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10,400 | Ventricular arrhythmia storm in the era of implantable cardioverter-defibrillator. | In the era of widespread use of implantable cardioverter-defibrillators (ICDs) for both primary and secondary prevention of sudden cardiac death, a significant proportion of patients experience episodes of multiple ventricular tachycardia/fibrillation over a short period of time requiring device interventions. The episodes are termed ventricular arrhythmia (VA) or electrical storms. VA storm is a tragic experience for patients, with many psychological consequences. Current management for VA storms remains complex. Acutely, administration of β-blockers, amiodarone and sedation or intubation is generally required to suppress sympathetic tone. Interventional treatment includes catheter ablation and sympathetic blockade by left cardiac sympathetic denervation. Strategies to modify autonomic tone to suppress VAs are the rationale of various novel interventions that have been published in recent studies. All patients with VA storm should be considered for transfer to an experienced high-volume tertiary centre for evaluation and treatment to prevent further recurrence of VA storm. |
10,401 | Early surgical intervention or watchful waiting for the management of asymptomatic mitral regurgitation: a systematic review and meta-analysis. | Discordance between studies drives continued debate regarding the best management of asymptomatic severe mitral regurgitation (MR). The aim of the present study was to conduct a systematic review and meta-analysis of management plans for asymptomatic severe MR, and compare the effectiveness of a strategy of early surgery to watchful waiting.</AbstractText>A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies were excluded if they: (I) lacked a watchful waiting cohort; (II) included symptomatic patients; or (III) included etiologies other than degenerative mitral valve disease. The primary outcome of the study was all-cause mortality at 10 years. Secondary outcomes included operative mortality, repair rate, repeat mitral valve surgery, and development of new atrial fibrillation.</AbstractText>Five observational studies were eligible for review and three were included in the pooled analysis. In asymptomatic patients without class I triggers (symptoms or ventricular dysfunction), pooled analysis revealed a significant reduction in long-term mortality with an early surgery approach [hazard ratio (HR) =0.38; 95% confidence interval (CI): 0.21-0.71]. This survival benefit persisted in a sub-group analysis limited to patients without class II triggers (atrial fibrillation or pulmonary hypertension) [relative risk (RR) =0.85; 95% CI: 0.75-0.98]. Aggregate rates of operative mortality did not differ between treatment arms (0.7% vs. 0.7% for early surgery vs. watchful waiting). However, significantly higher repair rates were achieved in the early surgery cohorts (RR =1.10; 95% CI: 1.02-1.18).</AbstractText>Despite disagreement between individual studies, the present meta-analysis demonstrates that a strategy of early surgery may improve survival and increase the likelihood of mitral valve repair compared with watchful waiting. Early surgery may also benefit patients when instituted prior to the development of class II triggers.</AbstractText> |
10,402 | The subcutaneous implantable cardioverter and defibrillator: advantages, limitations and future directions. | The totally subcutaneous implantable cardioverter and defibrillator (S-ICD) represents the most innovative development in implantable cardioverter and defibrillator therapy in the last 15 years. Its development arose out of concern for the long-term complications of transvenous devices. Clinical trials have shown that it is a safe and effective device for patients at risk of sudden cardiac death. The lack of transvenous and intracardiac components makes it an attractive choice for young patients, those with limited vascular access and increased infectious risk. Despite these advantages, the current S-ICD system has limitations, including the inability to deliver cardiac pacing. Future programming and technologic advancements have the opportunity to dramatically improve the efficacy and broaden the patient population treated with the S-ICD. |
10,403 | Propofol-induced rhabdomyolysis: a case report. | To report a case of propofol-induced rhabdomyolysis. In this case, widespread myolysis was detected after induction of anesthesia.</AbstractText>A 54-year-old female patient was scheduled for a hysterectomy. Beginning shortly after the induction of anesthesia with propofol, several episodes of ventricular fibrillation occurred. Despite intensive care, the patient failed to recover. During most episodes of ventricular fibrillation, marked hyperthermia or hyperkalemia were not observed. Unexplained, widespread myolysis affecting both skeletal and cardiac muscle was observed at autopsy.</AbstractText>In this patient, the evidence for rhabdomyolysis is robust. Clinical characteristics are similar to those observed in propofol infusion syndrome. The absence of a body temperature over 40 °C precludes the possibility of malignant hyperthermia. Widespread rhabdomyolysis locations cannot be explained by precordial electric shocks. Propofol is the only drug used in this case that has been reported to induce rhabodomyolysis.</AbstractText>Signs of propofol-induced rhabdomyolysis may be different from those of malignant hyperthermia. Even a regular induction dose of propofol for adults could possibly trigger rhabdomyolysis similar to what is observed in children diagnosed with propofol infusion syndrome. Though rare, care should still be taken when administering propofol.</AbstractText> |
10,404 | The time dependent association of adrenaline administration and survival from out-of-hospital cardiac arrest. | Recommended for decades, the therapeutic value of adrenaline (epinephrine) in the resuscitation of patients with out-of-hospital cardiac arrest (OHCA) is controversial.</AbstractText>To investigate the possible time-dependent outcomes associated with adrenaline administration by Emergency Medical Services personnel (EMS).</AbstractText>A retrospective analysis of prospectively collected data from a near statewide cardiac resuscitation database between 1 January 2005 and 30 November 2013. Multivariable logistic regression was used to analyze the effect of the time interval between EMS dispatch and the initial dose of adrenaline on survival. The primary endpoints were survival to hospital discharge and favourable neurologic outcome.</AbstractText>Data from 3469 patients with witnessed OHCA were analyzed. Their mean age was 66.3 years and 69% were male. An initially shockable rhythm was present in 41.8% of patients. Based on a multivariable logistic regression model with initial adrenaline administration time interval (AATI) from EMS dispatch as the covariate, survival was greatest when adrenaline was administered very early but decreased rapidly with increasing (AATI); odds ratio 0.94 (95% Confidence Interval (CI) 0.92-0.97). The AATI had no significant effect on good neurological outcome (OR=0.96, 95% CI=0.90-1.02).</AbstractText>In patients with OHCA, survival to hospital discharge was greater in those treated early with adrenaline by EMS especially in the subset of patients with a shockable rhythm. However survival rapidly decreased with increasing adrenaline administration time intervals (AATI).</AbstractText>Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.</CopyrightInformation> |
10,405 | Acute Heart Failure and Atrial Fibrillation: Insights From the Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure (ASCEND-HF) Trial. | Patients with acute heart failure (AHF) frequently have atrial fibrillation (AF), but how this affects patient-reported outcomes has not been well characterized.</AbstractText>We examined dyspnea improvement and clinical outcomes in 7007 patients in the Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure (ASCEND-HF) trial. At baseline, 2677 (38.2%) patients had current or a history of AF and 4330 (61.8%) did not. Patients with a history of AF were older than those without (72 vs. 63 years) and had more comorbidities and a higher median left ventricular ejection fraction (31% vs. 27%, P<0.001). Compared to those without AF, patients with AF had a similar mean ventricular rate on admission (81 vs. 83 beats per minute [bpm]; P=0.138) but a lower rate at discharge (75 vs. 78 bpm; P<0.001). There was no difference in dyspnea improvement between patients with and without AF at 6 hours (P=0.087), but patients with AF had less dyspnea improvement at 24 hours (P<0.001). Compared to patients without AF, patients with AF had a higher 30-day all-cause mortality rate (4.7% vs. 3.3%; P=0.005), a higher 30-day HF rehospitalisation rate (7.2% vs. 5.3%; P=0.001), and a higher coprimary composite outcome of 30-day death or readmission (11.6% vs. 8.6%; P<0.001). This difference persisted after adjustment for prognostic variables (adjusted odds ratio=1.19; (95% confidence interval, 1.02 to 1.38; P=0.029).</AbstractText>Among patients admitted to the hospital with AHF, current or a history of AF is associated with less dyspnea improvement and higher morbidity and mortality at 30-days, compared to those not in AF.</AbstractText>URL: http://www.clinicaltrials.gov. Unique identifier: NCT00475852.</AbstractText>© 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.</CopyrightInformation> |
10,406 | Importance of non-pulmonary vein triggers ablation to achieve long-term freedom from paroxysmal atrial fibrillation in patients with low ejection fraction. | Whether ablation of non-pulmonary vein (PV) triggers after pulmonary vein antrum isolation (PVAI) improves the long-term procedure outcome in patients with paroxysmal atrial fibrillation (PAF) and left ventricular systolic dysfunction is unknown.</AbstractText>We sought to evaluate whether a more extensive ablation procedure improves outcomes at follow-up.</AbstractText>Consecutive patients with PAF refractory to antiarrhythmic drugs presenting for PVAI were prospectively studied. Patients were categorized into 2 groups: patients with left ventricular ejection fraction (LVEF) ≤35% (group I; n = 175) and patients with LVEF ≥50% (group II; n = 545). Patients in group I were further divided according to whether additional ablation of non-PV triggers was performed (group IA; n = 88) or not (group IB; n = 87). Long-term ablation success off antiarrhythmic drugs after a single procedure was analyzed.</AbstractText>Patients in group I had more non-PV triggers than did patients in group II (69.1% vs 26.6%; P < .001). During a follow-up of 15.8 ± 4.7 months, fewer patients in group I remained free from recurrences than those in group II (53.7% vs 81.7%; P < .001). Long-term ablation success was higher in group IA than in group IB (75.0% vs 32.2%; P < .001) and similar to that in group II (75.0% vs 81.7%; P = .44). In multivariate analysis, LVEF ≤35% (hazard ratio 1.68; P = .003) and non-PV triggers (hazard ratio 3.12; P < .001) were independent predictors of recurrences.</AbstractText>In patients with PAF and left ventricular systolic dysfunction, ablation of non-PV triggers in addition to PVAI significantly improves their long-term procedure outcome.</AbstractText>Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,407 | Influence of Baseline Characteristics, Operative Conduct, and Postoperative Course on 30-Day Outcomes of Coronary Artery Bypass Grafting Among Patients With Left Ventricular Dysfunction: Results From the Surgical Treatment for Ischemic Heart Failure (STICH) Trial. | Patients with severe left ventricular dysfunction, ischemic heart failure, and coronary artery disease suitable for coronary artery bypass grafting (CABG) are at higher risk for surgical morbidity and mortality. Paradoxically, those patients with the most severe coronary artery disease and ventricular dysfunction who derive the greatest clinical benefit from CABG are also at the greatest operative risk, which makes decision making regarding whether to proceed to surgery difficult in such patients. To better inform such decision making, we analyzed the Surgical Treatment for Ischemic Heart Failure (STICH) CABG population for detailed information on perioperative risk and outcomes.</AbstractText>In both STICH trials (hypotheses), 2136 patients with a left ventricular ejection fraction of ≤35% and coronary artery disease were allocated to medical therapy, CABG plus medical therapy, or CABG with surgical ventricular reconstruction. Relationships of baseline characteristics and operative conduct with morbidity and mortality at 30 days were evaluated. There were a total of 1460 patients randomized to and receiving surgery, and 346 (≈25%) of these high-risk patients developed a severe complication within 30 days. Worsening renal insufficiency, cardiac arrest with cardiopulmonary resuscitation, and ventricular arrhythmias were the most frequent complications and those most commonly associated with death. Mortality at 30 days was 5.1% and was generally preceded by a serious complication (65 of 74 deaths). Left ventricular size, renal dysfunction, advanced age, and atrial fibrillation/flutter were significant preoperative predictors of mortality within 30 days. Cardiopulmonary bypass time was the only independent surgical variable predictive of 30-day mortality.</AbstractText>CABG can be performed with relatively low 30-day mortality in patients with left ventricular dysfunction. Serious postoperative complications occurred in nearly 1 in 4 patients and were associated with mortality.</AbstractText>URL: http://www.clinicaltrials.gov. Unique identifier: NCT00023595.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,408 | Novel Clinical Manifestation of the Known SCN5A D1790G Mutation. | The D1790G mutation was found in all 24 patients of an extended long QT family but not in 200 chromosomes carried by healthy individuals. We describe a 37-year-old man presenting with a typical spontaneous type 1 Brugada pattern who in electrophysiological testing had easily inducible ventricular fibrillation. At the age of 47 years he had an atrial ventricular type 2 block documented by an exercise test and a Holter monitor. Genetic analysis revealed a known D1790G mutation in the gene encoding of the sodium channel (SCN5A) that until now has been associated only with the long QT phenotype. Although this mutation has not been associated with a reduction of sodium channel expression, we hypothesize that sodium currents are further diminished due to the 20-mV shift of the steady-state inactivation curve, and this could contribute to the Brugada phenotype. This case is important as it allows a better understanding of the underlying molecular mechanisms of Brugada syndrome. Moreover, this observation raises concern about the safety of class IC drug therapy in long QT type 3 patients and quinidine therapy in Brugada patients, and emphasizes the importance of a thorough clinical and genetic evaluation. |
10,409 | The role of defibrillation testing. | The induction and termination of ventricular fibrillation at the time of defibrillator insertion (defibrillation testing [DT]) has traditionally been an integral component of implantable cardioverter-defibrillator (ICD) implantation. However, over the last 10 years, published series suggested a high rate of first-shock efficacy for clinical ventricular arrhythmias, even if no DT was done. Over the same time, several published reports and series have shown uncommon but serious complications related to DT. Throughout the world, there has been a steady decline in the proportion of patients receiving an ICD who undergo DT, which, in many regions, is less than 50%. |
10,410 | Management of pace-terminated ventricular arrhythmias. | An implantable-cardioverter defibrillator (ICD) can terminate ventricular arrhythmias by delivering a shock or by antitachycardia pacing (ATP). The ATP works by capturing the excitable gap and disrupting re-entrant ventricular arrhythmias. Multiple studies have demonstrated that ATP is successful at terminating ventricular tachycardia (VT). Shocks from the ICD are associated with higher mortality. The data are conflicting about whether appropriate ATP is associated with higher mortality. In a patient with VT that is treated by ATP, the patient's guideline-based heart failure medications should be maximized. The use of VT ablation after appropriate and successful ATP requires additional studies. |
10,411 | Left atrial appendage closure is preferred to chronic warfarin therapy: the pro perspective. | Atrial fibrillation (AF) is associated with increased rates of death, stroke, heart failure, hospitalization, degraded quality of life, reduced exercise capacity, and left ventricular dysfunction. An oral anticoagulant reduces the risk of stroke; however, it places the patient at risk for bleeding complications. Weighing the stroke and bleeding risks remains the key for optimal treatment. Cardiac interventions that can obviate long-term oral anticoagulation hold great promise for the future care of patients with AF and high stroke risk. The percutaneously deployable Watchman device is a paradigm shift in how clinicians can abate the need for continued oral anticoagulation. |
10,412 | Electrophysiology testing and catheter ablation are helpful when evaluating asymptomatic patients with Wolff-Parkinson-White pattern: the pro perspective. | Important advances in the natural history and diagnosis of, and therapy for, asymptomatic Wolff-Parkinson-White (WPW) syndrome have been made in the last decade by our group. These data have necessitated revisiting current practice guidelines to decide on the optimal management of the asymptomatic WPW population. There has also been an emphasis on identifying initially asymptomatic individuals who are at risk by nationwide screening programs using the electrocardiogram for prophylactic catheter ablation to prevent the lifetime risk of sudden cardiac death, particularly in young asymptomatic people, because only a subgroup of them is at high risk, requiring early catheter ablation. |
10,413 | Novel Uses of Targeted Temperature Management. | Targeted temperature management has an established role in treating the post-cardiac arrest syndrome after out-of-hospital cardiac arrest with an initial rhythm of ventricular tachycardia/ventricular fibrillation. There is less certain benefit if the initial rhythm is pulseless electrical activity/asystole or for in-hospital cardiac arrest. Targeted temperature management may have a role as salvage modality for conditions causing intracranial hypertension, such as traumatic brain injury, hepatic encephalopathy, intracerebral hemorrhage, and acute stroke. There is variable evidence for its use early in these disorders to minimize secondary neurologic injury. |
10,414 | Investigation of the antifibrillatory drug interactions between Amiodarone and Ibutilide in isolated, perfused Rabbit hearts. | In view of the reliability of the serial-shock method of measuring ventricular fibrillation threshold (VFT) in quantitatively assessing the antifibrillatory potency of many anti-arrhythmic drugs and the alarming reports of the proarrhythmic effects of several anti-arrhythmic agents, it was decided to use the above technique to study the possible interactions that may occur when anti-arrhythmic drugs from different classes are combined. Hearts isolated from New Zealand white rabbits of either sex weighing 1.5-2 kg were perfused by the Langendorff method with McEwen's solution. In six hearts, measurement of VFT was made in the absence of any drug throughout the experiments. Perfusion with either amiodarone or ibutilide produced significant, dose-dependent increase in VFT. In addition, there was no significant difference in the increase in VFT produced by the combined infusion of 1 μmol of amiodarone and 0.01 μmol of ibutilide and the summation of the increases produced by the separate infusion of these two concentrations. This is in contrast to a significant synergistic antifibrillatory effect of the combined use of lidocaine and propranolol that was reported previously. The lack of antifibrillatory interactions between amiodarone and Ibutilide may suggest the safety of combining the two drugs in the treatment of cardiac arrhythmias. However, further studies are required to establish this in the clinical setup. |
10,415 | Ventricular repolarization markers for predicting malignant arrhythmias in clinical practice. | Malignant cardiac arrhythmias which result in sudden cardiac death may be present in individuals apparently healthy or be associated with other medical conditions. The way to predict their appearance represents a challenge for the medical community due to the tragic outcomes in most cases. In the last two decades some ventricular repolarization (VR) markers have been found to be useful to predict malignant cardiac arrhythmias in several clinical conditions. The corrected QT, QT dispersion, Tpeak-Tend, Tpeak-Tend dispersion and Tp-e/QT have been studied and implemented in clinical practice for this purpose. These markers are obtained from 12 lead surface electrocardiogram. In this review we discuss how these markers have demonstrated to be effective to predict malignant arrhythmias in medical conditions such as long and short QT syndromes, Brugada syndrome, early repolarization syndrome, acute myocardial ischemia, heart failure, hypertension, diabetes mellitus, obesity and highly trained athletes. Also the main pathophysiological mechanisms that explain the arrhythmogenic predisposition in these diseases and the basis for the VR markers are discussed. However, the same results have not been found in all conditions. Further studies are needed to reach a global consensus in order to incorporate these VR parameters in risk stratification of these patients. |
