide polymorphisms and biological function suggested that they could be associated with several cardiovascular diseases, such as atrial fibrillation, cardiomyopathy, heart failure and so on. Transgenic mice with natriuretic peptides and their receptors gene deletion display myocardial hypertrophy and fibrosis, which are associated with the development of hypertension, cardiomyopathy and heart failure. Certain stimuli triggering cardiac hypertrophy and ischemic injuries may be involved in regulating gene expression of natriuretic peptides and their receptors. Therefore, advances in understanding of natriuretic peptide family genes and their regulatory mechanisms will lead to greater insight into the pathogenesis of cardiovascular diseases and blaze a new trail in clinical treatment. |
14,347 | Infective endocarditis presenting as ST-elevation myocardial infarction: an angiographic diagnosis. | While systemic embolic events occur with relative frequency in infective endocarditis (IE), coronary embolization remains an uncommon cause of ST elevation myocardial infarction. Herein we report a case of ventricular fibrillation and anterior ST elevation myocardial infarction occurring in a patient initially presenting with septic shock. Angiography proved diagnostic for IE of a native bicuspid aortic valve complicated by root abscess and left anterior descending artery occlusion. Histologic examination of the embolectomy specimen from the left anterior descending artery confirmed the presence of thrombus and bacteria. The present case highlights difficulties in identifying and managing patients with coronary embolism of vegetations from IE. |
14,348 | Hypertrophic cardiomyopathy with longevity to 90 years or older. | Hypertrophic cardiomyopathy (HC) is the most common cause of sudden death in the young, but survival to particularly advanced age is less well appreciated. The investigators report the prevalence, clinical features, and demographics of patients with HC surviving to ≥90 years of age. Of 1,297 patients with HC in the Hypertrophic Cardiomyopathy Center database (Minneapolis Heart Institute Foundation), 26 (2.0%) were identified who had achieved the age of ≥90 years; 18 (69%) were women. HC diagnosis came late in life, at 61 to 92 years (mean 80 ± 8; ≥75 years in 21 patients), recognized fortuitously by the detection of a heart murmur or during family screening (n = 6) or after onset of new symptoms (n = 20). At most recent evaluation (or death) patients were aged 90 to 96.7 years (mean 92.2 ± 2), with 6 presently alive at 91 to 96 years of age; HC did not appear to be the primary cause of death in any patient. Left ventricular wall thicknesses were 15 to 31 mm (mean 20 ± 3); 8 patients (31%) had obstruction to left ventricular outflow at rest (peak instantaneous gradients, 38 to 135 mm Hg). Significant HC-related complications occurred in 13 patients (50%), including progressive heart failure symptoms, atrial fibrillation, and nonfatal embolic stroke. Although no patient died suddenly, 13 (50%) nevertheless carried conventional HC risk markers. A greater proportion of cohort patients reached ≥90 years of age (2.0%) than expected in the general population (0.8%) (p <0.001). In conclusion, HC may be unrecognized until late in life and is consistent with survival to particularly advanced age into the 10th decade of life without the need for major HC-related treatment interventions, and with demise ultimately largely unrelated to this disease. This principle regarding the natural history of HC can afford a measure of reassurance to many patients. |
14,349 | Prognostic value of left atrium remodeling after primary percutaneous coronary intervention in patients with ST elevation acute myocardial infarction. | The purpose of this study is to assess the relationship between left atrial (LA) size and outcome after acute myocardial infarction (AMI) in patients undergoing primary percutaneous coronary intervention (PCI) and to evaluate dynamic changes in LA size during long-term follow-up. Echocardiographic analyses were performed on 253 AMI patients (174 male and 79 female, 65.4 ± 13.7 yr) undergoing PCI. These subjects were studied at baseline and at 12 months. Clinical follow-up were done at 30.8 ± 7.5 months. We assessed LA volume index (LAVI) at AMI-onset and at 12-month. Change of LAVI was an independent predictor of new onset of atrial fibrillation or hospitalization for heart failure (P = 0.002). Subjects who survived the 12-month period displayed an increased LAVI mean of 1.86 ± 4.01 mL/m(2) (from 26.1 ± 8.6 to 28.0 ± 10.1 mL/m(2), P < 0.001). The subject group that displayed an increased LAVI correlated with a low left ventricular ejection fraction, large left ventricle systolic and diastolic dimensions and an enlarged LA size. In conclusion, change of LAVI is useful parameter to predict subsequent adverse cardiac event in AMI patients. Post-AMI echocardiographic evaluation of LAVI provides important prognostic information that is significantly greater than that obtained from clinical and laboratory parameters alone. |
14,350 | A case of intra-operative ventricular fibrillation: Electro-cauterization, undiagnosed Takotsubo cardiomyopathy or long QT syndrome? | Cardiac arrest in the perioperative setting is an extremely serious event that is estimated to occur between 4.6 and 19.7 per 10,000 anesthetics.(1-5) While risk factors for cardiac complications can be identified pre- operatively, in many cases workup of risk factors are not indicated by standard pre-operative testing guidelines.</AbstractText>We present a case of a 47-year-old female undergoing an elective bilateral mastectomy who suddenly converted to ventricular fibrillation. While ventricular fibrillation is not a unique finding, our search for its etiology revealed two previously undiagnosed cardiac conditions, and possible electro- cautery induced ventricular fibrillation.</AbstractText>In this case study, we discuss the possible etiology of ventricular fibrillation in our patient and highlight the importance pre-operative patient investigation and history provide.</AbstractText>Searching for the potential causes that may have contributed to the cardiac arrest is an extremely useful exercise as it allows us to better prepare patients pre-operatively, improve intra-operative care, and prevent future cardiac events.</AbstractText>Copyright © 2012 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
14,351 | Serum Potassium Changes During Therapeutic Hypothermia After Out-of-Hospital Cardiac Arrest-Should It Be Treated? | Therapeutic hypothermia (TH) after out-of-hospital cardiac arrest (OHCA) is associated with adverse events, for example hypokalemia and arrhythmias. In the present study, we report the impact of serum potassium changes related to the rate of cardiac arrhythmias, and the advantages and disadvantages of potassium supplementation are discussed.</AbstractText>Fifty-four consecutive patients suffering from OHCA and treated with TH (32-34°C) for 24 hours at one University Hospital were included and followed for 48 hours.</AbstractText>Serum potassium levels decreased during cooling from a median admission value of 4.0 mmol/L (quartiles 3.6-4.5 mmol/L) to a nadir of 3.6 mmol/L (3.5-3.9 mmol/L) 6 hours after target temperature (p=0.005), and 76% reached values of <3.5 mmol/L. During rewarming, serum potassium increased, with 15% reaching values of >5.5 mmol/L. Potassium supplementation was initiated at 3.5 mmol/L (quartiles 3.2-3.6 mmol/L) and stopped at 4.5 mmol/L (4.1-4.8 mmol/L). A total of 11% of patients experienced ventricular fibrillation (VF) or ventricular tachycardia (VT). Potassium levels in patients experiencing VF or VT were lower, though not significantly (p=0.119) compared to the rest of the patients.</AbstractText>Serum potassium decreases significantly during the induction of TH (p=0.005). Potassium levels were not found to be different in patients with and without VF/VT in this study, perhaps due to the low number of patients, as a difference has been seen in other studies. It is recommended that an infusion of supplementary potassium be initiated during the early cooling phase in order to avoid severe hypokalemia (serum potassium <3.0 mmol/L) and terminated in due time before normothermia is reached during rewarming in order to avoid severe hyperkalemia (serum potassium >5.5 mmol/L), as serum potassium increases during rewarming.</AbstractText> |
14,352 | SkM1 and Cx32 improve conduction in canine myocardial infarcts yet only SkM1 is antiarrhythmic. | Reentry accounts for most life-threatening arrhythmias, complicating myocardial infarction, and therapies that consistently prevent reentry from occurring are lacking. In this study, we compare antiarrhythmic effects of gene transfer of green fluorescent protein (GFP; sham), the skeletal muscle sodium channel (SkM1), the liver-specific connexin (Cx32), and SkM1/Cx32 in the subacute canine infarct.</AbstractText>Immediately after ligation of the left anterior descending artery, viral constructs were implanted in the epicardial border zone (EBZ). Five to 7 days later, efficient restoration of impulse propagation (narrow QRS and local electrogram duration) occurred in SkM1, Cx32, and SkM1/Cx32 groups (P< 0.05 vs. GFP). Programmed electrical stimulation from the EBZ induced sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) in 15/22 GFP dogs vs. 2/12 SkM1, 6/14 Cx32, and 8/10 SkM1/Cx32 (P< 0.05 SkM1 vs. GFP). GFP, SkM1, and SkM1/Cx32 had predominantly polymorphic VT/VF, whereas in Cx32 dogs, monomorphic VT predominated (P< 0.05 for Cx32 vs. GFP). Tetrazolium red staining showed significantly larger infarcts in Cx32- vs. GFP-treated animals (P< 0.05).</AbstractText>Whereas SkM1 gene transfer reduces the incidence of inducible VT/VF, Cx32 therapy to improve gap junctional conductance results in larger infarct size, a different VT morphology, and no antiarrhythmic efficacy.</AbstractText> |
14,353 | Simultaneous comparison of many triphasic defibrillation waveforms. | Biphasic defibrillation waveforms are now accepted as being more effective at terminating ventricular fibrillation (VF) than monophasic waveforms. If two phases are better than one, this naturally leads to the hypothesis that additional phases improve efficacy. This study tests the hypothesis by adding one additional phase. We examined the efficacy of 18 different triphasic waveforms simultaneously.We tested the rate of recovery, i.e., successful defibrillation, of 21 guinea pigs (820-1,050 g) using triphasic, monophasic and biphasic defibrillation waveforms. The biphasic and monophasic were control waveforms. VF was electrically induced twenty times per animal and a single defibrillation attempt was made using a test waveform VF episode. Every waveform was adjusted to the energy required to defibrillate that animal 50% of the time, using a biphasic waveform as a control. The success rate of each triphasic waveform was pair-wise compared to the biphasic and monophasic control using the adjusted McNemar statistical test.Of the 18 triphasic waveforms tested, two were significantly poorer than the monophasic control (p<0.05). One was superior to the biphasic waveform (p<0.1), but not statistically so. We concluded that, while adding a phase to a monophasic waveform does improve efficacy, adding an additional phase to a biphasic waveform does not necessarily improve efficacy. |
14,354 | Atrial-selective prolongation of refractory period with AVE0118 is due principally to inhibition of sodium channel activity. | The action of AVE0118 to prolong effective refractory period (ERP) in atria but not in ventricles is thought to be due to its inhibition of IKur. However, in nonremodeled atria, AVE0118 prolongs ERP but not action potential duration (APD70-90), which can be explained with the inhibition of sodium but not potassium channel current. ERP, APD, and the maximum rate of increase of the AP upstroke (Vmax) were measured in the canine-isolated coronary-perfused right atrial and in superfused ventricular tissue preparations. Whole-cell patch-clamp techniques were used to measure sodium channel current in HEK293 cells stably expressing SCN5A. AVE0118 (5-10 μM) prolonged ERP (P < 0.001) but not APD70 and decreased Vmax (by 15%, 10 μM, P < 0.05; n = 10 for each). Ventricular ERP, APD90, and Vmax were not changed significantly by 10 μM AVE0118 (all P = ns; n = 7). AVE0118 effectively suppressed acetylcholine-mediated persistent atrial fibrillation. AVE0118 (10 μM) reduced peak current amplitude of SCN5A-WT current by 36.5% ± 6.6% (P < 0.01; n = 7) and shifted half-inactivation voltage (V0.5) of the steady-state inactivation curve from -89.9 ± 0.5 to -96.0 ± 0.9 mV (P < 0.01; n = 7). Our data suggest that AVE0118-induced prolongation of atrial, but not ventricular ERP, is due largely to atrial-selective depression of sodium channel current, which likely contributes to the effectiveness of AVE0118 to suppress atrial fibrillation. |
14,355 | Ventricular fibrillation in an ambulatory patient supported by a left ventricular assist device: highlighting the ICD controversy. | Left ventricular assist devices (LVADs) provide an effective means of managing advanced pump failure as a means of bridging to cardiac transplantation or as permanent therapy. Although ventricular arrhythmias remain common post-LVAD implantation, such therapy may allow malignant arrhythmias to be tolerated hemodynamically. This report describes the clinical findings in a patient who had likely been in a ventricular tachyarrhythmia for several days and presented in ventricular fibrillation, ambulatory, and mentating normally. This report, with previous similar reports, is additive to the body of evidence that LVADs alter the physiologic impact of ventricular arrhythmias in advanced heart failure and highlights the need for thoughtful programming of implantable cardioverter defibrillator therapies in these patients. |
14,356 | Cross-sectional study of treatment strategies on atrial fibrillation. | Despite the high prevalence and clinical importance of atrial fibrillation (AF), there is no Brazilian study describing the clinical profile of patients with AF and the most used treatment strategy (rhythm control vs. rate control).</AbstractText>Assess the most common treatment on AF in an outpatient specialized clinic for management of AF. In addition, the clinical profile of the population studied was provided.</AbstractText>Cross-sectional study assessing the most used strategy for atrial fibrillation control in 167 patients. The clinical profile was also described. A standardized form was used for data collection and statistical analysis was performed by SPSS 13.0 software.</AbstractText>In This high risk population for thromboembolic events (61% had CHADS(2) ≥ 2), 54% of patients had paroxysmal or persistent AF, 96.6% were on vitamin K antagonists or acetylsalicylic acid, and 76.6% on beta-blocker (rate control 81,2% x rhythm control 58,8%; p < 0.05). Heart rate control was the most used strategy (79.5% x 20.5%; p < 0.001). A statistical tendency towards more patients with ventricular dysfunction (15.2% x 2.9%; p = 0.06), CHADS(2) ≥ 2 (60.5% x 39.5%; p = 0.07) and heart valve diseases (25.8% x 11.8%; p = 0.08) was observed in the heart rate control group.</AbstractText>In this high risk population for thromboembolic events, the rate control strategy was the most used.</AbstractText> |
14,357 | Acute effects of granulocyte colony-stimulating factor on early ventricular arrhythmias after coronary occlusion in rats. | To evaluate the acute effects of colony-stimulating factor (G-CSF) on ventricular arrhythmias after coronary occlusion in rats.</AbstractText>Male Wistar rats (10 weeks) received G-CSF (100 μg.kg(-1)) or vehicle. Thirty minutes later, animals were infarcted by coronary occlusion under artificial respiration. Electrocardiogram was monitored for 30 min to evaluate ventricular arrhythmias.</AbstractText>G-CSF treatment reduced the number of premature ventricular beats and the number and duration of ventricular tachycardia. The incidence of ventricular fibrillation was significantly reduced by G-CSF (MI-Cont: 11.2 ± 2.4 vs. MI-GCSF: 5.4 ± 1 events; P < 0.05). However, total duration of ventricular fibrillation was not altered (MI-Cont: 84 ± 16 vs. MI-GCSF: 76 ± 13 sec).</AbstractText>Acute administration of G-CSF before coronary ligature in rats reduces the incidence of ventricular premature beats and ventricular tachycardia, suggesting a possible direct electrophysiological effect of this cytokine independently of its genomic effects. However, the data suggest that G-CSF treatment may affect the spontaneous recovery from ventricular fibrillation. Acute G-CSF administration acts directly on cardiac electrophysiology, different from chronic treatment.</AbstractText> |
14,358 | Mouse heart rate in a human: diagnostic mystery of an extreme tachyarrhythmia. | We report telemetry recording of an extreme non-fatal tachyarrhythmia noted in a hospitalized quadriplegic male with history of atrial fibrillation where the average ventricular conduction rate was found to be about 600 beats per minute and was associated with transient syncope. A medical literature review suggests that the fastest human ventricular conduction rate reported to date in a tachyarrhythmia is 480 beats per minute. We therefore report the fastest human heart rate noted in a tachyarrhythmia and the most probable mechanism of this arrhythmia being a rapid atrial fibrillation with 1:1 conduction in the setting of probable co-existing multiple bypass tracts. |
14,359 | Ventricular Tachycardia Precipitated by Short-long-short Sequence in a Patient with Implantable-cardioverter Defibrillator. | Abrupt changes in heart rate, particularly short-long-short sequences in the ventricular cycle length (CL), might precede initiation of ventricular tachycardia/fibrillation (VT/VF). These changes may be facilitated or caused by pacing activity in patients with pacemakers or implantable-cardioverter defibrillators (ICDs). We describe a patient with two episodes of acquired VT precipitated by short-long-short sequences and diagnosed from the ICD recordings. In such cases, the knowledge of the device parameters is extremely important for a correct diagnosis and management. |
14,360 | Paroxysmal atrial fibrillation triggered by a monomorphic ventricular couplet in a patient with acute coronary syndrome. | Atrial fibrillation is a common arrhythmia in patients suffering from acute myocardial infarction, however its pathophysiological mechanisms are not fully understood. We describe the unusual case of a 76-year old woman admitted for non-ST-segment elevation myocardial infarction, who developed multiple episodes of paroxysmal atrial fibrillation triggered by monomorphic ventricular couplets. Beta-blocking and amiodarone therapy resulted efficacious in preventing arrhythmic recurrences. We then discuss the possible arrhythmogenic mechanisms, with special emphasis on the unique electrophysiological, hemodynamic, cellular and anatomical milieu created by acute myocardial ischemia. |
14,361 | The importance of exercise echocardiography for clinical decision making in primary mitral regurgitation. | Primary mitral regurgitation is generally an insidious disease with late onset of symptoms. Current European and American guidelines recommend surgery in severe primary mitral regurgitation when symptoms, overt left ventricular dysfunction, pulmonary hypertension or atrial fibrillation, occur. However, recent large studies reported an improved outcome in asymptomatic patients with severe mitral regurgitation referred for early mitral valve repair despite the risk of operative mortality or mitral valve replacement. Moreover, primary mitral regurgitation appears to have an important dynamic character in up to one-third of patients. This article provides an overview of the incremental evidence of the ability of exercise echocardiography to assess the functional repercussions of mitral regurgitation and the identification of high-risk patients who might benefit from early referral for surgery. |
14,362 | Evidence that 2-aminoethoxydiphenyl borate provokes fibrillation in perfused rat hearts via voltage-independent calcium channels. | We tested whether 2-aminoethoxydiphenyl borate (2-APB) induces arrhythmia in perfused rat hearts and whether this arrhythmia might result from the activation of voltage-independent calcium channels. Rat hearts were Langendorff perfused and beat under sinus rhythm. An isovolumic balloon inserted into the left ventricle was used to record mechanical function while bipolar electrograms were recorded from electrodes sutured to the base and the apex of hearts. Western and immunofluorescence analyses were performed on rat left ventricular protein extracts and left ventricular frozen sections, respectively. Rat ventricular myocytes express Orai 1 and Orai 3, and ventricle also contains the Orai regulator Stim1. Rat hearts (n=5) perfused with Krebs-Henseleit (KH) alone maintained sinus rhythm at 4.8 ± 0.1 Hz and stable mechanical function. By contrast, perfusing hearts (n=5) with (KH+22 μM 2-APB) provoked a period of tachycardic ectopy at rates of up to 10.8 ± 0.2 Hz. As perfusion with (KH+22 μM 2-APB) continued, the rate of spontaneous ventricular depolarization increased to 21.8 ± 1.2 Hz and became disorganized. Heart mechanical function collapsed as developed pressure decreased from 87 ± 8.8 to 3.5 ± 1.9 mm Hg. Flow rate did not change between normal (16.6 ± 0.9 ml/min) and fibrillating (17.4 ± 0.8 ml/min) hearts. The addition of 20 μM 1-[2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl) propoxy]ethyl-1H-imidazole (SKF-96365) to (KH+22 μM 2-APB) perfusates (n=4) restored sinus rhythm and heart mechanical output. These data indicate that activating myocardial voltage-independent calcium channels, possibly the Orais, may be a novel cause of ventricular arrhythmia. |