10,416 | Worsening heart failure during hospitalization for acute heart failure: Insights from the Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure (ASCEND-HF). | Despite initial in-hospital treatment of acute heart failure (HF), some patients experience worsening HF (WHF). There are limited data about the outcomes and characteristics of patients who experience in-hospital WHF.</AbstractText>We assessed the characteristics and outcomes of patients with and without WHF in the ASCEND-HF trial. Worsening HF was defined as at least 1 symptom or sign of new, persistent, or WHF requiring additional intravenous inotropic/vasodilator or mechanical therapy during index hospitalization. We assessed the relationship between WHF and 30-day mortality, 30-day mortality or HF hospitalization, and 180-day mortality. We also assessed whether there was a differential association between early (days 1-3) vs late (day ≥4) WHF and outcomes. Of 7,141 patients with acute HF, 354 (5%) experienced WHF. Patients with WHF were more often male and had a history of atrial fibrillation or diabetes, lower blood pressure, and higher creatinine. After risk adjustment, WHF was associated with increased 30-day mortality (odds ratio 13.37, 95% CI 9.85-18.14), 30-day mortality or HF rehospitalization (odds ratio 6.78, 95% CI 5.25-8.76), and 180-day mortality (hazard ratio 3.90, 95% CI 3.14-4.86) (all P values < .0001). There was no evidence of a difference in outcomes between early and late WHF (all P values for comparison ≥ .2).</AbstractText>Worsening HF during index hospitalization was associated with worse 30- and 180-day outcomes. Worsening HF may represent an important patient-centered outcome in acute HF and a focus of future treatments.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,417 | Cardiac resynchronization therapy update: evolving indications, expanding benefit? | Cardiac resynchronisation therapy (CRT) is an effective intervention for appropriately selected patients with heart failure, but exactly how it works is uncertain. Recent data suggest that much, or perhaps most, of the benefits of CRT are not delivered by re-coordinating left ventricular dyssynchrony. Atrio-ventricular resynchronization, reduction in mitral regurgitation and prevention of bradycardia are other potential mechanisms of benefit that will vary from one patient to the next and over time. Because there is no single therapeutic target, it is unlikely that any single measure will accurately predict benefit. The only clinical characteristic that appears to be a useful predictor of the benefits of CRT is a QRS duration of >140 ms. Many new approaches are being developed to try to improve the effectiveness of and extend the indications for CRT. These include smart pacing algorithms, better pacing-site targeting, new sensors, multipoint pacing, remote device monitoring and leadless endocardial pacing. Whether CRT is effective in patients with atrial fibrillation or whether adding a defibrillator function to CRT improves prognosis awaits further evidence. |
10,418 | Reduced Irregularity of Ventricular Response During Atrial Fibrillation and Long-term Outcome in Patients With Heart Failure. | Reduced heart rate variability (HRV) is associated with poor outcome in patients with heart failure (HF). However, the data on predictive value of RR variability during atrial fibrillation (AF) are limited. Therefore, the aim of this study was to evaluate the association between ventricular response characteristics and long-term clinical outcome in the population of ambulatory patients with mild-to-moderate HF and AF at baseline. The study included 155 patients (mean age 69 ± 10 years) with AF at 20-minute Holter electrocardiographic (ECG) recordings at enrollment. HRV analysis included SDNN, rMSSD, and pNN50, whereas irregularity indexes included 2 nonlinear parameters: approximate entropy (ApEn) and Shannon entropy. After median 41 months of follow-up, 54 patients died, including 21 HF related and 16 sudden deaths. Patients with ApEn ≤1.68 (lower tertile) had 40% mortality versus 12% in others (p <0.001) at 2 years of follow-up. Only nonlinear HRV parameters (irregularity but not variability indexes) identified patients at higher risk during follow-up. Decreased ApEn ≤1.68 was an independent predictor of total mortality (hazard ratio [HR] 2.81, 95% confidence interval [CI] 1.61 to 4.89, p <0.001), sudden cardiac death (HR 3.83, 95% CI 1.31 to 11.25, p = 0.014), and HF death (HR 3.45, 95% CI 1.42 to 8.38, p = 0.006) in a multivariate Cox analysis. In conclusion, in a post hoc analysis of Muerte Subita en Insufficiencia Cardiaca study AF cohort, reduced irregularity of RR intervals during AF, likely caused by autonomic dysfunction, was an independent predictor of all-cause mortality and sudden death and HF progression in patients with mild-to-moderate HF, whereas traditional HRV indexes did not predict outcome. |
10,419 | Prearrest hypothermia improved defibrillation and cardiac function in a rabbit ventricular fibrillation model. | Hypothermia when cardiopulmonary resuscitation begins may help achieve defibrillation and return of spontaneous circulation (ROSC), but few data are available.</AbstractText>The objective of this study was to determine whether prearrest hypothermia improved defibrillation and cardiac function in a rabbit ventricular fibrillation (VF) model.</AbstractText>Thirty-six New Zealand rabbits were randomized equally to receive normothermia (Norm) (~39°C), post-ROSC hypothermia (~33°C), or prearrest hypothermia (~33°C). Ventricular fibrillation was induced by alternating current. After 4 minutes of VF, rabbits were defibrillated and given cardiopulmonary resuscitation until ROSC or no response (≥30 minutes). Hemodynamics and electrocardiogram were monitored; N-terminal pro-brain natriuretic peptideand troponin I were determined by enzyme-linked immunosorbent assay. Myocardial histology and echocardiographic data were evaluated. First-shock achievement of perfusion rhythm was more frequent in prearrest than normothermic animals (7/12 vs 1/12; P=.027). After ROSC, dp/dtmax was higher in prearrest than normothermic animals (P<.001). Left ventricular end-systolic pressure was higher in prearrest than normothermic animals (P=.001). At 240 minutes after ROSC, troponin I and N-terminal pro-brain natriuretic peptide were lower in prearrest than normothermic animals (15.74±2.26 vs 25.09±1.85 ng/mL and 426±23 vs 284±45 pg/mL, respectively), the left ventricular ejection fraction and cardiac output were lower in the Norm group than other 2 groups (P<.01). Myocardial histology was more disturbed in normothermic than post-ROSC and prearrest animals, but was not different in the latter 2 groups.</AbstractText>Induction of hypothermia before VF led to improved cardiac function in a rabbit VF model through improving achievement of perfusing rhythm by first-shock defibrillation and facilitating resuscitation.</AbstractText>Copyright © 2015. Published by Elsevier Inc.</CopyrightInformation> |
10,420 | Prolonged cooling duration mitigates myocardial and cerebral damage in cardiac arrest. | The purpose of this study was to investigate the effect of prolonged cooling on cardiac and cerebral injury in animals under cardiac arrest.</AbstractText>Adult male Wistar rats were equally randomized to normothermia, 5H1, 5H2, 7H1, 7H2, and 7H4 groups. The first number in the group name indicated ventricular fibrillation duration (minutes), the middle H indicated hypothermia, and the last number signified hypothermia duration (hours). Ventricular fibrillation was induced and untreated for 5 minutes (normothermia, 5H1, and 5H2) or 7 minutes (7H1, 7H2, and 7H4) followed by 1 minute of cardiopulmonary resuscitation followed by electric shocks. Hypothermia was initiated simultaneously with cardiopulmonary resuscitation initiation and maintained for 1 hour (5H1 and 7H1), 2 hours (5H2 and 7H2) or 4 hours (7H4).</AbstractText>There were 12 rats in each group. Compared with the 7H1 group, the 7H4 group had significantly better systolic function (dp/dt40) and cardiac output within the early postcardiac arrest period. Histologic examination disclosed less myocardial and hippocampal damage in the 7H4 group than the 7H1 group and in the 5H2 group than the 5H1 group. Plasma troponin I, fatty acid-binding protein, and S-100β concentrations were significantly lower in the 7H4 and 5H2 groups. The 7H4 and 5H2 groups survived statistically longer than the groups with shorter cooling duration.</AbstractText>Slightly prolonging hypothermia may mitigate myocardial and cerebral damage and improve survival and neurologic outcomes in a rat model of ventricular fibrillation cardiac arrest.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,421 | SPEAR Trial: Smartphone Pediatric ElectrocARdiogram Trial. | Smartphone-enabled ECG devices have the potential to improve patient care by enabling remote ECG assessment of patients with potential and diagnosed arrhythmias. This prospective study aimed to assess the usefulness of pediatric ECG tracings generated by the AliveCor device (Oklahoma City, OK) and to assess user satisfaction.</AbstractText>Enrolled pediatric patients with documented paroxysmal arrhythmia used the AliveCor device over a yearlong study period. Pediatric electrophysiologists reviewed all transmitted ECG tracings. Patient completed surveys were analyzed to assess user satisfaction.</AbstractText>35 patients were enrolled with the following diagnoses: supraventricular tachycardia (SVT, 57%), atrial fibrillation (AF, 11%), ectopic atrial tachycardia (EAT, 6%), atrial tachycardia (AT, 3%), and ventricular tachycardia (VT, 23%). A total of 238 tracings were received from 20 patients, 96% of which were of diagnostic quality for sinus rhythm, sinus tachycardia, SVT, and AF. 126 patient satisfaction surveys (64% from parents) were completed. 98% of the survey responses indicated that it was easy to obtain tracings, 93% found it easy to transmit the tracings, 98% showed added comfort in managing arrhythmia by having the device, and 93% showed interest in continued use of the device after the study period ended.</AbstractText>Smartphone-enabled ECG devices can generate tracings of diagnostic quality in children. User satisfaction was extremely positive. Use of the device to manage certain patients with AF and SVT showcases the future role of remote ECGs in the successful outpatient management of arrhythmias in children by potentially reducing Emergency Department visits and healthcare costs.</AbstractText> |
10,422 | Prophylactic lidocaine for myocardial infarction. | Coronary artery disease is a major public health problem affecting both developed and developing countries. Acute coronary syndromes include unstable angina and myocardial infarction with or without ST-segment elevation (electrocardiogram sector is higher than baseline). Ventricular arrhythmia after myocardial infarction is associated with high risk of mortality. The evidence is out of date, and considerable uncertainty remains about the effects of prophylactic use of lidocaine on all-cause mortality, in particular, in patients with suspected myocardial infarction.</AbstractText>To determine the clinical effectiveness and safety of prophylactic lidocaine in preventing death among people with myocardial infarction.</AbstractText>We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 3), MEDLINE Ovid (1946 to 13 April 2015), EMBASE (1947 to 13 April 2015) and Latin American Caribbean Health Sciences Literature (LILACS) (1986 to 13 April 2015). We also searched Web of Science (1970 to 13 April 2013) and handsearched the reference lists of included papers. We applied no language restriction in the search.</AbstractText>We included randomised controlled trials assessing the effects of prophylactic lidocaine for myocardial infarction. We considered all-cause mortality, cardiac mortality and overall survival at 30 days after myocardial infarction as primary outcomes.</AbstractText>We performed study selection, risk of bias assessment and data extraction in duplicate. We estimated risk ratios (RRs) for dichotomous outcomes and measured statistical heterogeneity using I(2). We used a random-effects model and conducted trial sequential analysis.</AbstractText>We identified 37 randomised controlled trials involving 11,948 participants. These trials compared lidocaine versus placebo or no intervention, disopyramide, mexiletine, tocainide, propafenone, amiodarone, dimethylammonium chloride, aprindine and pirmenol. Overall, trials were underpowered and had high risk of bias. Ninety-seven per cent of trials (36/37) were conducted without an a priori sample size estimation. Ten trials were sponsored by the pharmaceutical industry. Trials were conducted in 17 countries, and intravenous intervention was the most frequent route of administration.In trials involving participants with proven or non-proven acute myocardial infarction, lidocaine versus placebo or no intervention showed no significant differences regarding all-cause mortality (213/5879 (3.62%) vs 199/5848 (3.40%); RR 1.02, 95% CI 0.82 to 1.27; participants = 11727; studies = 18; I(2) = 15%); low-quality evidence), cardiac mortality (69/4184 (1.65%) vs 62/4093 (1.51%); RR 1.03, 95% CI 0.70 to 1.50; participants = 8277; studies = 12; I(2) = 12%; low-quality evidence) and prophylaxis of ventricular fibrillation (76/5128 (1.48%) vs 103/4987 (2.01%); RR 0.78, 95% CI 0.55 to 1.12; participants = 10115; studies = 16; I(2) = 18%; low-quality evidence). In terms of sinus bradycardia, lidocaine effect is imprecise compared with effects of placebo or no intervention (55/1346 (4.08%) vs 49/1203 (4.07%); RR 1.09, 95% CI 0.66 to 1.80; participants = 2549; studies = 8; I(2) = 21%; very low-quality evidence). In trials involving only participants with proven acute myocardial infarction, lidocaine versus placebo or no intervention showed no significant differences in all-cause mortality (148/2747 (5.39%) vs 135/2506 (5.39%); RR 1.01, 95% CI 0.79 to 1.30; participants = 5253; studies = 16; I(2) = 9%; low-quality evidence). No significant differences were noted between lidocaine and any other antiarrhythmic drug in terms of all-cause mortality and ventricular fibrillation. Data on overall survival 30 days after myocardial infarction were not reported. Lidocaine compared with placebo or no intervention increased risk of asystole (35/3393 (1.03%) vs 14/3443 (0.41%); RR 2.32, 95% CI 1.26 to 4.26; participants = 6826; studies = 4; I(2) = 0%; very low-quality evidence) and dizziness/drowsiness (74/1259 (5.88%) vs 16/1274 (1.26%); RR 3.85, 95% CI 2.29 to 6.47; participants = 2533; studies = 6; I(2) = 0%; low-quality evidence). Overall, safety data were poorly reported and adverse events may have been underestimated. Trial sequential analyses suggest that additional trials may not be needed for reliable conclusions to be drawn regarding these outcomes.</AbstractText><AbstractText Label="AUTHORS' CONCLUSIONS" NlmCategory="CONCLUSIONS">This Cochrane review found evidence of low quality to suggest that prophylactic lidocaine has very little or no effect on mortality or ventricular fibrillation in people with acute myocardial infarction. The safety profile is unclear. This conclusion is based on randomised controlled trials with high risk of bias. However (disregarding the risk of bias), trial sequential analysis suggests that additional trials may not be needed to disprove an intervention effect of 20% relative risk reduction. Smaller risk reductions might require additional higher trials.</AbstractText> |
10,423 | Cardiac Fibrosis in Patients With Atrial Fibrillation: Mechanisms and Clinical Implications. | Atrial fibrillation (AF) is associated with structural, electrical, and contractile remodeling of the atria. Development and progression of atrial fibrosis is the hallmark of structural remodeling in AF and is considered the substrate for AF perpetuation. In contrast, experimental and clinical data on the effect of ventricular fibrotic processes in the pathogenesis of AF and its complications are controversial. Ventricular fibrosis seems to contribute to abnormalities in cardiac relaxation and contractility and to the development of heart failure, a common finding in AF. Given that AF and heart failure frequently coexist and that both conditions affect patient prognosis, a better understanding of the mutual effect of fibrosis in AF and heart failure is of particular interest. In this review paper, we provide an overview of the general mechanisms of cardiac fibrosis in AF, differences between fibrotic processes in atria and ventricles, and the clinical and prognostic significance of cardiac fibrosis in AF. |
10,424 | Dual-chamber pacemakers for treating symptomatic bradycardia due to sick sinus syndrome without atrioventricular block: a systematic review and economic evaluation. | Bradycardia [resting heart rate below 60 beats per minute (b.p.m.)] can be caused by conditions affecting the natural pacemakers of the heart, such as sick sinus syndrome (SSS) and atrioventricular (AV) blocks. People suffering from bradycardia may present with palpitations, exercise intolerance and fainting. The only effective treatment for patients suffering from symptomatic bradycardia is implantation of a permanent pacemaker.</AbstractText>To appraise the clinical effectiveness and cost-effectiveness of dual-chamber pacemakers compared with single-chamber atrial pacemakers for treating symptomatic bradycardia in people with SSS and no evidence of AV block.</AbstractText>All databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Health Technology Assessment database, NHS Economic Evaluations Database) were searched from inception to June 2014.</AbstractText>A systematic review of the clinical and economic literature was carried out in accordance with the general principles published by the Centre for Reviews and Dissemination. Randomised controlled trials (RCTs) evaluating dual-chamber and single-chamber atrial pacemakers and economic evaluations were included. Pairwise meta-analysis was carried out. A de novo economic model was developed.</AbstractText>Of 493 references, six RCTs were included in the review. The results were predominantly influenced by the largest trial DANPACE. Dual-chamber pacing was associated with a statistically significant reduction in reoperation [odds ratio (OR) 0.48, 95% confidence interval (CI) 0.36 to 0.63] compared with single-chamber atrial pacing. The difference is primarily because of the development of AV block requiring upgrade to a dual-chamber device. The risk of paroxysmal atrial fibrillation was also reduced with dual-chamber pacing compared with single-chamber atrial pacing (OR 0.75, 95% CI 0.59 to 0.96). No statistically significant difference was found between the pacing modes for mortality, heart failure, stroke, chronic atrial fibrillation or quality of life. However, the risk of developing heart failure may vary with age and device. The de novo economic model shows that dual-chamber pacemakers are more expensive and more effective than single-chamber atrial devices, resulting in a base-case incremental cost-effectiveness ratio (ICER) of £6506. The ICER remains below £20,000 in probabilistic sensitivity analysis, structural sensitivity analysis and most scenario analyses and one-way sensitivity analyses. The risk of heart failure may have an impact on the decision to use dual-chamber or single-chamber atrial pacemakers. Results from an analysis based on age (> 75 years or ≤ 75 years) and risk of heart failure indicate that dual-chamber pacemakers dominate single-chamber atrial pacemakers (i.e. are less expensive and more effective) in older patients, whereas dual-chamber pacemakers are dominated by (i.e. more expensive and less effective) single-chamber atrial pacemakers in younger patients. However, these results are based on a subgroup analysis and should be treated with caution.</AbstractText>In patients with SSS without evidence of impaired AV conduction, dual-chamber pacemakers appear to be cost-effective compared with single-chamber atrial pacemakers. The risk of developing a complete AV block and the lack of tools to identify patients at high risk of developing the condition argue for the implantation of a dual-chamber pacemaker programmed to minimise unnecessary ventricular pacing. However, considerations have to be made around the risk of developing heart failure, which may depend on age and device.</AbstractText>This study is registered as PROSPERO CRD42013006708.</AbstractText>The National Institute for Health Research Health Technology Assessment programme.</AbstractText> |