14,363 | Usefulness of cardiac computed tomographic delayed contrast enhancement of the left atrial appendage before pulmonary vein ablation. | Left atrial appendage (LAA) contrast filling defects are commonly found in patients undergoing multidetector cardiac computed tomography (CCT) before catheter ablation of atrial fibrillation. Delayed CCT allows quantification of the LAA delayed/initial attenuation ratio and improves accuracy for LAA thrombus detection, which may obviate routine transesophageal echocardiography (TEE) before ablation. CCT with contrast-enhanced scans (initial CCT) and with noncontrast-enhanced scans (delayed CCT) was performed in 176 patients. LAA was evaluated for filling defects. LAA apex, left atrial (LA) body, and ascending aorta (AA) attenuations (Hounsfield units) were measured on initial and delayed cardiac computed tomograms to calculate LAA, LA, LAA/LA, and LAA/AA attenuation ratios. LAA, initial LAA/LA, and initial LAA/AA attenuation ratios differed significantly in patients with versus without filling defects on cardiac computed tomogram, those with atrial fibrillation versus normal sinus rhythm, and those with abnormal left ventricular ejection fraction versus larger LA volumes (p <0.05). In 70 patients (40%) who underwent TEE, 13 LAA filling defects were seen on initial cardiac computed tomogram. Two defects persisted on delayed cardiac computed tomogram and thrombus was confirmed on transesophageal echocardiogram. Sensitivity, specificity, and positive and negative predictive values of initial CCT for LAA thrombi detection were 100%, 84%, 15%, and 100%, respectively. With delayed CCT these values increased to 100%. Intraobserver and interobserver reproducibilities for cardiac computed tomographic measurements were good (intraclass correlation 0.72 to 0.97, kappa coefficients 0.93 to 1.00). In conclusion, delayed CCT provided an increase in diagnostic accuracy of CCT for detection of LAA thrombus in patients with atrial fibrillation before ablation, which may decrease the need for routine TEE before the procedure. |
14,364 | Evaluation oF FactORs ImpacTing CLinical Outcome and Cost EffectiveneSS of the S-ICD: design and rationale of the EFFORTLESS S-ICD Registry. | Leads in and on the heart of the transvenous implantable cardioverter defibrillator (ICD) form the Achilles' heel of this system due to potential for peri- and postimplant complications. The S-ICD is a newer generation of the ICD that does not require leads on the heart or in the vasculature. We present the rationale and study design of the Evaluation oF FactORs ImpacTing CLinical Outcome and Cost EffectiveneSS of the S-ICD (EFFORTLESS S-ICD) Registry which was designed to evaluate the long-term performance of the S-ICD including patient quality of life and long-term resource utilization.</AbstractText>The Registry is an observational, nonrandomized, standard of care evaluation to be conducted at approximately 50 investigational centers in Europe and New Zealand where the S-ICD is approved for use and distribution. Clinical Registry endpoints include perioperative (30 days postimplant) complication-free rate, 360-day complication-free rate, and percentage of inappropriate shocks for atrial fibrillation and supraventricular ventricular tachyarrhythmia. Other endpoints include patient-reported outcomes (e.g., quality of life) and hospital personnel implant and follow-up experience with the S-ICD system.</AbstractText>Results from EFFORTLESS will build on and expand the initial published experience with the S-ICD, which demonstrated that the device successfully and consistently detects and treats episodes of sustained ventricular tachyarrhythmias. The Registry will also evaluate the patients' perspective of how it is to live with an S-ICD as compared to a contemporary transvenous system and track the experience of implanting physicians and personnel performing patient follow-up with a completely subcutaneous system.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,365 | Successful reduction of a high defibrillation threshold by a combined implantation of a subcutaneous array and azygos vein lead. | A 72-year-old man with nonischemic cardiomyopathy was referred because his implantable cardioverter defibrillator had failed to terminate spontaneous ventricular fibrillation (VF). Defibrillation threshold (DFT) testing confirmed that 830-V shocks failed to defibrillate VF despite optimization of the biphasic waveform and reversal of shock polarity. The placement of a new right ventricular lead and the addition of a subcutaneous array failed to defibrillate VF at 830 V. The combination of a subcutaneous array and azygos vein coil successfully defibrillated VF. The mechanism for successful DFT reduction was likely greater current supplied to the posterior basal left ventricle by the azygos vein lead. |
14,366 | Ventricular fibrillation risk factors in over one thousand patients with accessory pathways. | Published data concerning risk factors of VF in WPW patients are inconsistent or contradictory.</AbstractText>We included 1007 patient (pts) (mean age 35 years; 45% female) with an accessory pathway (AP) referred for non pharmacological treatment. Group 1 consisted of 56 pts (42M, aged 34 ± 15 yrs) with an AP and documented VF and Group 2-951 pts (513M, aged 35 ± 15 yrs) with an AP and without VF. Univariate predictors of VF were: overt pre-excitation, male gender, multiple AP, large AP. Multivariate predictors were: overt pre-excitation, male gender and MAP. The mean shortest pre-excited RR interval during AF was significantly shorter in Group 1: 205 ± 27 vs. 243 ± 64, P=0.019. VF as an end point of the first arrhythmia episode (AVRT or AF) was observed in 20 pts (15M, 5F). Primary VF (no documented arrhythmia prior to aborted SCD) occurred in 16 pts (13M, 3F). The mean age of primary VF pts was significantly lower than of pts with history of AVRT or AVRT and/or AF (24.5 vs. 36.5 vs. 38 yrs., P<0.005 and P=0.002, respectively). Age at VF occurrence shows a bi-modal distribution with peak occurrences in the 2-nd/3-rd and 5-th decades.</AbstractText>In patients with an accessory pathway, overt pre-excitation, male gender and multiple AP constitute independent risk factors of VF episodes. Young patients in the 2-nd/3-rd and older patients in the 5-th decade might be at higher risk of VF occurrence.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,367 | Electrophysiological determinants of arrhythmic susceptibility upon endocardial and epicardial pacing in guinea-pig heart. | Endocardial pacing instituted to treat symptomatic bradycardia may nevertheless promote tachyarrhythmia in some pacemaker-implanted patients. We sought to determine the contributing electrophysiological mechanisms.</AbstractText>Left ventricular (LV) monophasic action potential duration (APD(90)) and effective refractory periods were determined in perfused guinea-pig hearts along with volume-conducted ECG recordings during epicardial and endocardial stimulations.</AbstractText>Consistent with electrotonic modulation of repolarization, APD(90) at a given (either epicardial or endocardial) recording site tended to be longer while pacing from the ipsilateral LV site as compared to stimulations applied at the opposite side of ventricular wall. As a result, the intrinsic transmural repolarization gradient was amplified during endocardial pacing while being significantly reduced upon epicardial stimulations. The maximum slope of APD(90) restitution was greater upon endocardial than epicardial pacing. The excitability was found to recur at earlier repolarization time point at endocardium than epicardium, thereby contributing to increased endocardial critical intervals for re-excitation. Premature extrasystolic beats could have been elicited at shorter coupling stimulation intervals and propagated with greater transmural conduction delay upon endocardial than epicardial stimulations. Endocardial site exhibited lower ventricular fibrillation thresholds and greater inducibility of tachyarrhythmia upon extrasystolic stimulations as compared to epicardium.</AbstractText>Arrhythmic susceptibility in guinea-pig heart is greater during endocardial than epicardial pacing because of greater transmural APD(90) dispersion, steeper electrical restitution slopes, greater critical intervals for LV re-excitation and slower transmural conduction of the earliest premature ectopic beats. Further studies are warranted to determine whether these effects may contribute to proarrhythmia in paced human patients.</AbstractText>© 2012 The Author Acta Physiologica © 2012 Scandinavian Physiological Society.</CopyrightInformation> |
14,368 | Electrocardiographic left ventricular hypertrophy predicts arrhythmia and mortality in patients with ischemic cardiomyopathy. | The relatively low incidence of device-treated ventricular arrhythmias in patients with ischemic cardiomyopathy (ICM) who receive implantable cardioverter defibrillators (ICDs) for primary prevention makes improved risk stratification of ICM patients a priority. Although Cornell product (CP) ECG left ventricular hypertrophy (LVH) has been associated with increased mortality in hypertensive patients and population-based studies, whether CP LVH can improve risk stratification of high-risk ICM patients is unclear. The aim of this study is to examine if electrocardiographic LVH predicts mortality and incident ventricular arrhythmia in patients with ICM.</AbstractText>All-cause mortality was examined in 317 patients with ICM and a history of non-sustained ventricular tachycardia (VT) who underwent electrophysiology testing. Incident VT and ventricular fibrillation (VF) were assessed in ICD recipients (n = 186). ECG LVH was defined by CP criteria: [(R (aVL) + S (V3)) + 6 mm in women] × QRS duration >2,440 mm ms.</AbstractText>During 3 years of follow-up, mortality was 20% (64 of 317) and death or incident VT or VF occurred in 35% of ICD recipients. CP LVH was associated with significantly greater 3-year mortality (28% vs 15%, p = 0.015) and 3-year mortality or incident VT/VF in ICD patients (48% vs 35%, p = 0.011). In Cox multivariate models, CP LVH was an independent predictor of mortality in all patients (hazard ratio (HR) 1.81, 95% confidence interval (CI) 1.11-2.97, p = 0.020) and of the composite endpoint of mortality or incident ventricular arrhythmia in ICD patients (HR 1.82, 95% CI 1.12-3.00, p = 0.016).</AbstractText>ECG LVH using CP criteria may enhance risk stratification in high-risk patients with ICM.</AbstractText> |