10,425 | Brugada Syndrome Phenotype Elimination by Epicardial Substrate Ablation. | Whether Brugada syndrome (BrS) depends on functional epicardial substrates, which may be definitively eliminated by radiofrequency ablation, remains unknown.</AbstractText>Patients with BrS underwent epicardial mapping to identify areas of abnormal electrograms as target for radiofrequency ablation. Substrate identification consisted in mapping right ventricle epicardial surface before and after flecainide (2 mg/kg per 10 minutes). After radiofrequency ablation, flecainide and remap confirmed elimination of abnormal substrate, BrS ECG pattern, and ventricular tachycardia/ventricular fibrillation inducibility. Flecainide testing was performed at each follow-up visits ≤6 months. Fourteen patients with BrS, median age 39 years (30.3-42.3) with implantable cardioverter-defibrillator were enrolled. Low-voltage areas (<1.5 mV) were commonly identified on the anterior right free wall and right ventricular outflow tract, which increased after flecainide from 17.6 cm(2) (12.1-24.2) to 28.5 cm(2) (21.6-30.2; P=0.001). Similarly, areas with abnormal electrograms increased after flecainide from 19.0 (17.5-23.6) to 27.3 cm(2) (24.0-31.2; P=0.001). After 23.8 minutes (18.1-28.5) of radiofrequency ablation, abnormal electrograms disappeared, whereas low-voltage areas were replaced by scar areas (<0.5 mV) of 25.9 cm(2) (19.6-31.0). Substrate elimination resulted in BrS ECG pattern disappearance and no ventricular tachycardia/ventricular fibrillation inducibility without complications. After a median follow-up of 5 months (3.8-5.3), ECG remained normal despite flecainide.</AbstractText>In patients with BrS, there is a relationship between abnormal ECG pattern, the extent of abnormal epicardial substrate, and ventricular tachycardia/ventricular fibrillation inducibility. Ablation of the substrate identified in the presence of flecainide can eliminate the BrS phenotype and warrants further study.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,426 | Coronary artery problems late after arterial switch operation for transposition of the great arteries. | The incidence of late coronary artery abnormalities after arterial switch operation (ASO) for d-loop transposition of the great arteries may be underestimated.</AbstractText><AbstractText Label="METHODS AND RESULTS" NlmCategory="RESULTS">We retrospectively reviewed coronary artery morphology in 40 of 97 patients who survived the first year after ASO. Seven asymptomatic patients developed significant late coronary artery abnormalities. One patient died suddenly at home with severe left coronary artery (LCA) ostial stenosis at age 3.8 years. The second patient collapsed during exercise at age 9.6 years due to ventricular fibrillation and severe LCA ostial stenosis despite prior negative exercise stress test (EST) and myocardial perfusion imaging (MPI). The third patient was found to have moderate ostial stenosis of the LCA with negative EST and MPI. The fourth patient with exercise-induced ST-T depression and myocardial perfusion defect was shown to have complete LCA occlusion with collateral vessel formation. Three other patients had complete proximal obliteration of either of the coronary arteries with collateral supply. An additional 4 asymptomatic patients had trivial-mild narrowing of the LCA on routine selective coronary angiogram.</AbstractText>Incidence of late coronary stenosis or occlusion was not infrequent after ASO (11.3%) and presented usually without preceding symptoms and often after negative non-invasive screening. We advocate routine coronary imaging in all patients after ASO before they participate in competitive sports.</AbstractText> |
10,427 | Association between left ventricular global longitudinal strain and natriuretic peptides in outpatients with chronic systolic heart failure. | Both impaired left ventricular (LV) global longitudinal strain (GLS) and increased plasma concentrations of natriuretic peptides(NP) are associated with a poor outcome in heart failure (HF). Increased levels of NP reflect increased wall stress of the LV. However, little is known about the relationship between LV GLS and NP. This aim of this study was to evaluate the relationship between the echocardiographic measure LV GLS and plasma levels of NP.</AbstractText>We prospectively included 149 patients with verified systolic HF at the baseline visit in an outpatient HF clinic. LV GLS was assessed by two dimension speckle tracking and plasma concentrations of N-terminal-pro-brain-natriuretic-peptide (NT-proBNP) and pro-atrial-natriuretic-peptide (proANP) were analysed.</AbstractText>The patients had a median age of 70 years, 28.2 % were females, 26.5 % were in functional class III-IV, median left ventricular ejection fraction (LVEF) was 33 % and median LV GLS was -11 %. LV GLS was associated with increased plasma concentrations of NT-proBNP and proANP in multivariate logistic regression (NT-proBNP: Odds RatioGLS: 7.25, 95 %-CI: 2.48-21.1, P < 0.001 and proANP: Odds RatioGLS: 3.26, 95-%-CI: 1.28-8.30, P = 0.013) and linear regression (NT-proBNP: βGLS: 1.19, 95 %-CI: 0.62-1.76, P < 0.001 and proANP: βGLS: 0.42, 95-%-CI: 0.11-0.72, P = 0.007) models after adjustment for traditional confounders (age, gender, body-mass-index, atrial fibrillation, renal function) and left atrial volume index.</AbstractText>Impaired LV GLS is associated with increased plasma concentrations of NP and our data suggest that left ventricular myocardial mechanics estimated by LV GLS reflects myocardial wall stress in chronic systolic HF.</AbstractText> |
10,428 | Cardiac devices with class 1C antiarrhythmics: a potentially toxic combination. | A patient taking regular flecainide for paroxysmal atrial fibrillation presented with broad complex tachycardia and circulatory compromise. With no history of pacemaker insertion and no pacing spikes visible on the ECG, this was presumed to be ventricular tachycardia and treated with electrical cardioversion, leading to p-wave asystole. An indwelling pacemaker was now recognised and ventricular capture was eventually attained by significantly increasing ventricular lead output. Invasive haemodynamic support was required due to new ventricular systolic dysfunction. Pacing thresholds and ventricular function normalised within 72 h consistent with flecainide toxicity; levels were shown to be toxic. Pacemaker interrogation revealed evidence of an undiagnosed atrial flutter, at presentation this was likely slowed by flecainide toxicity to a rate below the pacemaker mode switch, such that it was tracked in the ventricle at the upper tracking rate (120 bpm). Cardioversion terminated the arrhythmia but raised the capture threshold of the ventricle above the maximum lead output. |
10,429 | Sodium channel haploinsufficiency and structural change in ventricular arrhythmogenesis. | Normal cardiac excitation involves orderly conduction of electrical activation and recovery dependent upon surface membrane, voltage-gated, sodium (Na(+) ) channel α-subunits (Nav 1.5). We summarize experimental studies of physiological and clinical consequences of loss-of-function Na(+) channel mutations. Of these conditions, Brugada syndrome (BrS) and progressive cardiac conduction defect (PCCD) are associated with sudden, often fatal, ventricular tachycardia (VT) or fibrillation. Mouse Scn5a(+/-) hearts replicate important clinical phenotypes modelling these human conditions. The arrhythmic phenotype is associated not only with the primary biophysical change but also with additional, anatomical abnormalities, in turn dependent upon age and sex, each themselves exerting arrhythmic effects. Available evidence suggests a unified binary scheme for the development of arrhythmia in both BrS and PCCD. Previous biophysical studies suggested that Nav 1.5 deficiency produces a background electrophysiological defect compromising conduction, thereby producing an arrhythmic substrate unmasked by flecainide or ajmaline challenge. More recent reports further suggest a progressive decline in conduction velocity and increase in its dispersion particularly in ageing male Nav 1.5 haploinsufficient compared to WT hearts. This appears to involve a selective appearance of slow conduction at the expense of rapidly conducting pathways with changes in their frequency distributions. These changes were related to increased cardiac fibrosis. It is thus the combination of the structural and biophysical changes both accentuating arrhythmic substrate that may produce arrhythmic tendency. This binary scheme explains the combined requirement for separate, biophysical and structural changes, particularly occurring in ageing Nav 1.5 haploinsufficient males in producing clinical arrhythmia. |
10,430 | Anemia as an Independent Predictor of Adverse Cardiac Outcomes in Patients with Atrial Fibrillation. | Anemia and echocardiographic systolic and diastolic parameters are useful predictors of cardiovascular outcomes in patients with atrial fibrillation (AF). However, no studies have evaluated the use of anemia for predicting cardiovascular outcome in AF patients when the important echocardiographic parameters are known. Therefore, this study was designed to evaluate whether low hemoglobin is a useful parameter for predicting poor cardiac outcome after adjustment for important echocardiographic parameters in AF patients.</AbstractText>Index beat method was used to measure echocardiographic parameters in 166 patients with persistent AF. Cardiac events were defined as death and hospitalization for heart failure. The association of hemoglobin with adverse cardiac events was assessed by Cox proportional hazards model.</AbstractText>The 49 cardiac events identified in this population included 21 deaths and 28 hospitalizations for heart failure during an average follow-up of 20 months (25th-75th percentile: 14-32 months). Multivariable analysis showed that increased left ventricular mass index (LVMI) and decreased body mass index, estimated glomerular filtration rate, and hemoglobin (hazard ratio 0.827; P = 0.015) were independently associated with increased cardiac events. Additionally, tests of a Cox model that included important clinic variables, LVMI, left ventricular ejection fraction, and the ratio of transmitral E-wave velocity to early diastolic mitral annulus velocity showed that including hemoglobin significantly increased value in predicting adverse cardiac events (P = 0.010).</AbstractText>Hemoglobin is a useful parameter for predicting adverse cardiac events, and including hemoglobin may improve the prognostic prediction of conventional clinical and echocardiographic parameters in patients with AF.</AbstractText> |
10,431 | Mechanism, diagnosis, and treatment of outflow tract tachycardia. | Idiopathic ventricular arrhythmia is a generic term for a spectrum of arrhythmias that occur in the absence of structural heart disease or ion channelopathy. These arrhythmias include monomorphic premature ventricular contractions (PVCs), nonsustained monomorphic ventricular tachycardia (VT), and sustained VT. Most idiopathic ventricular arrhythmias originate from the right and left ventricular outflow tracts and include sites accessed from the aortic sinuses of Valsalva. Outflow tract arrhythmia is identified by an electrocardiographic pattern consistent with a left bundle branch block inferior axis morphology. Characteristically, outflow tract VT is caused by cAMP-mediated triggered activity, and is terminated by administration of adenosine. Outflow tract arrhythmias are focal and, therefore, are readily amenable to definitive treatment with catheter-based radiofrequency ablation. Although arrhythmia might be associated with reversible PVC-mediated cardiomyopathy, and infrequently with PVC-induced polymorphic VT or ventricular fibrillation, prognosis is generally favourable. |
10,432 | Start me up! Recurrent ventricular tachydysrhythmias following intentional concentrated caffeine ingestion. | Nearly pure caffeine is sold as a "dietary supplement," with instructions to ingest 1/64th to 1/16th of one teaspoon (50-200 mg). We report a patient with refractory cardiac dysrhythmias treated with defibrillation, beta-adrenergic blockade, and hemodialysis to highlight concentrated caffeine's dangers.</AbstractText>A 20-year-old woman presented with severe agitation, tremor, and vomiting approximately 1-2 h after suicidal ingestion of concentrated caffeine (powder and tablets). Within minutes, ventricular fibrillation commenced. Defibrillation, intubation, and amiodarone administration achieved return of spontaneous circulation (ROSC). Shortly thereafter, she developed pulseless ventricular tachycardia (VTach), with ROSC after defibrillation and lidocaine. She subsequently experienced 23 episodes of pulseless VTach, each responsive to defibrillation. Activated charcoal was administered via orogastric tube. An esmolol infusion was started. Hemodialysis was initiated once she was hemodynamically stable. She was extubated the following day, continued on oral metoprolol, and transferred to psychiatry on hospital day seven, achieving full neurological recovery. Serum caffeine concentrations performed approximately six and 18 h post-ingestion (pre/post-dialysis) were 240.8 mcg/mL and 150.7 mcg/mL.</AbstractText>Severe caffeine toxicity can produce difficult to treat, life-threatening dysrhythmias. Concentrated caffeine, marketed for dietary supplementation, presents a substantial public health risk that demands action to limit consumer availability.</AbstractText> |
10,433 | Role of adipose tissue in the pathogenesis of cardiac arrhythmias. | Epicardial adipose tissue is present in normal healthy individuals. It is a unique fat depot that, under physiologic conditions, plays a cardioprotective role. However, excess epicardial adipose tissue has been shown to be associated with prevalence and severity of atrial fibrillation. In arrhythmogenic right ventricular cardiomyopathy and myotonic dystrophy, fibrofatty infiltration of the myocardium is associated with ventricular arrhythmias. In the ovine model of ischemic cardiomyopathy, the presence of intramyocardial adipose or lipomatous metaplasia has been associated with increased propensity to ventricular tachycardia. These observations suggest a role of adipose tissue in the pathogenesis of cardiac arrhythmias. In this article, we review the role of cardiac adipose tissue in various cardiac arrhythmias and discuss the possible pathophysiologic mechanisms. |
10,434 | Non-invasive assessment of the effect of beta blockers and calcium channel blockers on the AV node during permanent atrial fibrillation. | We aimed at assessing changes in AV nodal properties during administration of the beta blockers metoprolol and carvedilol, and the calcium channel blockers diltiazem and verapamil from electrocardiographic data.</AbstractText>Parameters accounting for the functional refractory periods of the slow and fast pathways (aRPs and aRPf) were estimated using atrial fibrillatory rate (AFR) and ventricular response assessed from 15-min ECG segments recorded at baseline and on drug treatment from sixty patients with permanent AF.</AbstractText>The results showed that AFR and HR were significantly reduced for all drugs, and that aRPs and aRPf were significantly prolonged in both pathways. The prolongation in aRP was significantly larger for the calcium channel blockers than for the beta blockers.</AbstractText>The changes observed in the AV node parameters are in line with the results of previous electrophysiological studies performed in patients during sinus rhythm, therefore supporting the clinical value of the method.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,435 | Drug-associated arrhythmia in the military patient. | Members of the Armed Forces may be exposed to drugs, or combinations of drugs, with the potential to prolong the QRS or QT intervals. The effect of this is to increase the likelihood of developing dangerous ventricular tachyarrhythmias, including ventricular tachycardia, torsades de pointes or ventricular fibrillation. Common examples of the pharmacological agents associated include antibiotics, antiemetics and antimalarials. Genetic predisposition, electrolyte disturbance, anaesthesia and trauma may exacerbate the proarrhythmic effect of these medications. Screening of recruits does not detect all those with a genetic predisposition to drug-associated arrhythmias, so vigilance in preventing this iatrogenic disorder and recognising and appropriately managing it when present is important. This article explains the physiological basis of arrhythmogenesis, outlines the clinical features and provides guidance on investigation and management, with particular reference to military patients. |
10,436 | Sinus rhythm R-wave amplitude as a predictor of ventricular fibrillation undersensing in patients with implantable cardioverter-defibrillator. | Ventricular fibrillation (VF) is induced during implantable cardioverter-defibrillator (ICD) implantation to ensure that the ICD will sense, detect, and defibrillate VF. ICD implant guidelines state that the amplitude of the sinus rhythm R wave recorded from the ventricular electrogram should have amplitude ≥5 mV. No study has tested the relationship between sinus rhythm R-wave amplitude and VF sensing using modern, transvenous sensing electrodes.</AbstractText>The goal of this study was to determine whether there is a sinus rhythm R-wave amplitude cutoff that can be used to determine which patients are not at risk of VF undersensing.</AbstractText>A retrospective analysis of induced and spontaneous VF episodes from 2 clinical trials with 2022 patients was performed. Episodes with undersensing during the initial detection of VF were identified, and the distribution of sinus rhythm R-wave amplitudes for patients with and without VF undersensing was analyzed.</AbstractText>Only 3% of analyzed induced VF episodes were considered to have VF undersensing, and none had clinically significant detection delays. There was no correlation between device-measured, rectified sinus rhythm R-wave amplitude and VF undersensing at the time of implantation or during follow-up, although <4% of patients had sinus rhythm R-waves with amplitude <3 mV.</AbstractText>We analyzed true bipolar sensing of induced VF or spontaneous ventricular tachycardia/VF detected in the ICD VF zone. Sensing of VF was so reliable that clinically significant undersensing did not occur. Our findings do not support any recommended minimum sinus rhythm R wave to ensure reliable sensing of VF or the necessity of inducing VF to verify sensing for rectified sinus rhythm R-waves with amplitude ≥3 mV.</AbstractText>Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,437 | [Analysis of pacemaker ECGs]. | The key to a successful analysis of a pacemaker electrocardiogram (ECG) is the application of the systematic approach used for any other ECG without a pacemaker: analysis of (1) basic rhythm and rate, (2) QRS axis, (3) PQ, QRS and QT intervals, (4) morphology of P waves, QRS, ST segments and T(U) waves and (5) the presence of arrhythmias.</AbstractText>If only the most obvious abnormality of a pacemaker ECG is considered, wrong conclusions can easily be drawn. If a systematic approach is skipped it may be overlooked that e.g. atrial pacing is ineffective, the left ventricle is paced instead of the right ventricle, pacing competes with intrinsic conduction or that the atrioventricular (AV) conduction time is programmed too long. Apart from this analysis, a pacemaker ECG which is not clear should be checked for the presence of arrhythmias (e.g. atrial fibrillation, atrial flutter, junctional escape rhythm and endless loop tachycardia), pacemaker malfunction (e.g. atrial or ventricular undersensing or oversensing, atrial or ventricular loss of capture) and activity of specific pacing algorithms, such as automatic mode switching, rate adaptation, AV delay modifying algorithms, reaction to premature ventricular contractions (PVC), safety window pacing, hysteresis and noise mode.</AbstractText>A systematic analysis of the pacemaker ECG almost always allows a probable diagnosis of arrhythmias and malfunctions to be made, which can be confirmed by pacemaker control and can often be corrected at the touch of the right button to the patient's benefit.</AbstractText> |