14,369 | Pulmonary vein isolation to treat paroxysmal atrial fibrillation: conventional versus multi-electrode radiofrequency ablation. | For patients with symptomatic atrial fibrillation (AF), a curvilinear multi-electrode ablation (MEA) catheter has been reported to be successful to achieve pulmonary vein (PV) isolation. However, this approach has not been compared prospectively with conventional PV isolation (CPVI) using a standard circular mapping catheter and 3D electro-anatomic mapping. In this prospective non-randomized study, we compared the efficacy of these two techniques.</AbstractText>Of 185 consecutive patients, age 54.6 ± 10.1 years, with symptomatic paroxysmal AF (PAF), 96 patients underwent PV isolation by CPVI and 89 patients underwent MEA to isolate the PVs. CPVI was performed by encircling the left- and right-sided PVs. During MEA, the PV ablation catheter (Medtronic, USA) was used to isolate PVs with duty-cycled radiofrequency energy.</AbstractText>The mean procedure time was 171.73 ± 52.87 min for CPVI and 133.25 ± 37.99 min for MEA, respectively (P < 0.001). The mean fluoroscopy time was 31.07 ± 14.97 for CPVI and 30.07 ± 11.45 min for MEA (P = 0.651). At 12 months, 80% of patients who underwent CPVI and 82% of patients who underwent MEA were free of symptomatic PAF off antiarrhythmic drug therapy (P = 0.989). Among the variables of age, gender, duration and frequency of PAF, left ventricular ejection fraction, left atrial size, structural heart disease, and the ablation technique, only an increased left atrial size was an independent predictor of recurrent PAF. Left atrial flutter occurred after CPVI in two patients and after MEA ablation in three patients.</AbstractText>In patients undergoing catheter ablation for PAF, MEA and CPVI proved equally efficacious.</AbstractText> |
14,370 | Early mitral valve repair versus watchful waiting in patients with severe asymptomatic organic mitral regurgitation; rationale and design of the Dutch AMR trial, a multicenter, randomised trial. | Asymptomatic severe mitral valve (MV) regurgitation with preserved left ventricular function is a challenging clinical entity as data on the recommended treatment strategy for these patients are scarce and conflicting. For asymptomatic patients, no randomised trial has been performed for objectivising the best treatment strategy.</AbstractText>The Dutch AMR (Asymptomatic Mitral Regurgitation) trial is a multicenter, prospective, randomised trial comparing early MV repair versus watchful waiting in asymptomatic patients with severe organic MV regurgitation. A total of 250 asymptomatic patients (18-70 years) with preserved left ventricular function will be included. Intervention will be either watchful waiting or MV surgery. Follow-up will be 5 years. Primary outcome measures are all-cause mortality and a composite endpoint of cardiovascular mortality, congestive heart failure, and hospitalisation for non-fatal cardiovascular and cerebrovascular events. Secondary outcome measures are total costs, cost-effectiveness, quality of life, echocardiographic and cardiac magnetic resonance parameters, exercise tests, asymptomatic atrial fibrillation and brain natriuretic peptide levels. Additionally, the complication rate in the surgery group and rate of surgery in the watchful waiting group will be determined.</AbstractText>The Dutch AMR trial will be the first multicenter randomised trial on this topic. We anticipate that the results of this study are highly needed to elucidate the best treatment strategy and that this may prove to be an international landmark study.</AbstractText> |
14,371 | [Baby with respiratory problems and cardiac arrest]. | A ten-month-old girl was admitted to hospital with respiratory and gastrointestinal symptoms. Her condition deteriorated the following day, and she presented with symptoms of inspiratory stridor, facial palsy and ventricular fibrillation. She was resuscitated and intubated, and a normal spinal puncture was performed. Further investigation revealed areflexia, general hypotonia and reduced ejection fraction. Neurophysiological investigation showed long F-response, and renewed cerebrospinal fluid testing showed albuminocytologic dissociation, both typical signs of acute inflammatory demyelinating polyneuropathy (AIDP). Antitoxin was administered to the baby on suspicion of botulism, but immunological and microbiological testing ruled out infectious aetiology. She showed rapid improvement after i.v. immunoglobulin therapy, and was completely restituted/recovered 6 months after the incident. |
14,372 | Shen-fu injection attenuates postresuscitation lung injury in a porcine model of cardiac arrest. | To investigate the effects of Shen-Fu injection (SFI) on postresuscitation lung injury in a porcine model of cardiac arrest.</AbstractText>Twenty-four anaesthetised male Landrace pigs were subjected to 4 min of untreated ventricular fibrillation (VF), followed by standard cardiopulmonary resuscitation. Sixteen successfully resuscitated pigs were randomised into two groups (eight pigs per group); one group received an SFI infusion and the other group received a normal saline infusion, at an infusion rate of 0.24 mg/min from 15 min after the return of spontaneous circulation (ROSC) until 6h after ROSC.</AbstractText>Oxygenation index, respiratory index, oxygen delivery, oxygen consumption, oxygen extraction, dynamic lung compliance, airway resistance, external vascular lung water index, and pulmonary vascular permeability index at 15 min, 30 min, 1h, 2h, 4h, and 6h after ROSC were all worse than baseline in the saline group, and were all better in the SFI group than in the saline group. The pulmonary protective effects of SFI were further confirmed by histopathological and ultrastructural observations of lung tissue. SFI infusion resulted in lower apoptosis index, caspase-3 protein expression, and malondialdehyde content of lung tissue after ROSC, and increased Bcl-2 protein expression and superoxide dismutase, Na+ -K+ -ATPase, and Ca2+ -ATPase activity compared with the saline group.</AbstractText>Shen-Fu injection can attenuate postresuscitation lung injury through suppression of lung cell apoptosis and improvement of energy metabolism and antioxidant capacity.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,373 | Analysis of amplitude spectral area and slope to predict defibrillation in out of hospital cardiac arrest due to ventricular fibrillation (VF) according to VF type: recurrent versus shock-resistant. | In out-of-hospital cardiac arrest (OHCA) due to ventricular fibrillation (VF), VF may recur during resuscitation (recurrent VF) or fail to defibrillate (shock-resistant VF). While retrospective studies have suggested that amplitude spectral area (AMSA) and slope predict defibrillation, it is unknown whether the predictive power is influenced by VF type. We hypothesized that in witnessed OHCA with initial rhythm of VF that the utility for AMSA and slope to predict defibrillation would differ between shock-resistant and recurrent VF.</AbstractText>AMSA and slope were measured immediately prior to each shock. For second or later shocks, VF was classified as recurrent or shock-resistant. Cardiac arrest was classified according to whether the majority of shocks were for recurrent VF or shock-resistant VF.</AbstractText>44 patients received 98 shocks for recurrent VF and 96 shocks for shock-resistant VF; 24 patients achieved ROSC in the field. AMSA and slope were higher in recurrent VF compared to shock-resistant VF (AMSA: 28.8±13.1 vs 15.2±8.6 mVHz, P<0.001, and slope: 2.9±1.4 vs 1.4±1.0 mVs(-1), P=0.001). Recurrent VF was more likely to defibrillate than shock-resistant VF (P<0.001). AMSA and slope predicted defibrillation in shock-resistant VF (P<0.001 for both AMSA and slope) but not in recurrent VF. Recurrent VF predominated in 79% of patients that achieved ROSC compared to 55% that did not (P=0.10).</AbstractText>In witnessed OHCA with VF as initial rhythm, recurrent VF is associated with higher values of AMSA and slope and is likely to re-defibrillate. However, when VF is shock-resistant, AMSA and slope are highly predictive of defibrillation.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,374 | Increasing hospital volume is not associated with improved survival in out of hospital cardiac arrest of cardiac etiology. | Resuscitation centers may improve patient outcomes by achieving sufficient experience in post-resuscitation care. We analyzed the relationship between survival and hospital volume among patients suffering out-of-hospital cardiac arrest (OHCA).</AbstractText>This prospective cohort investigation collected data from the Cardiac Arrest Registry to Enhance Survival database from 10/1/05 to 12/31/09. Primary outcome was survival to discharge. Hospital characteristics were obtained via 2005 American Hospital Association Survey. A hospital's use of hypothermia was obtained via direct survey. To adjust for hospital- and patient-level variation, multilevel, hierarchical logistic regression was performed. Hospital volume was modeled as a categorical (OHCA/year≤10, 11-39, ≥40) variable. A stratified analysis evaluating those with ventricular fibrillation or pulseless ventricular tachycardia (VF/VT) was also performed.</AbstractText>The cohort included 4125 patients transported by EMS to 155 hospitals in 16 states. Overall survival to hospital discharge was 35% among those admitted to the hospital. Individual hospital rates of survival varied widely (0-100%). Unadjusted survival did not differ between the 3 hospital groups (36% for ≤10 OHCA/year, 35% for 11-39, and 36% for ≥40; p=0.75). After multilevel adjustment, differences in survival across the groups were not statistically significant. Compared to patients at hospitals with ≤10 OHCA/year, adjusted OR for survival was 1.04 (CI(95) 0.83-1.28) among 11-39 annual volume and 0.97 (CI(95) 0.73-1.30) among the ≥40 volume hospitals. Among patients presenting with VF/VT, no difference in survival was identified between the hospital groups.</AbstractText>Survival varied substantially across hospitals. However, hospital OHCA volume was not associated with likelihood of survival. Additional efforts are required to determine what hospital characteristics might account for the variability observed in OHCA hospital outcomes.</AbstractText>Published by Elsevier Ireland Ltd.</CopyrightInformation> |
14,375 | Modulation of spiral-wave dynamics and spontaneous activity in a fibroblast/myocyte heterocellular tissue--a computational study. | Fibroblasts make for the most common nonmyocyte cells in the human heart and are known to play a role in structural remodeling caused by aging and various pathological states, which can eventually lead to cardiac arrhythmias and fibrillation. Gap junction formed between fibroblasts and myocytes have been recently described and were shown to alter the cardiac electrical parameters, such as action potential duration and conduction velocity, in various manners. In this study, we employed computational modeling to examine the effects of fibroblast-myocyte coupling and ratio on automaticity and electrical wave conduction during reentrant activity, with specific emphasis on dynamic phenomena and stability. Our results show that fibroblast density and coupling impact wave frequency in a biphasic way, first increasing wave frequency and then decreasing it. This can be explained by the dual role of the fibroblast cell as a current sink or a current source, depending on the coupled myocytes intracellular potential. We have also demonstrated that wave stability as manifested by the spiral-wave tip velocity and reentrant activity lifespan depends on fibroblast-myocyte coupling and ratio in a complex way. Finally, our study describes the required conditions in which spontaneous activity can occur, as a result of the fibroblasts depolarizing the myocytes' resting potential sufficiently to induce rhythmic pulses without any stimulation applied. |
14,376 | Long-term follow-up in patients with arrhythmogenic right ventricular cardiomyopathy. | Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a major cause of sudden cardiac death due to tachyarrhythmias. The purpose of this study was to investigate the long-term prognosis in patients with ARVC and the incidence of rapid ventricular arrhythmias during follow-up.</AbstractText>Thirty ARVC patients (19 male, 63.3%, mean age 48 ± 15 years) fulfilling modified Task Force criteria 2010 were included. Of them, 13 patients (43.3%) received implantable cardioverter-defibrillator (ICD) implantation. Rapid ventricular arrhythmia was defined as electrical storm or the occurrence of ventricular tachycardia (VT) or ventricular fibrillation (VF) with a cycle length of 240 ms or less that necessitate shock delivery to 2 or more times within a 24-hour period.</AbstractText>With a mean follow-up of 68 ± 10 months, 6 patients (20%) with ICD implantation had recurrent rapid VT/VF. One (3.3%) of them died of multiple shocks and SCD, and 5 (16.7%) had multiple ICD therapies due to VT/VF and electrical storm. The interval between the diagnosis of ARVC and occurrence of rapid VT/VF was 13.4 ± 4.9 months. Most (5/6, 83.3%) events of recurrent rapid VT/VF occurred within 2 years. Ablated patients who did not receive an ICD implant were totally free of rapid VT/VF.</AbstractText>For patients with ARVC, long-term prognosis is favorable. During a long-term follow-up, patients meeting the criteria for ICD implantation have a higher rate of rapid and potentially life-threatening arrhythmias. However, early and clustered recurrence of rapid VT/VF in patients with an ICD is common, whereas late occurrence of rapid VT/VF is very rare.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,377 | Circadian and seasonal variations of ventricular tachyarrhythmias in patients with early repolarization syndrome and Brugada syndrome: analysis of patients with implantable cardioverter defibrillator. | The circadian and seasonal patterns of ventricular tachyarrhythmia (VTA) in patients with early repolarization syndrome (ERS) have not been determined. We compared the timing of VTAs in patients with ERS and Brugada syndrome (BS).</AbstractText>We enrolled patients with ERS (n = 14) and BS (n = 53) who underwent implantable cardioverter defibrillator (ICD) implantation. The timing of VTAs, including cardiac arrest and appropriate shocks, was determined. During follow up of 6.4 ± 3.6 years in the ERS group and 5.0 ± 3.3 years in the BS group, 5 of 14 (36%) ERS and 10 of 53 (19%) BS patients experienced appropriate shocks (P = 0.37). Cardiac arrest showed a trend of nocturnal distribution peaking from midnight to early morning (P = 0.14 in ERS, P = 0.16 in BS). Circadian distribution of appropriate shocks showed a significant nocturnal peak in patients with ERS (P < 0.0001) but a trend toward a nocturnal peak in patients with BS (P = 0.08). There were no seasonal differences in cardiac arrest in patients with ERS and BS. However, patients with ERS showed a seasonal peak in appropriate shocks from spring to summer (P < 0.0001). There was no significant seasonal peak in patients with BS. The timing of VTAs (cardiac arrest plus appropriate shock) showed significant nocturnal distributions in patients with ERS and BS (P < 0.01, respectively). A significant clustering of VTAs was noted from spring to summer (P < 0.01) in patients with ERS, but not in patients with BS (P = 0.42).</AbstractText>Incidence of VTAs showed marked circadian variations with night-time peaks in patients with ERS and BS.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,378 | Complication-associated mortality following trauma: a population-based observational study. | Complications are common in the care of trauma patients and contribute to morbidity, mortality, and cost. However, no comprehensive list of surgical complications is widely accepted.</AbstractText>To create an empirical list of complications based on the International Classification of Diseases, Ninth Revision (ICD-9) lexicon and estimate the contribution of these complications to mortality.</AbstractText>Retrospective database analysis.</AbstractText>Office of Statewide Health Planning and Development data set.</AbstractText>The Office of Statewide Health Planning and Development provided information on 409,393 patients admitted to 1 of 159 California hospitals between 2004 and 2008. We defined a complication to be any ICD-9- coded condition that accrued after hospital admission and significantly increased mortality.</AbstractText>Odds of mortality for individual complications and number of excess deaths due to individual complications based on attributable risk fractions.</AbstractText>Eighty-two different ICD-9 codes contributed significantly to mortality as complications. Odds ratios ranged from 1.02 (hyperosmolarity) to 46.1 (ventricular fibrillation). There were a total of 175,299 complications (range, 0-14; average 0.4/patient). Twenty-four percent of patients had at least 1 complication. Mortality increased with the number of complications; each additional complication increased mortality by 8%. Absent any complications, there would have been 7292 fewer deaths, a 64% reduction in overall mortality.</AbstractText>Most complication-related mortality is due to 25 individual complications. Eliminating all complications might prevent two-thirds of deaths, but because many complications are not preventable, this figure is the upper bound on possible mortality reduction. Hospitals vary in their proportions of deaths due to complications, and thus, efforts to prevent complications might improve survival at some hospitals.</AbstractText> |
14,379 | [Sleep-disordered breathing and cardiac arrhythmias]. | Sleep-disordered breathing (SDB) is an important comorbidity in patients with cardiac arrhythmias. Previous studies confirmed associations between supraventricular and ventricular arrhythmias and SDB. In heart failure patients, SDB was also found independently associated with a shorter event-free survival to the occurrence of malignant ventricular arrhythmias requiring appropriate cardioverter-defibrillator therapy. In obstructive sleep apnea, repetitive hypoxemia, mechanical stress (wall tension), arousals from sleep, and activation of the sympathetic nervous system promote cardiac arrhythmias. Pathophysiological concepts for the link between Cheyne-Stokes respiration and malignant arrhythmias are not fully understood and require further research. In addition, large-scale, randomized, controlled trials are awaited to prove whether adequate treatment of SDB is associated with a risk reduction for the occurrence of arrhythmias, in general, and malignant ventricular arrhythmias, in particular, in these patients. |
14,380 | Imaging arrhythmogenic calcium signaling in intact hearts. | Protein complex of the cardiac junctional sarcoplasmic reticulum (SR) membrane formed by type 2 ryanodine receptor, junction, triadin, and calsequestrin is responsible for controlling SR calcium (Ca) release. Increased intracellular calcium (Ca(i)) activates the electrogenic sodium-Ca exchanger current, which is known to be important in afterdepolarization and triggered activities (TAs). Using optical-mapping techniques, it is possible to simultaneously map membrane potential (V (m)) and Ca(i) transient in Langendorff-perfused rabbit ventricles to better define the mechanisms by which V (m) and Ca(i) interactions cause early afterdepolarizations (EADs). Phase 3 EAD is dependent on heterogeneously prolonged action potential duration (APD). Electrotonic currents that flow between a persistently depolarized region and its recovered neighbors underlies the mechanisms of phase 3 EADs and TAs. In contrast, "late phase-3 EAD" is induced by APD shortening, not APD prolongation. In failing ventricles, upregulation of apamin-sensitive Ca-activated potassium (K) channels (I(KAS)) causes APD shortening after fibrillation-defibrillation episodes. Shortened APD in the presence of large Ca(i) transients generates late-phase 3 EADs and recurrent spontaneous ventricular fibrillation. The latter findings suggest that I (KAS) may be a novel antiarrhythmic targets in patients with heart failure and electrical storms. |
14,381 | A 10min "no-touch" time - is it enough in DCD? A DCD animal study. | Donation after cardiac death (DCD) is under investigation because of the lack of human donor organs. Required times of cardiac arrest vary between 75s and 27min until the declaration of the patients' death worldwide. The aim of this study was to investigate brain death in pigs after different times of cardiac arrest with subsequent cardiopulmonary resuscitation (CPR) as a DCD paradigm. DCD was simulated in 20 pigs after direct electrical induction of ventricular fibrillation. The "no-touch" time varied from 2min up to 10min; then 30min of CPR were performed. Brain death was determined by established clinical and electrophysiological criteria. In all animals with cardiac arrest of at least 6min, a persistent loss of brainstem reflexes and no reappearance of bioelectric brain activity occurred. Reappearance of EEG activity was found until 4.5min of cardiac arrest and subsequent CPR. Brainstem reflexes were detectable until 5min of cardiac arrest and subsequent CPR. According to our experiments, the suggestion of 10min of cardiac arrest being equivalent to brain death exceeds the minimum time after which clinical and electrophysiological criteria of brain death are fulfilled. Therefore shorter "no-touch" times might be ethically acceptable to reduce warm ischemia time. |