10,438 | Molecular Basis of Hypokalemia-Induced Ventricular Fibrillation. | Hypokalemia is known to promote ventricular arrhythmias, especially in combination with class III antiarrhythmic drugs like dofetilide. Here, we evaluated the underlying molecular mechanisms.</AbstractText>Arrhythmias were recorded in isolated rabbit and rat hearts or patch-clamped ventricular myocytes exposed to hypokalemia (1.0-3.5 mmol/L) in the absence or presence of dofetilide (1 μmol/L). Spontaneous early afterdepolarizations (EADs) and ventricular tachycardia/fibrillation occurred in 50% of hearts at 2.7 mmol/L [K] in the absence of dofetilide and 3.3 mmol/L [K] in its presence. Pretreatment with the Ca-calmodulin kinase II (CaMKII) inhibitor KN-93, but not its inactive analogue KN-92, abolished EADs and hypokalemia-induced ventricular tachycardia/fibrillation, as did the selective late Na current (INa) blocker GS-967. In intact hearts, moderate hypokalemia (2.7 mmol/L) significantly increased tissue CaMKII activity. Computer modeling revealed that EAD generation by hypokalemia (with or without dofetilide) required Na-K pump inhibition to induce intracellular Na and Ca overload with consequent CaMKII activation enhancing late INa and the L-type Ca current. K current suppression by hypokalemia and dofetilide alone in the absence of CaMKII activation were ineffective at causing EADs.</AbstractText>We conclude that Na-K pump inhibition by even moderate hypokalemia plays a critical role in promoting EAD-mediated arrhythmias by inducing a positive feedback cycle activating CaMKII and enhancing late INa. Class III antiarrhythmic drugs like dofetilide sensitize the heart to this positive feedback loop.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,439 | A rabbit model of antegrade selective cerebral perfusion with cardioplegic arrest. | Due to the weak ascending aorta, it is extremely challenging to establish an anterograde selective cerebral perfusion (ASCP) model in rabbits, especially when cardioplegic arrest is required. Herein, the aim of this study was to establish a rabbit ASCP model with cardiac arrest being easily performed and being similar to the clinical scenario.</AbstractText>Twenty-two adult New Zealand white rabbits were selected for ASCP model establishment and another 22 rabbits were utilized for blood donation. The cardiopulmonary bypass (CPB) circuit consisted of a roller pump, a membrane oxygenator, a heat-cooler system and a blood reservoir, which were connected by silicone tubing. The total priming volume of the circuit was 70 ml. Cannulations on the right and left subclavian arteries were used for arterial inflow and cardioplegia perfusion, respectively. Venous drainage was conducted through the right atrial appendage. ASCP was initiated by clamping the innominate artery; the flow rate was maintained 10 ml/kg/minute and sustained for 60 minutes. After 120 minutes of reperfusion, the rabbits were sacrificed. The mean arterial pressure, heart rate, electrocardiogram and urine output were monitored. Arterial blood samples were analyzed at the following time points: after anesthesia, immediately after CPB, after aorta cross-clamping and cardioplegia perfusion, 5 min after the re-opening of the aorta and at CPB termination.</AbstractText>ASCP modeling was performed successfully on 18 rabbits and 4 rabbits unsuccessfully. Vital signs and blood gas indictors changed in an acceptable range throughout the experiments. One rabbit had ventricular fibrillation after re-opening of the ascending aorta. Obvious hemodilution occurred after the perfusion of cardioplegia, but the hematocrit improved after CPB termination.</AbstractText>By using cannulation of the subclavian artery rather than the aorta and with a low priming volume, we established a modified rabbit model of ASCP with cardioplegic arrest. The model has excellent repeatability and operability, which is similar to the clinic process and is suitable for the study of cerebral, cardiac and renal protection.</AbstractText>© The Author(s) 2015.</CopyrightInformation> |
10,440 | Safety and efficacy of glucose-insulin-potassium treatment in coronary artery bypass graft surgery and percutaneous coronary intervention. | The purpose of this meta-analysis was to evaluate protective effects of glucose-insulin-potassium (GIK) on outcomes after coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). We systematically searched Medline/Pubmed, Elsevier, Embase, Web of Knowledge and Google Scholar. A total of 1206 studies were retrieved during the extensive literature search of all major databases; however, 38 trials reporting the end-point of interest were selected. We performed a pooled analysis of outcomes following PCI: incidence of cardiac arrest [odds ratio (OR) of 0.91; 95% confidence interval (CI): 0.76-1.09; P = 0.3], stroke (OR of 1.71; 95% CI: 0.37-1.37; P = 0.3), cardiogenic shock (OR of 1.02; 95% CI: 0.92-1.14; P = 0.6), reinfarction (OR of 0.95; 95% CI: 0.81-1.14; P = 0.5) and mortality (OR of 1.04; 95% CI: 0.96-1.13; P = 0.3); and following CABG: incidence of atrial fibrillation (OR of 0.86; 95% CI: 0.70-1.05; P = 0.1), incidence of ventricular fibrillation (OR of 0.83; 95% CI: 0.62-1.13; P = 0.2), reinfarction (OR of 0.97; 95% CI: 0.74-1.27; P = 0.8), infection (OR of 1.04; 95% CI: 0.67-1.62; P = 0.8), length of intensive care unit stay (LIS) [standard mean differences (SMD) of -0.27; 95% CI: -0.40 to -0.14; P = 0.000], length of hospital stay (LHS) (SMD of -0.035; 95% CI: -0.12 to -0.05; P = 0.4) and mortality (OR of 0.72; 95% CI: 0.41-1.26; P = 0.2). Our results showed that GIK did not have considerable cardioprotective effects. However, patients undergoing CABG seem to be better responders to GIK therapy compared with patients undergoing PCI. Furthermore, in contrast to CABG, GIK therapy in patients undergoing PCI might be associated with more complications rather than protective effects. |
10,441 | Predictive value of left atrial deformation on prognosis in severe primary mitral regurgitation. | Impaired left atrial (LA) deformation is noted in patients with severe primary mitral regurgitation (MR), but its prognostic value is unknown. The aim of this study was to investigate the prognostic significance of LA deformation parameters in patients with chronic severe primary MR.</AbstractText>A total of 104 patients with asymptomatic chronic severe primary MR (Carpentier type II) and preserved left ventricular systolic function were prospectively recruited. Global peak positive strain of the left atrium (LASp) and strain rate in the LA filling phase (LASRr) as well as strain rate in the LA conduit phase were identified using two-dimensional speckle-tracking echocardiography.</AbstractText>During a mean follow-up period of 13.2 ± 9.5 months, 22 patients reached a composite end point of death and mitral valve repair or replacement prompted by heart failure development. Among the clinical and echocardiographic parameters, LV end-systolic volume index (19.5 ± 9.5 vs 15.7 ± 6.3 mL/m(2), P = .028), LASp (22.7 ± 10.4% vs 27.2 ± 9.1%, P = .049), and LASRr (1.97 ± 0.6 vs 2.33 ± 0.6 1/sec, P = .013) varied between the two groups in terms of end points but not age, LA volume index, left ventricular ejection fraction, pulmonary artery systolic pressure, and presence of atrial fibrillation. After multivariate analysis, low LASp (odds ratio, 3.606; 95% CI, 1.294-10.052; P = .014) and low LASRr (odds ratio, 2.857; 95% CI, 1.078-7.572; P = .035) remained powerful outcome indicators.</AbstractText>In patients with asymptomatic severe primary MR, reduced LASp and LASRr predicted a worse prognosis. These findings may offer additional information to guide early surgery.</AbstractText>Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,442 | Shen-Fu Injection () alleviates post-resuscitation myocardial dysfunction by up-regulating expression of sarcoplasmic reticulum Ca(2+)-ATPase. | To compare the effect of Shen-Fu Injection (SFI) and epinephrine on the expression of sarcoplasmic reticulum Ca(2+) ATPase 2a (SERCA2a) in a pig model with post-resuscitation myocardial dysfunction.</AbstractText>Ventricular fibrillation (VF) was electrically induced in Wu-zhi-shan miniature pigs. After 8 min of untreated VF and 2 min of cardiopulmonary resuscitation (CPR), all animals were randomly administered a bolus injection of saline placebo (SA group, n=10), SFI (0.8 mg/kg, SFI group, n=10) or epinephrine (20 μg/kg, EPI group, n=10). After 4 min of CPR, a 100-J shock was delivered. If the defibrillation attempt failed to attain restoration of spontaneous circulation (ROSC), manual chest compressions were rapidly resumed for a further 2 min followed by a second defibrillation attempt. Hemodynamic variables were recorded, and plasma concentrations of catecholamines were measured. Adenylate cyclase (AC), cyclic adenosine monophosphate (cAMP) and the expressions of β1-adrenoceptor (AR) and SERCA 2a were determined.</AbstractText>Cardiac output, left ventricular dp/dtmax and negative dp/dtmax were significantly higher in the SFI group than in the SA and EPI groups at 4 and 6 h after ROSC. The expression of β1-AR and SERCA2a at 24 h after ROSC were significantly higher in the SFI group than in the SA and EPI groups (P<0.05 or P<0.01).</AbstractText>The administration of epinephrine during CPR decreased the expression of SERCA2a and aggravated postresuscitation myocardial function (P<0.01). SFI attenuated post-resuscitation myocardial dysfunction, and the mechanism might be related to the up-regulation of SERCA2a expression.</AbstractText> |
10,443 | Clinical Outcomes in Cardiac Arrest Patients Following Prehospital Treatment with Therapeutic Hypothermia. | Recent studies have brought to question the efficacy of the use of prehospital therapeutic hypothermia for victims of out-of-hospital cardiac arrest (OHCA). Though guidelines recommend therapeutic hypothermia as a critical link in the chain of survival, the safety of this intervention, with the possibility of minimal treatment benefit, becomes important. Hypothesis/Problem This study examined prehospital therapeutic hypothermia for OHCA, its association with survival, and its complication profile in a large, metropolitan, fire-based Emergency Medical Services (EMS) system, where bystander cardiopulmonary resuscitation (CPR) and post-arrest care are in the process of being optimized.</AbstractText>This evaluation was a retrospective chart review of all OHCA patients with return of spontaneous circulation (ROSC) treated with therapeutic hypothermia, from January 1, 2013 through November 30, 2013. The primary outcomes were the proportion of patients with initiation of prehospital therapeutic hypothermia with survival to hospital admission, the proportion of patients with initiation of prehospital therapeutic hypothermia with survival to hospital discharge, and the complication profile of therapeutic hypothermia in this population. The complication profile included several clinical, radiographic, and laboratory parameters. Exclusion criteria included: no prehospital therapeutic hypothermia initiation; no ROSC; and age of 17 year old or younger.</AbstractText>Fifty-one post-cardiac arrest patients were identified that met inclusion criteria. The mean age was 61 years (SD=14.7 years), and 33 (72%) were male. The initial rhythm was ventricular fibrillation or pulseless ventricular tachycardia in 17 (37%) patients, and bystander CPR was performed in 28 (61%) patients with ROSC. Thirty-nine (85%) patients survived to hospital admission. Twenty-one patients (48%; 95% CI, 33-64) were administered vasopressors, 10 patients (24%; 95% CI, 10-37) were administered diuretics, and 19 patients (44%; 95% CI, 29-60) were administered antibiotics. Initial chest radiograph (CXR) findings were normal in 12 (29%) patients. Overall, 13 (28%; 95% CI, 15-42) study patients survived to hospital discharge.</AbstractText>Recent reports have questioned the efficacy and safety of prehospital therapeutic hypothermia. In this evaluation, in the setting of unstandardized post-arrest care, 85% of the patients survived to hospital admission and 28% survived to hospital discharge, with a complication profile which was similar to that noted in other studies. This suggests that further evidence may be needed before EMS systems stop administering therapeutic hypothermia to appropriately selected patients. In less-optimized systems, therapeutic hypothermia may still be an essential link in the chain of survival.</AbstractText> |
10,444 | Ventricular fibrillation by anaphylaxis following consumption of blue_skinned fish. | Approximately 4_h after eating mackerel sushi, a 65_year_old man developed generalized itchiness and redness, after which he became unresponsive. He went into a state of ventricular fibrillation but after he was defibrillated twice, his heartbeat returned. The electrocardiogram obtained immediately after hospitalization showed some ST_segment depression, but a subsequent electrocardiogram showed improvement. Coronary CT showed no obvious stenosis or plaque in the coronary artery.</AbstractText>Results of an IgE_RAST test confirmed that the level of allergen_specific IgE for mackerel measured <0.10_UA/mL, while the level for anisakis was 1.91_UA/mL.</AbstractText>As for the mechanism leading to cardiac arrest, it is thought that the histamines and leukotrienes released from cardiac mast cells caused a coronary artery spasm (Kounis syndrome). This anaphylactic shock is considered to be a result of anisakis allergy, but in general cases of anaphylaxis resulting from consumption of blue_skinned fish.</AbstractText> |
10,445 | High Frequency of Early Repolarization and Brugada-Type Electrocardiograms in Hypercalcemia. | J wave, or early repolarization has recently been associated with an increased risk of lethal arrhythmia and sudden death, both in idiopathic ventricular fibrillation and in the general population. Hypercalcemia is one of the causes of J point and ST segment elevation, but the relationship has not been well studied. The aim of this study was to examine the effects of hypercalcemia on J point elevation.</AbstractText>Electrocardiographic findings were compared in 89 patients with hypercalcemia and 267 age- and sex-matched healthy controls with normocalcemia. The association of J point elevation with arrhythmia events in patients with hypercalcemia was also studied.</AbstractText>The PR interval and the QRS duration were longer in patients with hypercalcemia than in normocalcemic controls. Both the QT and the corrected QT intervals were shorter in patients with hypercalcemia compared with normocalcemic controls. Conduction disorders, ST-T abnormalities, and J point elevation were more common in patients with hypercalcemia than normocalcemic controls. Following the resolution of hypercalcemia, the frequency of J point elevation decreased to a level similar to that noted in controls. During hospitalization, no arrhythmia event occurred in patients with hypercalcemia.</AbstractText>Hypercalcemia was associated with J point elevation.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,446 | Significance of electrocardiogram recording in high intercostal spaces in patients with early repolarization syndrome. | Published reports regarding inferolateral early repolarization (ER) syndrome (ERS) before 2013 possibly included patients with Brugada-pattern electrocardiogram (BrP-ECG) recorded only in the high intercostal spaces (HICS). We investigated the significance of HICS ECG recording in ERS patients.</AbstractText>Fifty-six patients showing inferolateral ER in the standard ECG and spontaneous ventricular fibrillation (VF) not linked to structural heart disease underwent drug provocation tests by sodium channel blockade with right precordial ECG (V1-V3) recording in the 2nd-4th intercostal spaces. The prevalence and long-term outcome of ERS patients with and without BrP-ECG in HICS were investigated. After 18 patients showing type 1 BrP-ECG in the standard ECG were excluded, 38 patients (34 males, mean age; 40.4 ± 13.6 years) were classified into four groups [group A (n = 6;16%):patients with ER and type 1 BrP-ECG only in HICS, group B (n = 5;13%):ERS with non-type 1 BrP-ECG only in HICS, group C (n = 8;21%):ERS with non-type 1 BrP-ECG in the standard ECG, and group D (n = 19;50%):ERS only, spontaneously or after drug provocation test]. During follow-up of 110.0 ± 55.4 months, the rate of VF recurrence including electrical storm was significantly higher in groups A (4/6:67%), B (4/5:80%), and C (4/8:50%) compared with D (2/19:11%) (A, B, and C vs. D, P < 0.05).</AbstractText>Approximately 30% of the patients with ERS who had been diagnosed with the previous criteria showed BrP-ECG only in HICS. Ventricular fibrillation mostly recurred in patients showing BrP-ECG in any precordial lead including HICS; these comprised 50% of the ERS cohort.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
10,447 | [The ECG of athletes]. | There has been a long standing controversy on the role of a resting electrocardiogram (ECG) in the preparticipation examination of athletes, as well as in children and adolescents, in leisure time and competitive athletes. Besides other arguments, this was due to the limited validity, which led to false positive and false negative findings.</AbstractText>Recent studies from different research groups yielded a significant improvement in establishing ECG criteria in athletes to discriminate normal from abnormal or pathological findings in athletes. This is additionally supported and improved by a software-based ECG device considering the new Seattle criteria. These new criteria from the Seattle conference reliably discriminate normal from abnormal findings. Frequent ECG findings in athletes, especially in those engaged in endurance sports are sinus bradycardia, atrioventricular (AV) block and signs of left ventricular hypertrophy.</AbstractText>Abnormal findings are related to structural left ventricular alterations due to cardiomyopathy, mainly hypertrophic with or without outflow tract obstruction, arrhythmogenic right ventricular cardiomyopathy (ARVC) and dilated cardiomyopathy. The ECG findings suggestive of electrical conductance disorders are observed in channelopathies, Wolff-Parkinson-White (WPW) syndrome supraventricular arrhythmias or disturbances of cardiac conduction. The main diseases are long or short QT syndrome, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia. Atrial fibrillation, mostly paroxysmal, is also now more frequently observed especially in middle aged endurance athletes.</AbstractText>Interpretation of ECG in young and older athletes requires in-depth knowledge in cardiology and sports medicine. The interpretation can only be carried out by considering medical history, clinical examination and ethnicity. Profound and long-term experience of athlete's ECG interpretation is required to protect athletes and to prevent cardiac emergencies.</AbstractText> |
10,448 | Rate control versus rhythm control in atrial fibrillation: lessons learned from clinical trials of atrial fibrillation. | Ample evidence supports the statement that in patients with atrial fibrillation in whom treatment is warranted, either rhythm control or rate control are acceptable primary therapeutic options. If a rhythm control strategy is chosen, it is important to consider that recurrence of atrial fibrillation is not treatment failure per se. Occasional recurrence, with cardioversion if necessary, may be quite acceptable. The latter will depend on the frequency, duration and symptoms associated with recurrence, and may require a change in the rhythm control therapy, e.g., change the antiarrhythmic drug, or initiate or redo atrial fibrillation ablation. And a rhythm control strategy should include careful attention to and treatment of comorbidities (hypertension, heart failure, diabetes, etc.). If a rate control strategy is chosen, treatment with a beta blocker or nondihydropyridine calcium channel blocker is almost always required to achieve adequate rate control. Digoxin is often useful to obtain satisfactory rate control in combination with a beta blocker or nondihydropyridine calcium channel blocker. Digoxin may be useful as primary therapy in the presence of hypotension or heart failure. Satisfactory ventricular rate control is usually a resting rate less than 110 beats per minute, although resting rates below 90 beats per minute are probably wiser. Finally, when pursuing a rhythm control strategy, because recurrence of atrial fibrillation is common, rate control therapy should be a part of the treatment regimen. |
10,449 | Iron-Sensitive Cardiac Magnetic Resonance Imaging for Prediction of Ventricular Arrhythmia Risk in Patients With Chronic Myocardial Infarction: Early Evidence. | Recent canines studies have shown that iron deposition within chronic myocardial infarction (CMI) influences the electric behavior of the heart. To date, the link between the iron deposition and malignant ventricular arrhythmias in humans with CMI is unknown.</AbstractText>Patients with CMI (n=94) who underwent late-gadolinium-enhanced cardiac magnetic resonance imaging before implantable cardioverter-defibrillator implantation for primary and secondary preventions were retrospectively analyzed. The predictive values of hypointense cores (HIC) in balanced steady-state free precession images and conventional cardiac magnetic resonance imaging and ECG malignant ventricular arrhythmia parameters for the prediction of primary combined outcome (appropriate implantable cardioverter-defibrillator therapy, survived cardiac arrest, or sudden cardiac death) were studied. The use of HIC within CMI on balanced steady-state free precession as a marker of iron deposition was validated in a canine MI model (n=18). Nineteen patients met the study criteria with events occurring at a median of 249 (interquartile range of 540) days after implantable cardioverter-defibrillator placement. Of the 19 patients meeting the primary end point, 18 were classified as HIC+, whereas only 1 was HIC-. Among the cohort in whom the primary end point was not met, there were 28 HIC+ and 47 HIC- patients. Receiver operating characteristic curve analysis demonstrated an additive predictive value of HIC for malignant ventricular arrhythmias with an increased area under the curve of 0.87 when added to left ventricular ejection fraction (left ventricular ejection fraction alone, 0.68). Both cardiac magnetic resonance imaging and histological validation studies performed in canines demonstrated that HIC regions in balanced steady-state free precession images within CMI likely result from iron depositions.</AbstractText>Hypointense cores within CMI on balanced steady-state free precession cardiac magnetic resonance imaging can be used as a marker of iron deposition and yields incremental information toward improved prediction of malignant ventricular arrhythmias.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,450 | ["Stressful holiday" - takotsubo cardiomyopathy]. | Takotsubo cardiomyopathy (TTC) is an acute syndrome characterized by rapid onset of transient systolic dysfunction of the left ventricle. Symptoms, ECG and laboratory findings resemble acute coronary syndrome, from which TTC differs by the absence of coronary artery disease. In typical cases, TTC is triggered by exposure to unexpected stress and the clinical course and prognosis are very good. We present a case of a 63-year-old woman, in whom the onset of the disease was complicated by ventricular fibrillation. The patient recovered without sequelae thanks to immediate cardiopulmonary resuscitation and following care in a specialized cardiocenter, which involved also implantation of implantable cardioverter defibrillator to prevent sudden cardiac death. Takotsubo cardiomyopathy is an important entity in the differential diagnosis of acute coronary syndrome. Despite very good prognosis in most cases it should not be underestimated and it deserves careful attention and treatment which can prevent harmful complications.Key words: myocardial infarction - sudden cardiac death - takotsubo cardiomyopathy - ventricular fibrillation. |