14,382 | Management-oriented classification of mitral valve regurgitation. | Mitral regurgitation (MR) has previously been classified into rheumatic, primary, and secondary MR according to the underlying disease process. Carpentier's/Duran functional classifications are apt in describing the mechanism(s) of MR. Modern management of MR, however, depends primarily on the severity of MR, status of the left ventricular function, and the presence or absence of symptoms, hence the need for a management-oriented classification of MR. In this paper we describe a classification of MR into 4 phases according to LV function: phase I = MR with normal left ventricle, phase II = MR with normal ejection fraction (EF) and indirect signs of LV dysfunction such as pulmonary hypertension and/or recent onset atrial fibrillation, phase III = EF ≥ 30%-< 50% and/or mild to moderate LV dilatation (ESID 40-54 mm), and phase IV = EF < 30% and/or severe LV dilatation (ESDID ≥ 55 mm). Each phase is further subdivided into three stages: stage "A" with an effective regurgitant orifice (ERO) < 20 mm, stage "B" with an ERO = 20-39 mm, and stage "C" with an ERO ≥ 40 mm. Evidence-based indications and outcome of intervention for MR will also be discussed. |
14,383 | Prognostic implications of tricuspid regurgitation in patients with severe aortic regurgitation: results from a cohort of 756 patients. | Tricuspid regurgitation (TR) is common, but neglected. We evaluated the prognostic implications of TR in a cohort of 756 patients with severe aortic regurgitation (AR). A cohort of 756 patients with AR was identified from our echocardiographic database. Chart reviews were performed. Survival as a function of TR severity was analysed. Of the 756 patients with severe AR, 264 (35%) had ≥ 2+ TR. Univariate correlates of TR were older age (P < 0.0001), female gender (P < 0.0001), lower left ventricular ejection fraction (P < 0.0001), atrial fibrillation (P < 0.0001), presence of a pacemaker (P < 0.0001), higher PASP (P < 0.0001), presence of 3 or 4+ mitral regurgitation (P < 0.0001) and not being on a beta-blocker (P < 0.0001) or statins (P = 0.007). After adjusting for group differences, ≥ 2+ TR was an independent predictor of higher mortality (RR 1.47, P = 0.005). Aortic valve replacement (AVR) was independently associated with improved survival in patients with ≥ 2+ TR. (RR 0.46, 95% CI 0.36-0.60, P < 0.0001). In conclusion, in severe AR patients, ≥ 2+ TR is independently associated with a higher mortality. The performance of AVR in these patients with ≥ 2+ TR is associated with a survival benefit. Development of ≥ 2+ TR in these patients is a marker of decompensation and should serve as an indication for AVR. |
14,384 | N-3 polyunsaturated fatty acid supplementation does not reduce vulnerability to atrial fibrillation in remodeling atria. | Prophylactic supplementation with omega-3 polyunsaturated fatty acids (PUFAs) reduce vulnerability to atrial fibrillation (AF). The effect of PUFAs given after cardiac injury has occurred is unknown.</AbstractText>To investigate using a model of pacing-induced cardiac injury, the time course of development of injury and whether it was altered by postinjury PUFAs.</AbstractText>Sixty-five dogs were randomized to undergo simultaneous atrial and ventricular pacing (SAVP, 220 beats/min) for 0, 2, 7, or 14 days. Twenty-two dogs received PUFAs (850 mg/d) either prophylactically or after some pacing had occurred (postinjury). Electrophysiologic and echocardiographic measurements were taken at baseline and sacrifice. Atrial tissue samples were collected at sacrifice for histologic and molecular analyses.</AbstractText>With no PUFAs, the inducibility of AF increased with pacing duration (P < .001). Postinjury PUFAs (started after 7 days of pacing) did not reduce the inducibility of AF after 14 days of pacing (9.3% ± 8.8% no PUFAs vs 9.7% ± 9.9% postinjury PUFAs; P = .91). Atrial myocyte size and fibrosis increased with pacing duration (P < .05). Postinjury PUFAs did not significantly attenuate the cell size increase after 14 days of pacing (no PUFAs 38% ± 30% vs postinjury PUFAs 19% ± 28%; P = .11). Similarly, postinjury PUFAs did not attenuate the increase in fibrosis after 14 days of pacing (no PUFAs 66% ± 51% vs postinjury PUFAs 63% ± 76%; P = .90).</AbstractText>PUFA supplementation begun after cardiac injury has already occurred does not reduce atrial structural remodeling or vulnerability to AF.</AbstractText>Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,385 | Various patterns of intracardiac electrogram T-wave alternans prior to ventricular tachyarrhythmias in implantable cardioverter-defibrillator patients. | It has been reported that intracardiac electrogram T-wave alternans (IE-TWA) is greater prior to spontaneous ventricular tachyarrhythmia (VTA) than for baseline recordings.</AbstractText>To investigate IE-TWA just prior to VTA episodes and at baseline and compare these with microvolt TWA (M-TWA) measured during exercise.</AbstractText>We analyzed right ventricular ring-can electrogram recordings just prior to VTA episodes and compared T-wave pattern and degree of variation to baseline recordings from 3 patients (2 with idiopathic ventricular fibrillation and 1 with hypertrophic cardiomyopathy) who were enrolled in the Japan Intracardiac Electrogram TWA Study of ICD Recipients. In a stable state, we measured the M-TWA of the surface electrocardiogram during treadmill exercise in these 3 patients.</AbstractText>We found 3 patterns of IE-TWA among these 3 patients with implantable cardioverter-defibrillator immediately prior to spontaneous VTAs. Case 1 had AB pattern of IE-TWA, case 2 ABC pattern, and case 3 nonspecific pattern but great T-wave amplitude variations. These IE-TWA amplitudes and the distribution of T-amplitude difference were greater than at baseline. Case 1 had a positive outcome in regard to the M-TWA determination, whereas cases 2 and 3 did not.</AbstractText>We indicate different patterns of IE-TWA prior to spontaneous VTAs. The phenomena of IE-TWA correspond to outcomes of M-TWA measured during exercise in the surface electrocardiogram.</AbstractText>Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,386 | A suddenly lethal accessory pathway. | A 17-year-old girl was diagnosed with an asymptomatic Wolff-Parkinson-White pattern just before a major orthopedic operation. Three months after the surgery, she developed ventricular fibrillation-being the first manifestation of her Wolff-Parkinson-White syndrome. The patient was successfully reanimated. radiofrequency ablation permanently interrupted conduction over a right posteroseptal accessory pathway. |
14,387 | Role of AV nodal ablation in cardiac resynchronization in patients with coexistent atrial fibrillation and heart failure a systematic review. | The aim of this study was to systematically review the medical literature to evaluate the impact of AV nodal ablation in patients with heart failure and coexistent atrial fibrillation (AF) receiving cardiac resynchronization therapy (CRT).</AbstractText>CRT has a substantial evidence base in patients in sinus rhythm with significant systolic dysfunction, symptomatic heart failure, and prolonged QRS duration. The role of CRT is less well established in AF patients with coexistent heart failure. AV nodal ablation has recently been suggested to improve outcomes in this group.</AbstractText>Electronic databases and reference lists through September 15, 2010, were searched. Two reviewers independently evaluated citation titles, abstracts, and articles. Studies reporting the outcomes after AV nodal ablation in patients with AF undergoing CRT for symptomatic heart failure and left ventricular dyssynchrony were selected. Data were extracted from 6 studies, including 768 CRT-AF patients, composed of 339 patients who underwent AV nodal ablation and 429 treated with medical therapy aimed at rate control alone.</AbstractText>AV nodal ablation in CRT-AF patients was associated with significant reductions in all-cause mortality (risk ratio: 0.42 [95% confidence interval: 0.26 to 0.68]), cardiovascular mortality (risk ratio: 0.44 [95% confidence interval: 0.24 to 0.81]), and improvement in mean New York Heart Association functional class (risk ratio: -0.52 [95% confidence interval: -0.87 to -0.17]).</AbstractText>AV nodal ablation was associated with a substantial reduction in all-cause mortality and cardiovascular mortality and with improvements in New York Heart Association functional class compared with medical therapy in CRT-AF patients. Randomized controlled trials are warranted to confirm the efficacy and safety of AV nodal ablation in this patient population.</AbstractText>© 2012 American College of Cardiology Foundation.</CopyrightInformation> |
14,388 | Effect of a pacing mode preserving spontaneous AV conduction on ventricular pacing burden and atrial arrhythmias. | Using dual-chamber pacemakers with new algorithms: Manage Ventricular Pacing (MVP™), minimizes unnecessary ventricular pacing (VP). This function operates in AAI/R mode with backup VP during AV block.</AbstractText>The aim of "Generation MVP" study was to assess the VP burden and atrial arrhythmias (AA) burden according to indication of pacing and MVP™ function programming of AdaptaDR implantable pacemaker (Medtronic Inc., Minneapolis, MN, USA).</AbstractText>The multicenter observational "Generation MVP" study included 220 patients aged 75.9 ± 11 years (men = 52%) implanted for sinus node dysfunction (SND; n = 115) or atrio-ventricular block (AVB; n = 105). Programming MVP function has been left to the physician's discretion. Percentage of VP and AA burden (percentage of time spent in AA) stored in memories were assessed at 2 and 10 months.</AbstractText>220 patients were followed at 2 months (174 MVP [On], 46 MVP [off]) and at 10 months (165 MVP [On], 55 MVP [off]). Median percentage of VP is significantly lower when MVP is programmed [On] versus [off] at 2 and 10 months follow-up for SND and AVB indications of pacing (P < 0.001). Finally, programming MVP function is performed at middle term (10 months) for 84% of patients with SND and 65% of patients with AVB: median percentage of VP is as low as 0.6% for patients with SND and 12% for patients with AVB versus 95% for SND and 99% for AVB when MVP function is programmed [off](P < 0.001). Median AA burden was significantly lower when MVP function was programmed [On] versus [off] at 2 months (8.7% vs 28%; P < 0.001) and 10 months (1% vs 22%; P < 0.001).</AbstractText>In this study programming MVP function decreases percentage of VP at 2 and 10 months for patients paced for SND or AVB. Moreover median AA burden is reduced when MVP function was programmed [On] vs [off] at two follow-ups.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,389 | A rare case of acute diffuse alveolar hemorrhage following initiation of amiodarone: a case report. | Amiodarone is effective for treating ventricular and supraventricular tachyarrhythmias, despite potential side effects which can include injury to the liver, thyroid, cornea, skin, and neuromuscular system. Acute lung toxicity is a known but rare side effect of amiodarone use, most commonly taking the form of an acute or subacute interstitial pneumonitis. Diffuse alveolar hemorrhage is a rare reaction, with few case reports documented in the literature since amiodarone became widely used in the early 1980s. We report the case of a patient who developed severe respiratory failure and diffuse alveolar infiltrates within 72 hours of initiating amiodarone therapy. Postmortem lung histology confirmed the diagnosis of diffuse alveolar hemorrhage. The case presentation and proposed mechanisms of action will be reviewed here. |