10,451 | Tachycardia-bradycardia syndrome in a patient with atrial fibrillation: a case report. | An 83-year-old woman was scheduled for a second transurethral resection of a bladder tumor. The preoperative electrocardiogram evaluation revealed atrial fibrillation with a slow ventricular response (ventricular rate: 59 /min). After intravenous injection of 1% lidocaine 40 mg and propofol 60 mg, the ventricular rate increased to 113 beats/min and then fell rapidly to 27 beats/min. Blood pressure was 70/40 mmHg. Later an atrial fibrillation rhythm, with a ventricular rate of 100-130 beats/min, was observed together with a sinus pause and sinus rhythm with a ventricular rate of 40-50 beats/min. An external pacemaker was applied and set at 60 mA, 40 counts. After the patient regained consciousness, she presented an alert mental state and had no chest symptoms. She was discharged 2 weeks later without complications after insertion of a permanent pacemaker. |
10,452 | Intermittent versus Persistent Wolff-Parkinson-White Syndrome in Children: Electrophysiologic Properties and Clinical Outcomes. | Intermittent Wolff-Parkinson-White (WPW) syndrome is considered to have a lower risk of sudden death. Fewer data exist regarding electrophysiologic (EP) characteristics and the natural history of intermittent WPW in children.</AbstractText>All patients with WPW age 1-18 years at a single institution (1996-2013) were reviewed. Patients with intermittent preexcitation were compared to those with loss of preexcitation on Holter/exercise testing and those with persistent preexcitation. High-risk accessory pathway (AP) was defined as AP effective refractory period (APERP), block cycle length, or shortest preexcited RR interval during atrial fibrillation ≤250 ms.</AbstractText>A total of 295 patients were included: 226 (76.6%) persistent, 39 (13.2%) intermittent, and 30 (10.2%) loss of preexcitation Holter/exercise. There were no differences in symptoms between groups. Median interquartile range APERP was significantly longer in intermittent WPW (380 [320, 488] ms vs 320 [300, 350] ms persistent, 310 [290, 330] ms loss of preexcitation Holter/exercise; P = 0.0008). At baseline, there was no difference between groups in frequency of high-risk pathways. However, when isoproterenol values were included, high-risk pathways were more frequent among patients with loss of preexcitation on Holter/exercise (54% vs 16% persistent, 11% intermittent; P = 0.005). There was one death in a patient with loss of preexcitation on exercise testing, no EP study, and prior drug use. A second patient with persistent WPW and APERP 270 ms required resuscitation following a methadone overdose.</AbstractText>Intermittent preexcitation in children does not connote a lower risk AP by EP criteria or reduced symptoms. The low number of pediatric WPW patients who develop preexcited atrial fibrillation or sudden death warrants larger studies to investigate these outcomes.</AbstractText>©2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,453 | Effects of a new antiarrhythmic drug SS-68 on electrical activity in working atrial and ventricular myocardium of mouse and their ionic mechanisms. | SS-68 is a derivative of indole, which demonstrated strong antiarrhythmic effects not associated with significant QT prolongation in dog models of atrial fibrillation. Therefore, SS-68 was proposed as a new antiarrhythmic drug and the present study is the first describing its effects on action potentials (APs) configuration and elucidating the ionic mechanisms of these effects. Sharp microelectrodes were used to record APs in isolated preparations of mouse atrial and ventricular myocardium. In both types of myocardium 10(-6) M SS-68 produced reduction of AP duration, 3 × 10(-6) M failed to alter AP waveform and 10(-5) - 3 × 10(-5) M prolonged APs. Sensitivity of main ionic currents to SS-68 was determined using whole-cell patch clamp. Transient potassium current Ito was slightly inhibited by SS-68 with IC50 = 1.43 × 10(-4) M. IKur was more sensitive with IC50 = 1.84 × 10(-5) M. Background inward rectifier showed very low sensitivity to SS-68 - only 10(-4) M SS-68 caused significant reduction of IK1. ICaL was significantly inhibited by 10(-6)M - 3 × 10(-5) M SS-68. The IC50 value for the ICaL was 1.84 × 10(-6) M. Thus, main ionic currents of mouse cardiomyocytes are inhibited by SS-68 in the following order of potency: ICaL > IKur > Ito > IK1. While lower concentration of SS-68 shorten APs via suppression of ICaL, higher concentrations inhibit K(+)-currents leading to APs prolongation. |
10,454 | Safety and efficacy of landiolol hydrochloride for prevention of atrial fibrillation after cardiac surgery in patients with left ventricular dysfunction: Prevention of Atrial Fibrillation After Cardiac Surgery With Landiolol Hydrochloride for Left Ventricular Dysfunction (PLATON) trial. | We previously conducted a prospective study of landiolol hydrochloride (INN landiolol), an ultrashort-acting β-blocker, and reported that it could prevent atrial fibrillation after cardiac surgery. This trial was performed to investigate the safety and efficacy of landiolol hydrochloride in patients with left ventricular dysfunction undergoing cardiac surgery.</AbstractText>Sixty patients with a preoperative left ventricular ejection fraction of less than 35% were randomly assigned to 2 groups before cardiac surgery and then received intravenous infusion with landiolol hydrochloride (landiolol group) or without landiolol (control group). The primary end point was occurrence of atrial fibrillation as much as 1 week postoperatively. The secondary end points were blood pressure, heart rate, intensive care unit and hospital stays, ventilation time, ejection fraction, biomarkers of ischemia, and brain natriuretic peptide.</AbstractText>Atrial fibrillation occurred in 3 patients (10%) in the landiolol group versus 12 (40%) in the control group, and its frequency was significantly lower in the landiolol group (P = .002). During the early postoperative period, levels of brain natriuretic peptide and ischemic biomarkers were significantly lower in the landiolol group than the control group. The landiolol group also had a significantly shorter hospital stay (P = .019). Intravenous infusion was not discontinued for hypotension or bradycardia in either group.</AbstractText>Low-dose infusion of landiolol hydrochloride prevented atrial fibrillation after cardiac surgery in patients with cardiac dysfunction and was safe, with no effect on blood pressure. This intravenous β-blocker seems useful for perioperative management of cardiac surgical patients with left ventricular dysfunction.</AbstractText>Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,455 | Association Between Chest Compression Interruptions and Clinical Outcomes of Ventricular Fibrillation Out-of-Hospital Cardiac Arrest. | Minimizing pauses in chest compressions during cardiopulmonary resuscitation is a focus of current guidelines. Prior analyses found that prolonged pauses for defibrillation (perishock pauses) are associated with worse survival. We analyzed resuscitations to characterize the association between pauses for all reasons and both ventricular fibrillation termination and patient survival.</AbstractText>In 319 patients with ventricular tachycardia/fibrillation out-of-hospital cardiac arrest, we analyzed recordings from all defibrillators used during resuscitation and measured durations of all cardiopulmonary resuscitation pauses. Median durations were 32 seconds (25th and 75th percentile, 22 and 52 seconds) for the longest pause for any reason, 23 seconds (25th and 75th percentile, 14 and 34 seconds) for the longest perishock pause, and 24 seconds (25th and 75th percentile, 11 and 38 seconds) for the longest nonshock pause. Multivariable regression models showed lower odds for survival per 5-second increase in the longest overall pause (odds ratio, 0.89; 95% confidence interval, 0.83-0.95), longest perishock pause (odds ratio, 0.85; 95% confidence interval, 0.77-0.93), and longest nonshock pause (odds ratio, 0.83; 95% confidence interval, 0.75-0.91). In 36% of cases, the longest pause was a nonshock pause; this subgroup had lower survival than the group in whom the longest pause was a perishock pause (27% versus 44%, respectively; P<0.01) despite a higher chest compression fraction. Preshock pauses were 8 seconds (25th and 75th percentile, 4 and 17 seconds) for shocks that terminated ventricular fibrillation and 7 seconds (25th and 75th percentile, 4 and 13 seconds) for shocks that did not (P=0.18).</AbstractText>Prolonged pauses have a negative association with survival not explained by chest compression fraction or decreased ventricular fibrillation termination rate. Ventricular fibrillation termination was not the mechanism linking pause duration and survival. Strategies shortening the longest pauses may improve outcome.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,456 | Left Ventricular Systolic Dysfunction by Longitudinal Strain Is an Independent Predictor of Incident Atrial Fibrillation: A Community-Based Cohort Study. | The increasing prevalence of atrial fibrillation (AF) represents a public health issue. Identifying new predictors of AF is therefore necessary to plan preventive strategies. We investigated whether left ventricular (LV) systolic dysfunction by global longitudinal strain (GLS), a predictor of cardiovascular events, may predict new-onset AF in a population setting.</AbstractText>Participants (n=675; mean age, 71±9 years; 60% women) in sinus rhythm from the population-based Northern Manhattan Study (NOMAS) underwent 2- and 3-dimensional echocardiography as part of the Cardiac Abnormalities and Brain Lesions (CABL) study. LV systolic function was assessed by LV ejection fraction and speckle-tracking GLS. During a mean follow-up of 63.6±18.7 months, 32 (4.7%) new confirmed cases of AF occurred. Lower GLS (adjusted hazard ratio/unit decrease, 1.22; 95% confidence interval, 1.04-1.43; P=0.015) and increased left atrial volume index (LAVi; adjusted hazard ratio/unit increase, 1.12; 95% confidence interval, 1.07-1.17; P<0.001) were significantly associated with incident AF, whereas LV ejection fraction was not (P=0.176). Abnormal GLS (>-14.7%) was associated with risk of new-onset AF with an adjusted hazard ratio of 3.2 (95% confidence interval, 1.4-7.5; P=0.007). The coexistence of abnormal GLS/abnormal LAVi was associated with a 28.6% incidence of AF (adjusted hazard ratio, 12.1; 95% confidence interval, 3.3-44.8; P<0.001) compared with participants with normal GLS/normal LAVi (AF incidence, 2.0%). AF incidence was intermediate in those with either abnormal GLS or abnormal LAVi (9.3% and 11.1%, respectively). GLS prognostic value for incident AF was incremental over risk factors and LAVi.</AbstractText>LV systolic dysfunction by GLS was a powerful and independent predictor of incident AF. GLS assessment may improve AF risk stratification in addition to established parameters.</AbstractText>© 2015 American Heart Association, Inc.</CopyrightInformation> |
10,457 | Ventricular Tachycardia and Early Fibrillation in Patients With Brugada Syndrome and Ischemic Cardiomyopathy Show Predictable Frequency-Phase Properties on the Precordial ECG Consistent With the Respective Arrhythmogenic Substrate. | Ventricular fibrillation (VF) has been proposed to be maintained by localized high-frequency sources. We tested whether spectral-phase analysis of the precordial ECG enabled identification of periodic activation patterns generated by such sources.</AbstractText>Precordial ECGs were recorded from 15 ischemic cardiomyopathy and 15 Brugada syndrome (type 1 ECG) patients during induced VF and analyzed in the frequency-phase domain. Despite temporal variability, induced VF episodes lasting 19.6±7.9 s displayed distinctly high power at a common frequency (shared frequency, 5.7±1.1 Hz) in all leads about half of the time. In patients with Brugada syndrome, phase analysis of shared frequency showed a V1-V6 sequence as would be expected from patients displaying a type 1 ECG pattern (P<0.001). Hilbert-based phases confirmed that the most stable sequence over the whole VF duration was V1-V6. Analysis of shared frequency in ischemic cardiomyopathy patients with anteroseptal (n=4), apical (n=3), and inferolateral (n=4) myocardial infarction displayed a sequence starting at V1-V2, V3-V4, and V5-V6, respectively, consistent with an activation origin at the scar location (P=0.005). Sequences correlated with the Hilbert-based phase analysis (P<0.001). Posterior infarction (n=4) displayed no specific sequence. On paired comparison, phase sequences during monomorphic ventricular tachycardia correlated moderately with VF (P<0.001). Moreover, there was a dominant frequency gradient from precordial leads facing the scar region to the contralateral leads (5.8±0.8 versus 5.4±1.1 Hz; P=0.004).</AbstractText>Noninvasive analysis of ventricular tachycardia and early VF in patients with Brugada syndrome and ischemic cardiomyopathy shows a predictable sequence in the frequency-phase domain, consistent with anatomic location of the arrhythmogenic substrate.</AbstractText>© 2015 The Authors.</CopyrightInformation> |
10,458 | Pregnancy-Associated Heart Failure: A Comparison of Clinical Presentation and Outcome between Hypertensive Heart Failure of Pregnancy and Idiopathic Peripartum Cardiomyopathy. | There is controversy regarding the inclusion of patients with hypertension among cases of peripartum cardiomyopathy (PPCM), as the practice has contributed significantly to the discrepancy in reported characteristics of PPCM. We sought to determine whether hypertensive heart failure of pregnancy (HHFP) (i.e., peripartum cardiac failure associated with any form of hypertension) and PPCM have similar or different clinical features and outcome.</AbstractText>We compared the time of onset of symptoms, clinical profile (including electrocardiographic [ECG] and echocardiographic features) and outcome of patients with HHFP (n = 53; age 29.6 ± 6.6 years) and PPCM (n = 30; age 31.5 ± 7.5 years). The onset of symptoms was postpartum in all PPCM patients, whereas it was antepartum in 85% of HHFP cases (p<0.001). PPCM was more significantly associated with the following features than HHFP (p<0.05): twin pregnancy, smoking, cardiomegaly with lower left ventricular ejection fraction on echocardiography, and longer QRS duration, QRS abnormalities, left atrial hypertrophy, left bundle branch block, T wave inversion and atrial fibrillation on ECG. By contrast, HHFP patients were significantly more likely (p<0.05) to have a family history of hypertension, hypertension and pre-eclampsia in a previous pregnancy, tachycardia at presentation on ECG, and left ventricular hypertrophy on echocardiography. Chronic heart failure, intra-cardiac thrombus and pulmonary hypertension were found significantly more commonly in PPCM than in HHFP (p<0.05). There were 5 deaths in the PPCM group compared to none among HHFP cases (p = 0.005) during follow-up.</AbstractText>There are significant differences in the time of onset of heart failure, clinical, ECG and echocardiographic features, and outcome of HHFP compared to PPCM, indicating that the presence of hypertension in pregnancy-associated heart failure may not fit the case definition of idiopathic PPCM.</AbstractText> |
10,459 | Effects of rotigaptide (ZP123) on connexin43 remodeling in canine ventricular fibrillation. | The present study investigated the effects of rotigaptide (ZP123) on the expression, distribution and phosphorylation of connexin43 (Cx43) in myocardial cell membranes in cardioversion of ventricular fibrillation (VF). A model of prolonged VF (8, 12 and 30 min) was established in mongrel dogs (n=8/group), following treatment with ZP123 or normal saline (NS control). A sham control was included. Cardiopulmonary resuscitation was begun at the start of VF followed by defibrillation. Animals received a maximum of three defibrillations of increasing energy (70, 100 and 150 J biphasic shock) as required. The average defibrillation energy, defibrillation success rate, return of spontaneous circulation and survival rate were recorded. Cx43 and phosphorylated (p-)Cx43 expression in cardiomyocyte membranes was detected by western blot and immunofluorescence analyses. Compared with the NS-treated control groups, the success defibrillation rate in the 8-min and 12-min ZP123 groups was significantly higher (P<0.05), while the average defibrillation energy was significantly lower (P<0.05). Cx43 expression in the VF groups was significantly lower than that in the sham control group (P<0.05). Cx43 expression was higher in the 12-min and 30-min ZP123 groups than that in the NS control group (P<0.05), while p-Cx43 expression decreased, although the levels were significantly higher than those in the control groups (P<0.05). Cx43 expression was positively correlated with the defibrillation success rate (r=0.91; P<0.01) and negatively with the mean defibrillation energy (r=-0.854; P<0.01), while p-Cx43 expression was positively correlated with the success rate of the previous three defibrillations (r=0.926; P<0.01).In conclusion, ZP123 reduced Cx43 remodeling through regulating the expression, distribution and phosphorylation of Cx43, thereby reducing the defibrillation energy required for successful cardioversion. |
10,460 | Upstream therapeutic strategies of Valsartan and Fluvastatin on Hypertensive patients with non-permanent Atrial Fibrillation (VF-HT-AF): study protocol for a randomized controlled trial. | Previous studies regarding rhythm control in patients with atrial fibrillation (AF) could not sufficiently demonstrate the efficacy of available anti-arrhythmic drugs. 'Upstream therapy' has emerged as a potential strategy for the prevention and treatment of AF. The use of angiotensin II receptor blockers and statins has been suggested to decrease new-onset AF, but which remains inadequately explored. This study was designed to examine whether valsartan or fluvastatin can reduce the risk of non-permanent AF in patients with hypertension.</AbstractText><AbstractText Label="METHODS/DESIGN" NlmCategory="METHODS">The VF-HT-AF study is a multicenter, randomized, open-label, four-arm parallel group study with comparative evaluation of valsartan and fluvastatin as upstream therapies for the treatment of non-permanent AF complicated by hypertension. The primary outcome measure is change in the development of paroxysmal AF into persistent or permanent AF, the development of persistent AF to permanent AF, and change in incidence of overall and persistent AF recurrence, as evaluated by 7-days ambulatory electrocardiograph monitoring (Holter) and patients' diaries during 2 years' follow-up. Secondary outcome measures of this study include the occurrence of: (1) fatal and nonfatal myocardial infarction; (2) heart failure (New York Heart Association stage III or IV); (3) cardiogenic shock; (4) serious bleeding necessitating hospitalization; (5) malignant ventricular arrhythmia; (6) revascularization therapy; (7) radiofrequency catheter ablation of AF; (8) changes of left atrial dimension, as measured by ultrasound echocardiography; (9) stroke; (10) cardiovascular mortality; and (11) all-cause mortality. A total of 1879 patients will be investigated from 15 medical centers throughout China to obtain the relevant information.</AbstractText>This is the first study in hypertensive patients complicated non-permanent AF in the Chinese population. Results of this study will inform the use of upstream therapies of AF.</AbstractText>chictr.org, ChiCTR-TRC-12002642.</AbstractText> |
10,461 | Inverse Correlation between the Atrial Fibrillatory Rate and the Ventricular Repolarization Time: Observations at Baseline and after an Intravenous Infusion of a Combined Potassium and Sodium Current Blocker. | The atrial fibrillatory rate (AFR) and the ventricular rate and repolarization (QTcF) were studied at baseline and under the influence of the combined potassium and sodium current blocker AZD7009.</AbstractText>Ninety-two patients with atrial fibrillation (AF) were randomized to an intravenous infusion of AZD7009 or placebo. The atrial fibrillatory activity in lead V1 was extracted using spatiotemporal QRST cancellation. The exponential decay (ED) characterized the degree of atrial signal organization.</AbstractText>The mean (SD) AFR at baseline was 396  ±  57 (range 253-584) and 410 ± 33 (range 363-469) bpm in patients randomized to AZD7009 and placebo, respectively. The AFR decreased within the first minutes of the AZD7009 infusion and reached its minimum of 235 ± 34 bpm after 18 minutes. On placebo, the AFR was unchanged. On AZD7009, the ED decreased from 1.2 ± 0.3 to reach its lowest level at 0.7 ± 0.2 after 14 minutes. The ventricular rate did not change significantly over time. The AFR was statistically significantly related to the ventricular repolarization at baseline, the QTcF being longer at lower AFR values, and this relationship remained during and after AZD7009. In the full multivariate linear regression model, including age, sex, left ventricular ejection fraction, QRS duration, heart rate, QTcF, AF episode duration, AF history duration, and right atrial or left atrial size, only QTcF and age were statistically significantly correlated with the AFR. The correlation remained when the uncorrected QT interval was used.</AbstractText>The QTcF was inversely correlated with AFR, both at baseline and during administration of AZD7009. The AFR was not correlated with the ventricular rate.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,462 | Atrial and ventricular tachyarrhythmias in military personnel. | Although rare, sudden cardiac death does occur in British military personnel. In the majority of cases, the cause is considered to be a malignant ventricular tachyarrhythmia, which can be precipitated by a number of underlying pathologies. Conversely, a tachyarrhythmia may have a more benign and treatable cause, yet the initial clinical symptoms may be similar, making differentiation difficult. This is an overview of the mechanisms underlying the initiation and propagation of arrhythmias and the various pathological conditions that predispose to arrhythmia genesis, classified according to which parts of the heart are involved: atrial tachyarrhythmias, atrial and ventricular, as well as those affecting the ventricles alone. It encompasses atrial tachycardia, atrial flutter, supraventricular tachycardias and ventricular tachycardias, including the more commonly encountered inherited primary electrical diseases, also known as the channelopathies. The clinical features, investigation and management strategies are outlined. The occupational impact-in serving military personnel and potential recruits-is described, with explanations relating to the different conditions and their specific implication on continued military service. |
10,463 | Ranolazine and its Antiarrhythmic Actions. | Ranolazine, a newly introduced, FDA-approved antianginal agent, has more recently been shown to have additional beneficial antiarrhythmic actions attributed to its inhibitory effect on both peak and late sodium current. The first clinical evidence of ranolazine's antiarrhythmic efficacy has been provided by the MERLIN-TIMI 36 trial, which showed that ranolazine may suppress both supraventricular and ventricular arrhythmias in patients with non-ST-segment elevation acute coronary syndrome. An interesting observation of available studies is that ranolazine seems to be more effective in pathological conditions, such as heart failure, ischemia, tachyarrhythmias or long QT3 syndrome, and has little effect on normal myocytes. Importantly, the drug may have an antiarrhythmic effect without causing proarrhythmia. The mechanisms involved in the antiarrhythmic action of ranolazine, experimental and clinical data for its antiarrhythmic efficacy in suppressing atrial fibrillation and ventricular tachyarrhythmias, are herein reviewed. Current data from small randomized trials indicate that further larger randomized controlled trials are needed that will examine the antiarrhythmic effects of ranolazine and its potential use in patients with arrhythmias. |
10,464 | Nitroglycerin administration during cardiac arrest caused by coronary vasospasm secondary to misoprostol. | There have been no reports of successful resuscitation using nitroglycerin (NTG) for cardiac arrest due to definitive coronary vasospasm. A 42-year-old female was brought to the Emergency Department in ventricular fibrillation after being found collapsed with the consumption of misoprostol. NTG, a potent coronary arterial dilator, not typically used in the management of cardiac arrest, was administered after 27 min of resuscitation efforts following advanced cardiac life support. NTG aided in the return of spontaneous circulation during a ventricular fibrillation cardiac arrest in the setting of prostaglandin use. <<b>Learning objective:</b> Nitroglycerin is not typically employed in the management of cardiac arrest. We report successful cardiac resuscitation after administration of intravenous nitroglycerin during a prolonged cardiac arrest event secondary to coronary artery vasospasm in the setting of recent misoprostol ingestion. Nitroglycerin may have a role in cardiac arrest in the setting of coronary vasospasm.>. |
10,465 | Herb-induced cardiotoxicity from accidental aconitine overdose. | Patients who overdose on aconite can present with life-threatening ventricular arrhythmia. Aconite must be prepared and used with caution to avoid cardiotoxic effects that can be fatal. We herein describe a case of a patient who had an accidental aconite overdose but survived with no lasting effects. The patient had prepared Chinese herbal medication to treat his pain, which resulted in an accidental overdose of aconite with cardiotoxic and neurotoxic effects. The patient had ventricular tachycardia, bidirectional ventricular tachycardia and ventricular fibrillation. Following treatment with anti-arrhythmic medications, defibrillation and cardiopulmonary resuscitation, he made an uneventful recovery, with no further cardiac arrhythmias reported. |
10,466 | Digitalis reappraised: Still here today, but gone tomorrow? | Digoxin is one of the oldest of drugs acting on the heart and still one of the most frequently used. While in atrial fibrillation digoxin continues to have a valid role in the control of ventricular rate when added to beta-blockers and calcium antagonists, digoxin for heart failure is no longer a supportable option in view of the negative recent meta-analysis. |
10,467 | Coronary microvascular function is independently associated with left ventricular filling pressure in patients with type 2 diabetes mellitus. | Left ventricular (LV) diastolic dysfunction is known as an early marker of myocardial alterations in patients with diabetes. Because microvascular disease has been regarded as an important cause of heart failure or diastolic dysfunction in diabetic patients, we tested the hypothesis that coronary flow reserve (CFR), which reflects coronary microvascular function, is associated with LV diastolic dysfunction in patients with type 2 diabetes.</AbstractText>We studied asymptomatic patients with type 2 diabetes but without overt heart failure. Transthoracic Doppler echocardiography was performed that included pulsed tissue Doppler of the mitral annulus and CFR of the left anterior descending artery (induced by adenosine 0.14 mg/kg/min). The ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/e') was used as a surrogate marker of diastolic function. We also evaluated renal function, lipid profile, parameters of glycemic control and other clinical characteristics to determine their association with E/e'. Patients with LV ejection fraction <50%, atrial fibrillation, valvular disease, regional wall motion abnormality, renal failure (serum creatinine >2.0 mg/dl) or type 1 diabetes were excluded. Patients with a CFR <2.0 were also excluded based on the suspicion of significant coronary artery stenosis.</AbstractText>We included 67 asymptomatic patients with type 2 diabetes and 14 non-diabetic controls in the final study population. In univariate analysis, age, presence of hypertension, LV mass index, estimated glomerular filtration rate and CFR were significantly associated with E/e'. Multivariate analysis indicated that both LV mass index and CFR were independently associated with E/e'. In contrast, there were no significant associations between parameters of glycemic control and E/e'.</AbstractText>CFR was associated with LV filling pressure in patients with type 2 diabetes. This result suggests a possible link between coronary microvascular disease and LV diastolic function in these subjects.</AbstractText> |
10,468 | Atrial-selective targeting of arrhythmogenic phase-3 early afterdepolarizations in human myocytes. | We have previously shown that non-equilibrium Na(+) current (INa) reactivation drives isoproterenol-induced phase-3 early afterdepolarizations (EADs) in mouse ventricular myocytes. In these cells, EAD initiation occurs secondary to potentiated sarcoplasmic reticulum Ca(2+) release and enhanced Na(+)/Ca(2+) exchange (NCX). This can be abolished by tetrodotoxin-blockade of INa, but not ranolazine, which selectively inhibits ventricular late INa.</AbstractText>Since repolarization of human atrial myocytes is similar to mouse ventricular myocytes in that it is relatively rapid and potently modulated by Ca(2+), we investigated whether similar mechanisms can evoke EADs in human atrium. Indeed, phase-3 EADs have been shown to re-initiate atrial fibrillation (AF) during autonomic stimulation, which is a well-recognized initiator of AF.</AbstractText>We integrated a Markov model of INa gating in our human atrial myocyte model. To simulate experimental results, we rapidly paced this cell model at 10Hz in the presence of 0.1μM acetylcholine and 1μM isoproterenol, and assessed EAD occurrence upon return to sinus rhythm (1Hz).</AbstractText>Cellular Ca(2+) loading during fast pacing results in a transient period of hypercontractility after return to sinus rhythm. Here, fast repolarization and enhanced NCX facilitate INa reactivation via the canonical gating mode (i.e., not late INa burst mode), which drives EAD initiation. Simulating ranolazine administration reduces atrial peak INa and leads to faster repolarization, during which INa fails to reactivate and EADs are prevented.</AbstractText>Non-equilibrium INa reactivation can critically contribute to arrhythmias, specifically in human atrial myocytes. Ranolazine might be beneficial in this context by blocking peak (not late) atrial INa.</AbstractText>Copyright © 2015 Elsevier Ltd. All rights reserved.</CopyrightInformation> |
10,469 | Prevalence of Atrial Fibrillation and Relation to Echocardiographic Parameters in a Healthy Asymptomatic Rural Korean Population. | Atrial fibrillation (AF) is the most common arrhythmia worldwide and a potent independent risk factor for stroke. This study aimed to determine the prevalence of AF in a population-based sample of adults in a rural region of Korea. Between January 2005 and December 2009, 4,067 individuals (60.2 ± 11.2 yr old, M: F = 1,582:2,485) over 21 who were residents of the county of Yangpyeong, Korea, participated in the study. AF was assessed on a resting 12-lead electrocardiogram (ECG) in 4,053 of the participants. Blood tests and transthoracic echocardiography (TTE) were also performed to investigate the relationship between left ventricular mass and AF in the study group. Fifty-four cases (32 men) were diagnosed as AF among the 4,053 subjects. The crude prevalence of AF was 1.3%. It was highest (2.3%) among sixty- and seventy- year olds, and higher in men than women in all age groups over 50. The prevalence in men was 2.0%, and in women 0.9%. In univariate analysis, age, male gender, body mass index, total serum cholesterol, alanine transaminase, serum creatinine, adiponectin level, and ischemic heart disease were associated with AF. Among the TTE parameters, systolic and diastolic left ventricular systolic internal dimension (LVID), and LV ejection fraction were associated with AF. In this relatively healthy population in a rural area of Korea, the prevalence of AF is 1.3%, and increases with age. Of the TTE parameters, systolic and diastolic LVID and left atrial diameter are related to prevalence of AF. |
10,470 | Human epicardial adipose tissue has a specific transcriptomic signature depending on its anatomical peri-atrial, peri-ventricular, or peri-coronary location. | Human epicardial adipose tissue (EAT) is a visceral and perivascular fat that has been shown to act locally on myocardium, atria, and coronary arteries. Its abundance has been linked to coronary artery disease (CAD) and atrial fibrillation. However, its physiological function remains highly debated. The aim of this study was to determine a specific EAT transcriptomic signature, depending on its anatomical peri-atrial (PA), peri-ventricular (PV), or peri-coronary location.</AbstractText>Samples of EAT and thoracic subcutaneous fat, obtained from 41 patients paired for cardiovascular risk factors, CAD, and atrial fibrillation were analysed using a pangenomic approach. We found 2728 significantly up-regulated genes in the EAT vs. subcutaneous fat with 400 genes being common between PA, PV, and peri-coronary EAT. These common genes were related to extracellular matrix remodelling, inflammation, infection, and thrombosis pathways. Omentin (ITLN1) was the most up-regulated gene and secreted adipokine in EAT (fold-change >12, P < 0.0001). Among EAT-enriched genes, we observed different patterns depending on adipose tissue location. A beige expression phenotype was found in EAT but PV EAT highly expressed uncoupled protein 1 (P = 0.01). Genes overexpressed in peri-coronary EAT were implicated in proliferation, O-N glycan biosynthesis, and sphingolipid metabolism. PA EAT displayed an atypical pattern with genes implicated in cardiac muscle contraction and intracellular calcium signalling pathway.</AbstractText>This study opens new perspectives in understanding the physiology of human EAT and its local interaction with neighbouring structures.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
10,471 | Comparison of Outcomes in Patients With Nonobstructive, Labile-Obstructive, and Chronically Obstructive Hypertrophic Cardiomyopathy. | Patients with nonobstructive hypertrophic cardiomyopathy (HC) are considered low risk, generally not requiring aggressive intervention. However, nonobstructive and labile-obstructive HC have been traditionally classified together, and it is unknown if these 2 subgroups have distinct risk profiles. We compared cardiovascular outcomes in 293 patients HC (96 nonobstructive, 114 labile-obstructive, and 83 obstructive) referred for exercise echocardiography and magnetic resonance imaging and followed for 3.3 ± 3.6 years. A subgroup (34 nonobstructive, 28 labile-obstructive, 21 obstructive) underwent positron emission tomography. The mean number of sudden cardiac death risk factors was similar among groups (nonobstructive: 1.4 vs labile-obstructive: 1.2 vs obstructive: 1.4 risk factors, p = 0.2). Prevalence of late gadolinium enhancement (LGE) was similar across groups but more non-obstructive patients had late gadolinium enhancement ≥20% of myocardial mass (23 [30%] vs 19 [18%] labile-obstructive and 8 [11%] obstructive, p = 0.01]. Fewer labile-obstructive patients had regional positron emission tomography perfusion abnormalities (12 [46%] vs nonobstructive 30 [81%] and obstructive 17 [85%], p = 0.003]. During follow-up, 60 events were recorded (36 ventricular tachycardia/ventricular fibrillation, including 30 defibrillator discharges, 12 heart failure worsening, and 2 deaths). Nonobstructive patients were at greater risk of VT/VF at follow-up, compared to labile obstructive (hazed ratio 0.18, 95% confidence interval 0.04 to 0.84, p = 0.03) and the risk persisted after adjusting for age, gender, syncope, family history of sudden cardiac death, abnormal blood pressure response, and septum ≥3 cm (p = 0.04). Appropriate defibrillator discharges were more frequent in nonobstructive (8 [18%]) compared to labile-obstructive (0 [0%], p = 0.02) patients. In conclusion, nonobstructive hemodynamics is associated with more pronounced fibrosis and ischemia than labile-obstructive and is an independent predictor of VT/VF in HC. |
10,472 | [Severe Caffeine Intentional Intoxication and Delayed Elimination: a Case Report]. | We report a massive intoxication by caffeine (20 g) with positive clinical evolution despite potentially lethal plasma concentrations (244 µg/mL) and delayed elimination. |
10,473 | Imaging of Ventricular Fibrillation and Defibrillation: The Virtual Electrode Hypothesis. | Ventricular fibrillation is the major underlying cause of sudden cardiac death. Understanding the complex activation patterns that give rise to ventricular fibrillation requires high resolution mapping of localized activation. The use of multi-electrode mapping unraveled re-entrant activation patterns that underlie ventricular fibrillation. However, optical mapping contributed critically to understanding the mechanism of defibrillation, where multi-electrode recordings could not measure activation patterns during and immediately after a shock. In addition, optical mapping visualizes the virtual electrodes that are generated during stimulation and defibrillation pulses, which contributed to the formulation of the virtual electrode hypothesis. The generation of virtual electrode induced phase singularities during defibrillation is arrhythmogenic and may lead to the induction of fibrillation subsequent to defibrillation. Defibrillating with low energy may circumvent this problem. Therefore, the current challenge is to use the knowledge provided by optical mapping to develop a low energy approach of defibrillation, which may lead to more successful defibrillation. |
10,474 | Optical Mapping of Ventricular Fibrillation Dynamics. | There is very limited information regarding the dynamic patterns of the electrical activity during ventricular fibrillation (VF) in humans. Most of the data used to generate and test hypotheses regarding the mechanisms of VF come from animal models and computer simulations and the quantification of VF patterns is non-trivial. Many of the experimental recordings of the dynamic spatial patterns of VF have been obtained from mammals using "optical mapping" or "video imaging" technology in which "phase maps" are derived from high-resolution transmembrane recordings from the heart surface. The surface manifestation of the unstable reentrant waves sustaining VF can be identified as "phase singularities" and their number and location provide one measure of VF complexity. After providing a brief history of optical mapping of VF, we compare and contrast a quantitative analysis of VF patterns from the heart surface for four different animal models, hence providing physiological insight into the variety of VF dynamics among species. We found that in all four animal models the action potential duration restitution slope was actually negative during VF and that the spatial dispersion of electrophysiological parameters were not different during the first second of VF compared to pacing immediately before VF initiation. Surprisingly, our results suggest that APD restitution and spatial dispersion may not be essential causes of VF dynamics. Analyses of electrophysiological quantities in the four animal models are consistent with the idea that VF is essentially a two-dimensional phenomenon in small rabbit hearts whose size are near the boundary of the "critical mass" required to sustain VF, while VF in large pig hearts is three-dimensional and exhibits the maximal theoretical phase singularity density, and thus will not terminate spontaneously. |
10,475 | Dental management of a patient fitted with subcutaneous Implantable Cardioverter Defibrillator device and concomitant warfarin treatment. | Automated Implantable Cardioverter Defibrillators (AICD), simply known as an Implantable Cardioverter Defibrillator (ICD), has been used in patients for more than 30 years. An Implantable Cardioverter Defibrillator (ICD) is a small battery-powered electrical impulse generator that is implanted in patients who are at a risk of sudden cardiac death due to ventricular fibrillation, ventricular tachycardia or any such related event. Typically, patients with these types of occurrences are on anticoagulant therapy. The desired International Normalized Ratio (INR) for these patients is in the range of 2-3 to prevent any subsequent cardiac event. These patients possess a challenge to the dentist in many ways, especially during oral surgical procedures, and these challenges include risk of sudden death, control of post-operative bleeding and pain. This article presents the dental management of a 60 year-old person with an ICD and concomitant anticoagulant therapy. The patient was on multiple medications and was treated for a grossly neglected mouth with multiple carious root stumps. This case report outlines the important issues in managing patients fitted with an ICD device and at a risk of sudden cardiac death. |