14,390 | Long-term follow-up of patients with cardiac sarcoidosis and implantable cardioverter-defibrillators. | Ventricular tachyarrhythmias are an important cause of morbidity and mortality in cardiac sarcoidosis. To date, the prevalence and incidence of ventricular tachycardia/ventricular fibrillation (VT/VF) in this population remain unknown.</AbstractText>To determine the prevalence and incidence of ventricular tachyarrhythmias in patients with cardiac sarcoidosis and to identify the clinical attributes associated with appropriate implantable cardioverter-defibrillator (ICD) therapies.</AbstractText>We studied 45 patients with ICDs, biopsy-proven systemic sarcoidosis, and cardiac involvement, as evidenced by histopathology, cardiac magnetic resonance imaging, and/or (18)F-fluoro-2-deoxyglucose-positron emission tomography imaging. Device logs and medical records were retrospectively reviewed.</AbstractText>Appropriate ICD therapies for VT/VF were observed in 37.8% of the patients with an incidence of 15% per year. Inappropriate ICD therapies occurred in 13.3% of the patients. Longer ICD follow-up (4.5 ± 3.1 years vs 1.5 ± 1.5 years; P = .001), depressed left ventricular ejection fraction (35.5% ± 15.5% vs 50.9% ± 15.5%; P = .002), and complete heart block (47.1% vs 17.9%; P = .048) were associated with appropriate ICD therapy. While there was no significant difference in the total number of shocks/antitachycardia pacing-terminated events between primary (n = 29) and secondary (n = 16) prevention groups, there was a trend toward more events in the secondary prevention arm after 2 years.</AbstractText>Ventricular tachyarrhythmias requiring ICD therapy were common in patients with cardiac sarcoidosis, with an estimated incidence rate of 15% per year. Longer follow-up, left ventricular systolic dysfunction, and complete heart block were associated with VT/VF. Patients with primary prevention ICDs had high rates of appropriate ICD therapy but not as high as did secondary prevention patients. In the absence of reliable risk stratification techniques, consideration should be given to prophylactic ICD implantation in patients with cardiac sarcoidosis.</AbstractText>Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,391 | [Efficacy of sequential ablation of sinus atrial node fat pad and atrial ventricular node fat pad on inducibility of atrial fibrillation evoked by vagus trunk stimulation]. | To explore the efficacy of sequential ablation of epicardial fat pad on inducibility of atrial fibrillation (AF) evoked by stimulating vagus trunk.</AbstractText>Eighteen adult mongrel dogs were randomly divided into 2 groups (n = 9 each): Group A underwent pre-ablation of sinus-atrial node fad pad (SANFP) and subsequent ablation of atria-ventricular node fad pad (AVNFP). Group B underwent pre-ablation of AVNFP and subsequent ablation of SANFP. AF was induced by high-frequency electrical stimulation of bilateral vagus trunks. The AF inducibility and effective refractory period (ERP) changes during vagus trunk stimulation were examined before and after ablation in atria and pulmonary veins.</AbstractText>(1) AF could be induced by vagus trunk stimulation and the incidence was higher during right vagus trunk (RVG) stimulation than left vagus trunk (LVG) stimulation [(60.0 ± 0.0)% vs (18.4 ± 22.1)%]. (2) SANFP ablation significantly attenuated AF inducibility with LVG stimulation and RVG stimulation at 2 V (decreased 67.0% and 72.0%, respectively). Subsequent AVNFP ablation after SANFP ablation further reduced AF inducibility with LVG and RVG stimulation at 2 V (decreased 100.0% and 95.5%, respectively). (3) AVNFP ablation (decreased 95.7% and 96.3%, respectively) and subsequent SANFP ablation after AVNFP ablation (decreased 98.0% and 100.0%, respectively) significantly attenuated AF inducibility with LVG stimulation and RVG stimulation at 2V. (4) Vagal stimulation induced ERP shortening was significantly attenuated by isolated SANFP ablation or AVNFP. Subsequent AVNFP ablation after SANFP induced significant ERP shortening in right atrial site compared with isolated SANFP ablation. However, changes of ERP shortening were similar between AVNFP ablation and subsequent SANFP ablation after AVNFP ablation.</AbstractText>Epicardial fat pad ablation reduced the AF inducibility and prolonged ERP of atria and pulmonary veins during vagus trunk stimulation. AVNFP, as the "integration centers" modulating the vagal innervation to the atria, may be the more effective target of ablation for treating AF.</AbstractText> |
14,392 | [Efficacy of ibutilide for cardioversion of persistent atrial fibrillation during radiofrequency ablation]. | The aim of this study was to investigate the efficiency and safety of ibutilide for cardioversion of persistent atrial fibrillation (AF) during radiofrequency ablation.</AbstractText>Eighteen patients (16 males) with persistent atrial fibrillation were enrolled in this study. All patients underwent circumferential pulmonary vein ablation guided by a Carto three-dimensional mapping system. In addition, linear ablation at the top of the left atrium and the isthmus of mitral valves and complex fractionated atrial electrogram (CAFE) ablation were performed. All patients were still in either atrial fibrillation or atrial flutter after ablation, the patients were treated with 1 mg intravenous ibutilide injection within 10 minutes after unsuccessful ablation. Intravenous injection was stopped in case of sinus rhythm (SR) restoration or occurrence of severe adverse reactions such as ventricular tachycardia. Cardioversion rate within 30 min and adverse reactions within 4 h were observed. Patients were divided into either conversion group or non-conversion group according to whether AF was converted to sinus rhythm within 30 minutes after injection.</AbstractText>Eleven patients (61.11%) converted to SR after ibutilide injection. There were no significant differences in gender, age, body mass index, left atrium and left ventricular function between conversion group and non-conversion groups. The average conversion time was (13.80 ± 7.64) min, left atrium scar area ratio was significantly larger in non-conversion group (12.40 ± 11.03)% than in conversion group (5.12 ± 3.83)%, P < 0.05. Ibutilide significantly prolonged the average wavelength of the AF wave (171.8 ± 29.5) ms vs. (242.0 ± 40.0) ms at baseline, P < 0.01. The QT interval at 30 min after ibutilide injection (0.39 ± 0.21) s was significantly longer than before injection (0.51 ± 0.08) s, P < 0.05. There was no serious arrhythmias or other adverse reactions post ibutilide injection.</AbstractText>Ibutilide is highly effective and safe agent for cardioversion in patients underwent unsuccessful ablation. Left atrium scar area ratio is an important determinant for the conversion rate in this cohort.</AbstractText> |
14,393 | [Initial experience of transcatheter implantation with a new aortic valve in sheep]. | To evaluate the feasibility and short-term results of transcatheter aortic valve implantation (TAVI) using a new transcatheter valve.</AbstractText>Twenty healthy adult sheep received general anesthesia. Under the guidance of X-ray and transthoracic echocardiography (TTE), the new anti-calcification transcatheter valve was released from delivery system and implanted at the level of native aortic annulus via left common carotid artery. Position and function of the new anti-calcification transcatheter valve were evaluated by angiography and TTE immediately after intervention. Thirty day survival rate of animals was obtained.</AbstractText>New transcatheter valves were implanted in all sheep. Fifteen sheep (75%) survived up to 30 days and post-operative examination showed that the transcatheter valve was in optimal position without migration and mitral valve impingement. The native coronary artery was patent in these animals. There was a slight paravalvular leak in 5 sheep. Postoperative echocardiography showed reflux percentage was significantly increased (P < 0.05) compared pre-intervention. Effective orifice area, aortic systolic pressure, diastolic aortic pressure, mean aortic pressure, left ventricular systolic pressure, left ventricular end diastolic pressure and heart rate were similar between post and pre-intervention (all P < 0.05). Five sheep died after TAVI within 30 days, including one fatal ventricular fibrillation occurred immediately after releasing the transcatheter valve and another sheep died of acute myocardial infarction due to left main coronary artery occlusion evidenced by angiography. Two sheep died of severe mitral regurgitation at 8 and 12 hours post-operation and one died of infective endocarditis at 26 days after intervention.</AbstractText>Our favorable preliminary results showed that it was feasible to perform TAVI using the new transcatheter valve.</AbstractText> |
14,394 | Influence of the time on the prevalence of drug-related resuscitated sudden death during these past 20 years. | The use of drugs is the subject of numerous recommendations. The purpose of this study was to evaluate the prevalence of drug-related sudden deaths (SD) and the possible changes during these past 20 years.</AbstractText>271 patients, 205 men, 66 women aged from 12 to 88 years (mean 59 ± 15) were admitted after SD resuscitation outside the acute phase of myocardial infarction, 146 before 2000 (group I), 125 between 2000 and 2010 (group II). Complete check-up was performed.</AbstractText>Ischemic HD (41%) vs (37%), idiopathic dilated cardiomyopathy (12%) vs (11%), various HD (5%) vs (8%) were as frequent in groups I and II. Valvular HDs were more frequent in group I than II (12%) vs 6% (p<0.01). Abnormalities at ECG (preexcitation syndrome, conduction disturbance, atrial fibrillation or ion channel disorders) were less frequent in group I than II (8%) vs (18%) (p<0.02). Drug-facilitated or related SD's did not change in groups I and II: 54 patients presented a drug-related ventricular fibrillation or asystole, 16% in group I and 24% (NS) in group II. SD was caused by hypokalemia, QT interval increase or conduction disturbance. HD or abnormal ECG was present in 42 patients. Digoxin, diuretics, calcium inhibitors, betablockers, antiarrhythmic drugs alone or in association were mainly implicated.</AbstractText>Drug-related arrhythmias continue to explain or favour at least 20% of SDs. Despite numerous recommendations on the use of drugs, the prevalence of fatal events that may be attributed to a cardiovascular drug does not decrease between the years before 2000 and after 2000.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,395 | Intracoronary cardiosphere-derived cells for heart regeneration after myocardial infarction (CADUCEUS): a prospective, randomised phase 1 trial. | Cardiosphere-derived cells (CDCs) reduce scarring after myocardial infarction, increase viable myocardium, and boost cardiac function in preclinical models. We aimed to assess safety of such an approach in patients with left ventricular dysfunction after myocardial infarction.</AbstractText>In the prospective, randomised CArdiosphere-Derived aUtologous stem CElls to reverse ventricUlar dySfunction (CADUCEUS) trial, we enrolled patients 2-4 weeks after myocardial infarction (with left ventricular ejection fraction of 25-45%) at two medical centres in the USA. An independent data coordinating centre randomly allocated patients in a 2:1 ratio to receive CDCs or standard care. For patients assigned to receive CDCs, autologous cells grown from endomyocardial biopsy specimens were infused into the infarct-related artery 1·5-3 months after myocardial infarction. The primary endpoint was proportion of patients at 6 months who died due to ventricular tachycardia, ventricular fibrillation, or sudden unexpected death, or had myocardial infarction after cell infusion, new cardiac tumour formation on MRI, or a major adverse cardiac event (MACE; composite of death and hospital admission for heart failure or non-fatal recurrent myocardial infarction). We also assessed preliminary efficacy endpoints on MRI by 6 months. Data analysers were masked to group assignment. This study is registered with ClinicalTrials.gov, NCT00893360.</AbstractText>Between May 5, 2009, and Dec 16, 2010, we randomly allocated 31 eligible participants of whom 25 were included in a per-protocol analysis (17 to CDC group and eight to standard of care). Mean baseline left ventricular ejection fraction (LVEF) was 39% (SD 12) and scar occupied 24% (10) of left ventricular mass. Biopsy samples yielded prescribed cell doses within 36 days (SD 6). No complications were reported within 24 h of CDC infusion. By 6 months, no patients had died, developed cardiac tumours, or MACE in either group. Four patients (24%) in the CDC group had serious adverse events compared with one control (13%; p=1·00). Compared with controls at 6 months, MRI analysis of patients treated with CDCs showed reductions in scar mass (p=0·001), increases in viable heart mass (p=0·01) and regional contractility (p=0·02), and regional systolic wall thickening (p=0·015). However, changes in end-diastolic volume, end-systolic volume, and LVEF did not differ between groups by 6 months.</AbstractText>We show intracoronary infusion of autologous CDCs after myocardial infarction is safe, warranting the expansion of such therapy to phase 2 study. The unprecedented increases we noted in viable myocardium, which are consistent with therapeutic regeneration, merit further assessment of clinical outcomes.</AbstractText>US National Heart, Lung and Blood Institute and Cedars-Sinai Board of Governors Heart Stem Cell Center.</AbstractText>Copyright © 2012 Elsevier Ltd. All rights reserved.</CopyrightInformation> |
14,396 | A novel minimal invasive closed chest myocardial ischaemia reperfusion model in rhesus monkeys (Macaca mulatta): improved stability of cardiorespiratory parameters. | The aim of this study was to report the cardiorespiratory events observed during coronary artery occlusion and reperfusion in a minimally invasive closed chest myocardial occlusion-reperfusion model in rhesus monkeys. We hypothesized that a minimally invasive technique may lead to fewer cardiac arrhythmias and complications. Eight male rhesus macaques 10-15 kg and 10-15 years old were sedated with ketamine (2 mg/kg), midazolam (1.3 mg/kg), atropine (0.01 mg/kg) and buprenorphine 0.02 mg/kg intramuscularly. Etomidate 1-2 mg/kg was injected intravenously to allow tracheal intubation. Anaesthesia was maintained with isoflurane. Pulse oximetry, electrocardiogram (ECG), heart rate, mean arterial blood pressure (MAP), inspired isoflurane fractions (F(I)ISO) and core temperature were recorded every 10 min. The coronary artery occlusion was induced by a balloon-tipped catheter advanced via the femoral artery into the left anterior descending artery and inflated to completely occlude the vessel for 20-50 min (IT) before reperfusion. Sequences of elevated ST segment, QRS complex prolongation, ventricular premature complexes and ventricular fibrillation were observed with a lower incidence than previously described in the literature. IT was (min: 17; max: 50) min long. F(I)ISO was lower than the minimal alveolar concentration in these species. Hypotension (MAP < 70 mmHg) and hypothermia (T°C < 36°C) were observed in all macaques. This minimally invasive closed chest model was successful in providing better cardiorespiratory physiological parameters than reported in previous models. The benefit (achieving ischaemia) versus risk (lethal arrhythmia) of the duration of the coronary occlusion should be considered. |
14,397 | Profile of microvolt T-wave alternans testing in 1003 patients hospitalized with heart failure. | Observational studies in selected populations have suggested that microvolt T-wave alternans (MTWA) testing may identify patients with heart failure (HF) at risk of sudden cardiac death. The aims of this study were to investigate the utility of MTWA testing in an unselected population of patients with HF and to evaluate the clinical characteristics associated with the MTWA results.</AbstractText>A total of 1003 patients hospitalized with decompensated HF were enrolled. MTWA testing was planned 1 month post-discharge; 648 patients returned for MTWA testing. Mean age was 70.8 ± 10.6 years and 58% were male. Of these patients who returned, 318 (49%) were ineligible for MTWA testing due to atrial fibrillation (AF), pacemaker dependency, or physical inability to undertake the test. Of the MTWA tests, 100 (30%) were positive, 78 (24%) were negative, and 152 (46%) were indeterminate; 112/152 indeterminate tests (74%) occurred because of failure to achieve target heart rate (HR) due to chronotropic incompetence or physical limitations. There were differences in patient characteristics according to MTWA result. Independent predictors of a negative result included younger age and higher left ventricular ejection fraction (LVEF). Independent predictors of a positive result included higher HR during MTWA testing and lower LVEF. Independent predictors of an indeterminate result included older age and history of previous/paroxysmal AF.</AbstractText>Only half of patients with HF are eligible for MTWA testing and the most common result is an indeterminate test. Patients with positive and indeterminate tests have different clinical characteristics. MTWA treadmill testing is not widely applicable in typical HF patients and is unlikely to refine risk stratification for sudden death on a population level.</AbstractText> |
14,398 | Papaverine-induced polymorphic ventricular tachycardia in relation to QTU and giant T-U waves in four cases. | Papaverine is used for the evaluation of functional status of the coronary arteries but it may provoke severe ventricular tachyarrhythmias (VTAs). This study compared the clinical and ECG characteristic of patients with papaverine-induced VTAs.</AbstractText>The study involved 25 patients who underwent a fractional flow reserve (FFR) study. FFR was determined as the ratio of blood pressure at the distal and the proximal site of stenosis after intracoronary papaverine administration at 12 mg into the left and 8 mg into the right coronary artery. The QT and QTU intervals were measured manually in the limb leads and in the precordial leads, respectively and corrected by the R-R interval to obtain QTc and QTUc. The clinical and ECG data were compared between the patient groups with and without VTAs.</AbstractText>After papaverine administration into the left (20), right (3) or both coronary arteries (2), the RR interval shortened, but non-significantly however, the QT interval (and QTc) and the QTU interval (and QTUc) were significantly prolonged. VTAs developed in four women: torsade de pointes in 3 followed by ventricular fibrillation and ventricular premature beats in 1 patient. After papaverine administration, QTU and QTUc were more prolonged in women than men and in patients with VTAs compared to those without. Just prior to VTAs, giant T-U waves were observed.</AbstractText>Intracoronary papaverine was used to determine FFR which may induce VTAs. VTAs developed only in women and they were closely related to prolongation of the QTU intervals with prominent T-U waves.</AbstractText> |
14,399 | Dietary omega-3 fatty acids and susceptibility to ventricular fibrillation: lack of protection and a proarrhythmic effect. | Recent clinical studies that evaluated the effects of supplemental omega-3 polyunsaturated fatty acids (n-3 PUFAs) on sudden cardiac death have yielded conflicting results. Our aim was to clarify this issue using an established and clinical relevant canine model of sudden cardiac death.</AbstractText>Susceptibility to ventricular fibrillation (VF) was evaluated using a 2-minute left circumflex artery occlusion during the last minute of an exercise test in 76 dogs (from 2 independent studies) with healed myocardial infarctions (MI); 44 developed VF (susceptible, VF+), whereas 32 did not (resistant, VF-). These dogs were then randomly assigned to either placebo (1 g/d, corn oil; 15 VF+, 11 VF-) or n-3 PUFA (1-4 g/d, docosahexaenoic acid+eicosapentaenoic acid ethyl esters, 29 VF+, 21 VF-) groups. Seven sham (no-MI) dogs were also treated with n-3 PUFA (4 g/d). After treatment (3 months), the exercise+ischemia test was repeated. Dietary n-3 PUFAs produced significant (P<0.01) increases in red blood cell and left ventricular n-3 PUFA levels. Nine post-MI (5 placebo versus 4 n-3 PUFA) and 2 sham dogs died suddenly during the 3-month treatment period. The n-3 PUFA treatment failed to prevent arrhythmias in VF+ dogs (decreased in 27% placebo versus 24% n-3 PUFA, P=0.5646) but induced VT/VF in VF- animals (n-3 PUFA 33% versus placebo 0%, P=0.0442).</AbstractText>Despite large increases in cardiac tissue n-3 PUFA content, dietary n-3 PUFAs did not prevent ischemia-induced VF and actually increased arrhythmia susceptibility in both noninfarcted and low-risk post-MI dogs.</AbstractText> |
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