10,476 | Sleep apnea is associated with new-onset atrial fibrillation after coronary artery bypass grafting. | New-onset atrial fibrillation (AF) after coronary artery bypass grafting (CABG) remains a prevalent problem. We investigated the relationship between sleep apnea and new-onset post-CABG AF during inhospital stay.</AbstractText>We prospectively recruited 171 patients listed for an elective CABG for an overnight sleep study. Sleep apnea was defined as apnea-hypopnea index greater than or equal to 5.</AbstractText>Among the 160 patients who completed the study, those in the sleep apnea group (n=128; 80%) had larger left atrial diameter (40.4±5.4 vs 38.4±6.0 mm; P=.03) and left ventricular end-diastolic dimension (52.6±7.9 vs 49.2±6.8 mm; P=.03) than those in the non-sleep apnea group. The incidence of new-onset post-CABG AF was higher for the sleep apnea than non-sleep apnea groups (24.8% vs 9.7%; P=.07). There was 1 inhospital death and 2 patients with acute renal failure requiring dialysis after CABG in the sleep apnea group. None of the patients developed inhospital stroke. Multiple logistic regression analysis showed that sleep apnea was an independent predictor of post-CABG AF (odds ratio, 4.4; 95% confidence interval, 1.1-18.1; P=.04).</AbstractText>Sleep apnea is prevalent in patients undergoing CABG. It increases the susceptibility to new-onset AF after CABG, probably related to atrial and ventricular remodeling.</AbstractText>Copyright © 2015 Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,477 | Assessment of Risk Factors in Patients With Myocardial Infarction. | Coronary artery diseases (CAD) are one of the important health problems in the world, although considerable progresses have been made to decrease the mortality, they are still the first cause of death in many countries. Hence, the necessity of examining effective factors and risk factors on CAD can be one of the most important health priorities in many countries like Iran.</AbstractText>This study was performed to assess the risk factors in patients with myocardial infarction (MI) in Zahedan.</AbstractText><AbstractText Label="MATERIALS & METHODS" NlmCategory="METHODS">This is a cross sectional study in which 213 patients were examined. They had been diagnosed to have heart failure. Data gathering took 18 months. Data gathering tool was a designed checklist which was filled up by an experienced nurse during interview. Obtained results were recorded in files and analyzed in SPSS 21.</AbstractText>Results showed that 70% of patients were women and only 30% were men. 48% of them were illiterate and patients mean age was 58.3. SD had been 12.6. The mean of pain onset time till referring to hospital was 11 hours with SD of 2.1. 17% of patients (coronary artery diseases history), 25.5% (hypertension history), 26% (diabetes history), 15.5% (cholesterol history), 13% (smoking) and 3% have reported CABG history. The majority of people who referred had inferior MI (40.4%). 67.1% normal rhythm, 2.8% atrial fibrillation and 16% had ventricular tachycardia. Statistical tests showed a significant correlation between sex and the mean of referring time (p<0.05) but the relation between age and referring time was not significant.</AbstractText>Effective risk factors on MI were recognized in this study. Some of them such as age, sex and education cannot be modified but many are controllable such as hypertension, diabetes, cholesterol, and smoking and on time referring after pain onset. Having considered the results of this study health promotion for society and especially vulnerable people can be provided by omitting or reducing risk factors.</AbstractText> |
10,478 | An investigation of thrust, depth and the impedance cardiogram as measures of cardiopulmonary resuscitation efficacy in a porcine model of cardiac arrest. | Optimising the depth and rate of applied chest compressions following out of hospital cardiac arrest is crucial in maintaining end organ perfusion and improving survival. The impedance cardiogram (ICG) measured via defibrillator pads produces a characteristic waveform during chest compressions with the potential to provide feedback on cardiopulmonary resuscitation (CPR) and enhance performance. The objective of this pre-clinical study was to investigate the relationship between mechanical and physiological markers of CPR efficacy in a porcine model and examine the strength of correlation between the ICG amplitude, compression depth and end-tidal CO2 (ETCO2).</AbstractText>Two experiments were performed using 24 swine (12 per experiment). For experiment 1, ventricular fibrillation (VF) was induced and mechanical CPR commenced at varying thrusts (0-60 kg) for 2 min intervals. Chest compression depth was recorded using a Philips QCPR device with additional recording of invasive physiological parameters: systolic blood pressure, ETCO2, cardiac output and carotid flow. For experiment 2, VF was induced and mechanical CPR commenced at varying depths (0-5 cm) for 2 min intervals. The ICG was recorded via defibrillator pads attached to the animal's sternum and connected to a Heartsine 500 P defibrillator. ICG amplitude, chest compression depth, systolic blood pressure and ETCO2 were recorded during each cycle. In both experiments the within-animal correlation between the measured parameters was assessed using a mixed effect model.</AbstractText>In experiment 1 moderate within-animal correlations were observed between physiological parameters and compression depth (r=0.69-0.77) and thrust (r=0.66-0.82). A moderate correlation was observed between compression depth and thrust (r=0.75). In experiment 2 a strong within-animal correlation and moderate overall correlations were observed between ICG amplitude and compression depth (r=0.89, r=0.79) and ETCO2 (r=0.85, r=0.64).</AbstractText>In this porcine model of induced cardiac arrest moderate within animal correlations were observed between mechanical and physiological markers of chest compression efficacy demonstrating the challenge in utilising a single mechanical metric to quantify chest compression efficacy. ICG amplitude demonstrated strong within animal correlations with compression depth and ETCO2 suggesting its potential utility to provide CPR feedback in the out of hospital setting to improve performance.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
10,479 | Tricuspid Regurgitation Following Implantation of Endocardial Leads: Incidence and Predictors. | Endocardial leads, permanent pacemaker (PPM), or implantable cardioverter defibrillator (ICD) placed across the tricuspid valve can lead to tricuspid regurgitation (TR). The reported incidence of this complication has varied widely. There are limited data predicting which patients will develop this complication. This study sought to describe the incidence of worsening TR post-PPM or ICD and to identify patient-specific predictors of increased TR following lead placement.</AbstractText>Patients (N = 382) who received a PPM or ICD from January 1, 2006 to December 31, 2010 and had echocardiograms both within 365 days prior to and up to 1,200 days after device placement were studied. TR was assessed on a 6-point scale (none/trace, mild, mild to moderate, moderate, moderate to severe, severe). Primary outcome was a two-grade increase in the severity of TR. Echocardiographic and clinical predictors of worsening TR were examined using multivariate regression.</AbstractText>A two-grade increase in TR occurred in 10.0% of our patient population. Age, lead position, atrial fibrillation, right atrial (RA) area, right ventricular systolic pressure (RVSP), left atrial area, and severity of mitral regurgitation were univariate predictors of worsening TR post lead placement. In the multivariate analysis, predevice RA area and RVSP were associated with increased TR after endocardial lead placement. Percentage of time spent pacing did not appear to be associated with increased TR.</AbstractText>The incidence of increased TR postendocardial lead placement was 10.0%; this is lower than prior estimates. Predevice RA area and RVSP are predictors of increased TR after lead placement.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,480 | International Normalized Ratio Variability: A Measure of Anticoagulation Quality or a Powerful Mortality Predictor. | As atrial fibrillation (AF) carries twice the mortality hazard when compared with a similar population without diagnosed AF, the importance of risk stratifying is obvious. Several variables are related to outcome: age, comorbidities, and use of several medications, particularly oral anticoagulants. The CHA2DS2VASc score is an extremely useful tool to predict thromboembolic events and also mortality. The international normalized ratio (INR) variability is a treatment efficacy variable also associated with morbidity in patients receiving warfarin. The objective of the study is to compare the prognostic value of the CHA2DS2VASc versus the INR variability or its combination to predict mortality.</AbstractText>In this observational study, we analyzed 589 patients from our Atrial Fibrillation Cohort, all on warfarin for more than 1 year and had more than 5 INRs performed in the last 2 years. The CHA2DS2VASc, HAS-BLED, and SAMe-TT2R2 scores were calculated as well as the INR variability using the time-in-therapeutic-range (TTR), the percentage of INRs (%INRs) within range, and the standard deviation of the INRs (SDINRs). Kaplan-Meier survival curves were plotted via different cutoff points.</AbstractText>The mean TTR was 53 ± 23%; 34.6% of the patients had a TTR above 64%. The mean %INRs in range was 50.2 ± 20.2; 17.3% of the population had %INRs in range above 70%. The mean SDINRs was .84 ± .54, and 38.4% had SDINRs below .79. Of 598, 139 (22%) discontinued warfarin treatment. Death was responsible for almost 50% of treatment discontinuation. Of 598, 68 patients died during the study period (11.5 %); the most frequent causes of death were heart failure (30%), bleeding (17%), and ischemic stroke (15%). Patient survival had a correlation with TTR, %INRs in range, SDINRs, left ventricular ejection fraction, CHA2DS2VASc, and the combination of CHA2DS2VASc + SDINRs (cutoff >1 and >.79, respectively).</AbstractText>INR variability is an extremely useful tool to assess anticoagulation quality. Calculation of both CHA2DS2VASc and INR variability appears to be extremely useful to predict mortality in patients with AF receiving warfarin. The SDINRs emerges as a strong mortality predictor compared to the other INR variability indexes.</AbstractText>Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
10,481 | J wave pattern in unexplained syncope. | J wave pattern (JWP), characterized by J-point elevation in the anterolateral or inferior leads of the 12-lead electrocardiogram, has been associated with increased risk for idiopathic ventricular fibrillation and mortality. However, its prevalence in syncope of different etiologies is unknown and was evaluated in this study. The study sample comprised 170 consecutive patients with vasovagal syncope or syncope that remained unexplained after complete work-up. JWP in inferior leads and with a horizontal/descending ST-segment is more frequently found in subjects with unexplained syncope than in subjects with vasovagal syncope. This finding may be linked with worse prognosis of unexplained syncope. |
10,482 | ELECTRICAL INSTABILITY DUE TO REGIONAL INCREASE IN EXTRACELLULAR POTASSIUM ION CONCENTRATION. | Ventricular tachycardia and ventricular fibrillation are the two most dangerous arrhythmias. Both are related to reentrant electrical activity in the ventricles. Many studies of arrhythmias consider a homogeneous sheet of cardiac tissue. Since normal ventricular myocardium is inhomogeneous and inhomogeneities play an important role in the induction of reentry, we investigate the effect of a localized inhomogeniety developed at the border between normal and ischemic region.</AbstractText>We used the bidomain model to represent the electrical properties of cardiac tissue and a modified version of the dynamic Luo-Rudy (LRd) model to represent the active properties of the membrane. To investigate the effect of a localized inhomogeneity, the extracellular potassium [K]e</sub> concentration is raised to 10 mM from normal [K]e</sub> (4 mM) on the right half of the tissue.</AbstractText>A train of cathodal stimuli are applied from the lower left corner of the tissue with different basic cycle lengths (BCL). At certain BCL, the spatial heterogeneity created with regional elevation of [K]e</sub> can lead to action potential instability (alternans) in the normal and border regions, and 2:1 conduction block in the ischemic region. We observed the reentry when local heterogeneity in [K]e</sub> is changed from 10 to 12 mM on the right half of the virtual ventricular myocardium sheet.</AbstractText>Electrical alternans occur during high heart rates and are observed in patients suffering from ventricular tachycardia. It is an early indication of left ventricular systolic impairment. This study will help to evaluate alternans as a predictor and guide for antiarrhythmic therapy.</AbstractText> |
10,483 | Surgical Treatment of Concomitant Atrial Fibrillation: Focus onto Atrial Contractility. | Maze procedure aims at restoring sinus rhythm (SR) and atrial contractility (AC). This study evaluated multiple aspects of AC recovery and their relationship with SR regain after ablation.</AbstractText>122 mitral and fibrillating patients underwent radiofrequency Maze. Rhythm check and echocardiographic control of biatrial contractility were performed at 3, 6, 12, and 24 months postoperatively. A multivariate Cox analysis of risk factors for absence of AC recuperation was applied.</AbstractText>At 2-years follow-up, SR was achieved in 79% of patients. SR-AC coexistence increased from 76% until 98%, while biatrial contraction detection augmented from 84 to 98% at late stage. Shorter preoperative arrhythmia duration was the only common predictor of SR-AC restoring, while pulmonary artery pressure (PAP) negatively influenced AC recuperation. Early AC restoration favored future freedom from arrhythmia recurrence. Minor LA dimensions correlated with improved future A/E value and vice versa. Right atrial (RA) contractility restoring favored better left ventricular (LV) performance and volumes.</AbstractText>SR and left AC are two interrelated Maze objectives. Factors associated with arrhythmia "chronic state" (PAP and arrhythmia duration) are negative predictors of procedural success. Our results suggest an association between postoperative LA dimensions and "kick" restoring and an influence of RA contraction onto LV function.</AbstractText> |
10,484 | ISPD Cardiovascular and Metabolic Guidelines in Adult Peritoneal Dialysis Patients Part II - Management of Various Cardiovascular Complications. | Cardiovascular mortality has remained high in patients on peritoneal dialysis (PD) due to the high prevalence of various cardiovascular complications including coronary artery disease, left ventricular hypertrophy and dysfunction, heart failure, arrhythmia (especially atrial fibrillation), cerebrovascular disease, and peripheral arterial disease. In addition, nearly a quarter of PD patients develop sudden cardiac death as the terminal life event. Thus, it is essential to identify effective treatment that may lower cardiovascular mortality and improve survival of PD patients. The International Society for Peritoneal Dialysis (ISPD) commissioned a global workgroup in 2012 to formulate a series of recommendation statements regarding lifestyle modification, assessment and management of various cardiovascular risk factors, and management of the various cardiovascular complications to be published in 2 guideline documents. This publication forms the second part of the guideline documents and includes recommendation statements on the management of various cardiovascular complications in adult chronic PD patients. The documents are intended to serve as a global clinical practice guideline for clinicians who look after PD patients. We also define areas where evidence is clearly deficient and make suggestions for future research in each specific area. |
10,485 | Thoracolaparoscopic dissection of esophageal lymph nodes without esophagectomy is feasible in human cadavers and safe in a porcine survival study. | High-risk early esophageal adenocarcinoma (i.e. submucosal invasion >500 nm, poor differentiation, and/or presence of lymphovascular invasion) is currently treated with esophagectomy with lymph node (LN) dissection given the high rates of LN metastases. However, esophagectomy is associated with substantial morbidity and mortality. Endoscopic radical resection followed by thoracolaparoscopic LN dissection without concomitant esophagectomy could be an alternative. The study aim was to evaluate the feasibility and safety of thoracolaparoscopic dissection of esophageal LNs in a preclinical setting. (i) In human cadavers, thoracolaparoscopic dissection of LNs involved in drainage of the esophagus was performed. Subsequently, esophagectomy was performed to be able to detect retained LNs. Outcome parameters included the number of dissected LNs, the number of retained LNs in the esophagectomy specimen (ES), and technical success. (ii) In swine, thoracolaparoscopic LN dissection was also performed. After the procedure, the swine survived for 28 days. Thereafter, the swine were sacrificed and esophagectomy was performed. Outcome parameters included the presence of ischemia and/or stenosis in the ES and other complications. (i) In five human cadavers, a median of 26 LNs (interquartile range 22-46) were dissected. In two ES, one retained LN was found: one high paraesophageal, one low paraesophageal. Technical success rate was 100%. (ii) None of the seven porcine ES showed signs of ischemia or stenosis. One swine died because of ventricular fibrillation during surgery; during follow up no complications were observed. Thoracolaparoscopic dissection of LNs involved in the drainage of the esophagus is feasible in human cadavers and swine. The porcine survival study suggests that the esophageal vascularity is not severely compromised by the procedure. As anatomy differs between swine and humans, safety of the procedure will have to be investigated thoroughly before applying this new technique as the treatment of choice. |
10,486 | Electrocardiographic changes during induced therapeutic hypothermia in comatose survivors after cardiac arrest. | To assess the safety of therapeutic hypothermia (TH) concerning arrhythmias we analyzed serial electrocardiograms (ECG) during TH.</AbstractText>All patients recovered from a cardiac arrest with Glasgow < 9 at admission were treated with induced mild TH to 32-34 °C. TH was obtained with cool fluid infusion or a specific intravascular device. Twelve-lead ECG before, during, and after TH, as well as ECG telemetry data was recorded in all patients. From a total of 54 patients admitted with cardiac arrest during the study period, 47 patients had the 3 ECG and telemetry data available. ECG analysis was blinded and performed with manual caliper by two independent cardiologists from blinded copies of original ECG, recorded at 25 mm/s and 10 mm/mV. Coronary care unit staff analyzed ECG telemetry for rhythm disturbances. Variables measured in ECG were rhythm, RR, PR, QT and corrected QT (QTc by Bazett formula, measured in lead v2) intervals, QRS duration, presence of Osborn's J wave and U wave, as well as ST segment displacement and T wave amplitude in leads II, v2 and v5.</AbstractText>Heart rate went down an average of 19 bpm during hypothermia and increased again 16 bpm with rewarming (P < 0.0005, both). There was a non-significant prolongation of the PR interval during TH and a significant decrease with rewarming (P = 0.041). QRS duration significantly prolonged (P = 0.041) with TH and shortened back (P < 0.005) with rewarming. QTc interval presented a mean prolongation of 58 ms (P < 0.005) during TH and a significant shortening with rewarming of 22.2 ms (P = 0.017). Osborn or J wave was found in 21.3% of the patients. New arrhythmias occurred in 38.3% of the patients. Most frequent arrhythmia was non-sustained ventricular tachycardia (19.1%), followed by severe bradycardia or paced rhythm (10.6%), accelerated nodal rhythm (8.5%) and atrial fibrillation (6.4%). No life threatening arrhythmias (sustained ventricular tachycardia, polymorphic ventricular tachycardia or ventricular fibrillation) occurred during TH.</AbstractText>A 38.3% of patients had cardiac arrhythmias during TH but without life-threatening arrhythmias. A concern may rise when inducing TH to patients with long QT syndrome.</AbstractText> |
10,487 | Clinical Risk Stratification for Primary Prevention Implantable Cardioverter Defibrillators. | A conceptualized model may be useful for understanding risk stratification of primary prevention implantable cardioverter defibrillators considering the competing risks of appropriate implantable cardioverter defibrillator shock versus mortality.</AbstractText>In a prospective, multicenter, population-based cohort with left ventricular ejection fraction ≤35% referred for primary prevention implantable cardioverter defibrillator, we developed dual risk stratification models to determine the competing risks of appropriate defibrillator shock versus mortality using a Fine-Gray subdistribution hazard model. Among 7020 patients referred, 3445 underwent defibrillator implant (79.7% men, median, 66 years [25th, 75th: 58-73]). During 5918 person-years of follow-up, appropriate shock occurred in 204 patients (3.6 shocks/100 person-years) and 292 died (4.9 deaths/100 person-years). Competing risk predictors of appropriate shock included nonsustained ventricular tachycardia, atrial fibrillation, serum creatinine concentration, digoxin or amiodarone use, and QRS duration near 130-ms peak. One-year cumulative incidence of appropriate shock was 0.9% in the lowest risk category, and 1.7%, 2.5%, 4.9%, and 9.3% in low, intermediate, high, and highest risk groups, respectively. Hazard ratios for appropriate shock ranged from 4.04 to 7.79 in the highest 3 deciles (all P≤0.001 versus lowest risk). Cumulative incidence of 1-year death was 0.6%, 1.9%, 3.3%, 6.2%, and 17.7% in lowest, low, intermediate, high, and highest risk groups, respectively. Mortality hazard ratios ranged from 11.48 to 36.22 in the highest 3 deciles (all P<0.001 versus lowest risk).</AbstractText>Simultaneous estimation of risks of appropriate shock and mortality can be performed using clinical variables, providing a potential framework for identification of patients who are unlikely to benefit from prophylactic implantable cardioverter defibrillator.</AbstractText>© 2015 The Authors.</CopyrightInformation> |
10,488 | The effects of pentobarbital, ketamine-pentobarbital and ketamine-xylazine anesthesia in a rat myocardial ischemic reperfusion injury model. | To achieve reliable experimental data, the side-effects of anesthetics should be eliminated. Since anesthetics exert a variety of effects on hemodynamic data and incidence of arrhythmias, the selection of anesthetic agents in a myocardial ischemic reperfusion injury model is very important. The present study was performed to compare hemodynamic variables, the incidence of ventricular arrhythmias, and infarct size during 30 min of ischemia and 120 min of reperfusion in rats using pentobarbital, ketamine-pentobarbital or ketamine-xylazine anaesthesia. A total of 30 rats were randomly divided into three groups. In group P, pentobarbital (60 mg/kg, intraperitoneally [IP]) was used solely; in group K-P, ketamine and pentobarbital (50 and 30 mg/kg, respectively, IP) were used in combination; and in group K-X, ketamine and xylazine (75 and 5 mg/kg, respectively, IP) were also used in combination. Hemodynamic data and occurrence of ventricular arrhythmias were recorded throughout the experiments. The ischemic area was measured by triphenyltetrazolium chloride staining. The combination of ketamine-xylazine caused bradycardia and hypotension. The greatest reduction in mean arterial blood pressure during ischemia was in the P group. The most stability in hemodynamic parameters during ischemia and reperfusion was in the K-P group. The infarct size was significantly less in the K-X group. Whereas none of the rats anesthetized with ketamine-xylazine fibrillated during ischemia, ventricular fibrillation occurred in 57% of the animals anesthetized with pentobarbital or ketamine-pentobarbital. Because it offers the most stable hemodynamic parameters, it is concluded that the ketamine-pentobarbital anesthesia combination is the best anesthesia in a rat ischemia reperfusion injury model. |
10,489 | Wild-type transthyretin amyloidosis as a cause of heart failure with preserved ejection fraction. | Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous clinical syndrome with multiple underlying causes. Wild-type transthyretin (TTR) amyloidosis (ATTRwt) is an underdiagnosed cause of HFpEF that might benefit from new specific treatments. ATTRwt can be diagnosed non-invasively by (99m)Tc-3,3-diphosphono-1,2-propanodicarboxylic acid ((99m)Tc-DPD) scintigraphy. We sought to determine the prevalence of ATTRwt among elderly patients admitted due to HFpEF.</AbstractText>We prospectively screened all consecutive patients ≥60 years old admitted due to HFpEF [left ventricular (LV) ejection fraction ≥50%] with LV hypertrophy (≥12 mm). All eligible patients were offered a (99m)Tc-DPD scintigraphy. The study included 120 HFpEF patients (59% women, 82 ± 8 years). A total of 16 patients (13.3%; 95% confidence interval: 7.2-19.5) showed a moderate-to-severe uptake on the (99m)Tc-DPD scintigraphy. All patients with a positive scan underwent genetic testing of the TTR gene, and no mutations were found. An endomyocardial biopsy was performed in four patients, confirming ATTRwt in all cases. There were no differences in age, gender, hypertension, diabetes, coronary artery disease, or atrial fibrillation between ATTRwt patients and patients with other HFpEF forms. Although patients with ATTRwt exhibited higher median N-terminal pro-brain natriuretic peptide (6467 vs. 3173 pg/L; P = 0.019), median troponin I (0.135 vs. 0.025 µg/L; P < 0.001), mean LV maximal wall thickness (17 ± 3.4 vs. 14 ± 2.5 mm; P = 0.001), rate of pericardial effusion (44 vs. 19%; P = 0.047), and rate of pacemakers (44 vs. 12%; P = 0.004), clinical overlap between ATTRwt and other HFpEF forms was high.</AbstractText>ATTRwt is an underdiagnosed disease that accounts for a significant number (13%) of HFpEF cases. The effect of emerging TTR-modifying drugs should be evaluated in these patients.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
10,490 | Distribution of Ventricular Fibrosis Associated With Life-Threatening Ventricular Tachyarrhythmias in Patients With Nonischemic Dilated Cardiomyopathy. | Current guidelines recommend the implantation of an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden cardiac death (SCD) in a subgroup of patients with nonischemic cardiomyopathy (NICM) who have a left ventricular ejection fraction (LVEF) ≤ 30-35%, and are NYHA functional class II or III. However, the majority of patients with an ICD implantation for primary prevention did not receive appropriate ICD therapy. The purpose of this study was to evaluate the association between myocardial fibrosis detected by cardiovascular magnetic resonance (CMR) imaging and life-threatening ventricular arrhythmic events in NICM patients.</AbstractText>One hundred and seventy-five NICM patients with an LVEF ≦ 35 % and NYHA functional class II or III, (60 ± 15 years, LVEF 29 ± 5.4%) were studied. Myocardial fibrosis was identified with a late gadolinium enhancement (LGE) on CMR. Clinical events were defined as SCD or life-threatening ventricular arrhythmic events and were followed up for 5.1 ± 3.3 years.</AbstractText>The presence of an LGE was detected in 122 patients (70%). No life-threatening ventricular arrhythmia events occurred in patients with the absence of an LGE. A total of 18 ventricular tachycardia and 8 ventricular fibrillation events were found in patients with the presence of an LGE (P < 0.01). Sensitivity, specificity, and positive and negative predictive value of LGE in predicting life-threatening ventricular arrhythmia events were 100%, 34%, and 15% and 100%, respectively. Multivariate analysis showed that the presence of both septal and lateral mid-wall LGE was associated with life-threatening ventricular arrhythmic events (hazard ratio 23.1 CI; 2.88-184.9, P = 0.003).</AbstractText>The absence of an LGE predicts a low potential risk of SCD and life-threatening ventricular arrhythmia events in the near future. CMR may be a useful tool for selecting suitable patients for primary ICD implantations in NICM patients.</AbstractText>© 2015 Wiley Periodicals, Inc.</CopyrightInformation> |
10,491 | Genetics of Brugada syndrome. | The Brugada syndrome is characterized by unique 'coved-type' ST-segment elevation in the right precordial leads of electrocardiogram and ventricular fibrillation, and is responsible for 4 to 12% of sudden cardiac death in the general population. The frequency is higher in Southeast Asia including Japan compared with Western countries. Brugada syndrome is an inherited disease usually transmitted in an autosomal-dominant manner, and incomplete penetrance is frequently seen within affected families. To date, 20 genes have been associated with Brugada syndrome, but pathogenic mutations in the genes are identified in only about 30% of patients. The genetic background includes mutations in genes encoding sodium channel, calcium channels and potassium channels, as well as proteins affecting ion channels. Mutations in SCN5A, encoding the cardiac predominant sodium channel α-subunit, account for 20 to 30% of patients with Brugada syndrome and mutations in other genes only account for about 5% of patients. Furthermore, a recent genome-wide association study has identified new loci associated with the susceptibility of Brugada syndrome. |
10,492 | Combining Epinephrine and Esmolol Attenuates Excessive Autophagy and Mitophagy in Rat Cardiomyocytes After Cardiac Arrest. | Recent experimental and clinical studies have indicated that the β-adrenergic effect of epinephrine significantly increases the severity of postresuscitation myocardial dysfunction. The aim of this study was to investigate whether the short-acting β1-selective adrenergic blocking agent, esmolol, would impact postresuscitation autophagy and mitophagy in cardiomyocytes in a rat cardiac arrest (CA) model.</AbstractText>CA was induced in Sprague Dawley rats by epicardial ventricular fibrillation for 5 minutes. After successful resuscitation, the surviving rats were randomly divided into 2 groups that received femoral venous injections of epinephrine combined with either esmolol (EE group) or epinephrine (E group). Arterial blood samples were obtained at times 0, 30, and 180 minutes after return of spontaneous circulation. Surviving rats were euthanatized at 12 or 24 hours after return of spontaneous circulation, and the hearts were removed for histochemical analysis, electron microscopy, Western blotting, and TUNEL experiment.</AbstractText>Relative to the E group, the EE group had reduced N-Methyl-D-Aspartate receptors expression and reduced arterial lactate levels (P < 0.05), suggesting that epinephrine/esmolol can attenuate postresuscitation antioxidation and apoptosis. This protective effect also correlated with a reduction of excessive autophagy and mitophagy in the cardiomyocytes, as evidenced by a reduction in Beclin-1 and Parkin expression (P < 0.05).</AbstractText>Esmolol significantly alleviates postresuscitational autophagy, including mitophagy, and cardiomyocyte apoptosis in a rat CA model.</AbstractText> |
10,493 | Risk factors and clinical characteristics of in-hospital death in acute myocardial infarction with IABP support. | Despite the widespread use of the intra-aortic balloon pump (IABP) in acute myocardial infarction (AMI), there were few clinical trials regarding the deceased's feature. Therefore, we conducted a study to investigate the clinical characteristics and risk factor led to in-hospital deaths among AMI patients with IABP support.</AbstractText>To investigate the clinical characteristics and risk factors of in-hospital death with IABP support in AMI patients.</AbstractText>The clinical data of 572 consecutive IABP supported patients with AMI within 72 hours from symptom onset from July 2005 to July 2013 were retrospectively analyzed. The evolution of the risk factors of in-hospital death and clinical characteristics was compared in 81 non-survivors and the survivors.</AbstractText>Non-survivors had a more severe clinical profile at admission. Fewer patients were treated with emergency reperfusion therapy in the non-survivors group. Cardiogenic shock, Mechanical complications, ventricular tachycardia/fibrillation and MODS were much common in non-survivors (P<0.001). Multivariate logistic regression analysis showed advanced age (>65 years), prolonged time from symptom onset to first medical contact (FMC), Killip class III/IV, renal dysfunction(GFR <60 ml/min/1.73 m(2)), and left ventricular ejection fraction (LVEF) <30% were risk factors associated with higher in-hospital mortality.</AbstractText>IABP support may be more effective combined with revascularization for AMI patients whose hemodynamics is compromised. Patients accompanied with cardiogenic shock and other life-threatening complications are often uselesswith IABP support. Meanwhile, patient whose hemodynamics parameters have significant response to IABP may get benefits with IABP to improve in-hospital survival.</AbstractText> |
10,494 | Incidence and predictors of ischemic stroke during hospitalization for congestive heart failure. | Heart failure (HF) increases the risk of ischemic stroke. Data regarding the incidence and predictors of ischemic stroke during hospitalization for HF are limited. The study population of this retrospective cohort study consisted of patients with congestive HF, consecutively admitted to our center from October 2010 to April 2014. We excluded patients complicated with acute myocardial infarction, infective endocarditis, and takotsubo cardiomyopathy. We also excluded those with dialysis or mechanical circulatory support. We investigated the incidence of ischemic stroke during hospitalization for HF. Thereafter, we divided the patients without oral anticoagulants at admission into two groups: patients with ischemic stroke and those without it, and explored the predictors of ischemic stroke. A total of 558 patients (287 without atrial fibrillation (AF), 271 with AF) were enrolled. The mean age was 76.8 ± 12.3 years, and 244 patients (44 %) were female. The mean left-ventricular ejection fraction was 47.4 %. Oral anticoagulants were prescribed in 147 patients (8 without AF, 139 with AF). During hospitalization (median length 18 days), symptomatic ischemic stroke (excluding catheter-related) occurred in 15 patients (2.7 % of the total, 8 without AF, 7 with AF). Predictors significantly associated with increased risk of ischemic stroke in patients without oral anticoagulants were as follows; short-term increases in blood urea nitrogen after admission (at day 3; odds ratio (per 1 md/dl): 1.06, 95 % confidence interval (CI) 1.01-1.11, p = 0.02, and at day 7; odds ratio: 1.03, 95 % CI 1.00-1.07, p = 0.03, respectively), and previous stroke (odds ratio; 3.33, 95 % CI 1.01-11.00, p = 0.04). The incidence of ischemic stroke during hospitalization for HF was high, even in patients without AF. Previous stroke and short-term increases in blood urea nitrogen was significantly associated with the incidence of ischemic stroke. |
10,495 | Strain echocardiographic assessment of left atrial function predicts recurrence of atrial fibrillation. | We evaluated if a dispersed left atrial (LA) contraction pattern was related to atrial fibrillation (AF) in patients with normal left ventricular (LV) function, and normal or mildly enlarged left atrium.</AbstractText>We included 61 patients with paroxysmal AF (PAF). Of these, 30 had not while 31 had recurrence of AF after radiofrequency ablation (RFA). Twenty healthy individuals were included for comparison. Echocardiography was performed in patients in sinus rhythm the day before RFA. LA volume was calculated. Peak negative longitudinal strain was assessed in 18 LA segments during atrial systole. Contraction duration in 18 LA segments was measured as the time from peak of the P wave on electrocardiogram to maximum myocardial shortening in each segment. The standard deviation of contraction durations was defined as LA mechanical dispersion (LA MD). LA size was rather preserved in patients with PAF (LA volume 25 ± 10 mL/m(2)). LA MD was more pronounced in patients with recurrence of AF after RFA compared with those without recurrence and controls (38 ± 14 ms vs. 30 ± 12 ms vs. 16 ± 8 ms, both P < 0.001). LA MD was a predictor of PAF [OR 7.84 (95%CI 2.15-28.7), P < 0.01, per 10 ms increase] adjusted for age, LA volume, e', and LA function. LA function by strain was reduced in both patients with and without recurrent AF after RFA compared with controls (-14 ± 4% vs. -16 ± 3% vs. -19 ± 2%, both P < 0.05).</AbstractText>LA MD was pronounced, and LA deformation was reduced in patients with PAF with apparently normal LV structure and function, and normal or mildly enlarged LA. LA MD may be useful as a predictor of AF recurrence after RFA.</AbstractText>© The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.</CopyrightInformation> |
10,496 | Cardiovascular ultrasound exploration contributes to predict incident atrial fibrillation in arterial hypertension: the Campania Salute Network. | Interaction of cardiovascular (CV) risk factors with structural and hemodynamic alterations as combined promoters of atrial fibrillation (AF) is not yet well studied. We designed an observational, longitudinal, retrospective study to predict risk of incident AF by combination of CV risk profile, target organ damage and therapy in hypertensive patients.</AbstractText>We studied 7062 hypertensive patients without history of AF or prevalent CV disease, with ejection fraction (EF) of ≥50%, and no more than stage III chronic kidney disease. The patients were selected from an open registry, the Campania-Salute Network, collecting information from general practitioners and community hospitals, in the Campania Region, Southern Italy, networked with the Hypertension Center of Federico II University Hospital in Naples. The end-point of the present analysis was the detection of first episode of AF by ECG or hospital admission, at any point throughout follow-up (median 36months [IQR=10-74]). During follow-up, AF developed in 117 patients. Baseline older age, greater left atrial diameter (LAd), left ventricular mass (LVM), and intimal medial thickness (IMT) were independent predictors of AF (all p<0.0001), with no effect of CV risk factors. Beta-blockers and diuretics increased risk of incident AF; use of medications inhibiting renin-angiotensin system (RAS) reduced risk by 50% (all p<0.002).</AbstractText>Older age, increased LAd, and markers of target organ damage (increased LVM and IMT), identify the hypertensive phenotype at highest risk for AF. CV risk factors do not exhibit significant, independent association. Patients on anti-RAS therapy are exposed to lower risk of incident AF.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
10,497 | Improving Survival and Neurologic Function for Younger Age Groups After Out-of-Hospital Cardiac Arrest in Sweden: A 20-Year Comparison. | To describe changes in the epidemiology of out-of-hospital cardiac arrest in Sweden with the emphasis on the younger age groups.</AbstractText>Prospective observational study.</AbstractText>Sweden.</AbstractText>Patients were recruited from the Swedish Registry of Cardiopulmonary Resuscitation from 1990 to 2012. Only non-crew-witnessed cases were included.</AbstractText>Cardiopulmonary resuscitation.</AbstractText>The endpoint was 30-day survival. Cerebral function among survivors was estimated according to the cerebral performance category scores. In all, 50,879 patients in the survey had an out-of-hospital cardiac arrest, of which 1,321 (2.6%) were 21 years old or younger and 1,543 (3.0%) were 22-35 years old. On the basis of results from 2011 and 2012, we estimated that there are 4.9 cases per 100,000 person-years in the age group 0-21 years. The highest survival was found in the 13- to 21-year age group (12.6%). Among patients 21 years old or younger, the following were associated with an increased chance of survival: increasing age, male gender, witnessed out-of-hospital cardiac arrest, ventricular fibrillation, and a short emergency medical service response time. Among patients 21 years old or younger , there was an increase in survival from 6.2% in 1992-1998 to 14.0% in 2007-2012. Among 30-day survivors, 91% had a cerebral performance category score of 1 or 2 (good cerebral performance or moderate cerebral disability) at hospital discharge.</AbstractText>In Sweden, among patients 21 years old or younger, five out-of-hospital cardiac arrests per 100,000 person-years occur and survival in this patient group has more than doubled during the past two decades. The majority of survivors have good or relatively good cerebral function.</AbstractText> |
10,498 | Predictive factors of lead failure in patients implanted with cardiac devices. | Lead failures (LFs) are one of the most common complications in patients implanted with cardiovascular implantable electronic devices. LFs often cause serious secondary complications such as inappropriate ICD shocks or asystole. This study aimed to identify the clinical factors associated with the occurrence of LFs.</AbstractText>A total of 735 consecutive device implantations (mean age 67±15years, males 64%) performed at a single university hospital setting from 1997 to 2014 were included. The implanted devices consisted of 421 pacemakers, 250 implantable cardioverter defibrillators (ICD), 9 cardiac resynchronization therapy pacemakers (CRT-P), and 55 CRT defibrillators (CRT-D). The primary endpoint was the development of an LF.</AbstractText>During a mean duration of 5.8±4.3years, 38 LFs developed in 31 patients (mean age 56±14years). LFs included 32 ICD (7 Sprint Fidelis, 2 Riata), and 6 pacing leads. Nine patients received inappropriate ICD shocks and 1 had syncope due to an LF. All patients underwent lead reinsertions with device replacements. Eight patients required opposite site implantations due to venous occlusions. The predictive factors of LFs were the age, male sex, taller body length, ICD vs. pacemaker, lesser lead number, extra-thoracic puncture of the axillary vein vs. a cut-down of the cephalic vein, use of recalled leads and patients with idiopathic ventricular fibrillation (IVF) and Brugada syndrome (BrS).</AbstractText>LFs occurred mainly with ICD leads. A lesser age, the puncture method, lead model, and diagnosis of IVF/BrS were associated with the development of LFs.</AbstractText>Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
10,499 | Electrocardiographic abnormalities and cardiac arrhythmias in chronic obstructive pulmonary disease. | Chronic obstructive pulmonary disease (COPD) is independently associated with an increased burden of cardiovascular disease. Besides coronary artery disease (CAD) and congestive heart failure (CHF), specific electrocardiographic (ECG) abnormalities and cardiac arrhythmias seem to have a significant impact on cardiovascular prognosis of COPD patients. Disturbances of heart rhythm include premature atrial contractions (PACs), premature ventricular contractions (PVCs), atrial fibrillation (AF), atrial flutter (AFL), multifocal atrial tachycardia (MAT), and ventricular tachycardia (VT). Of note, the identification of ECG abnormalities and the evaluation of the arrhythmic risk may have significant implications in the management and outcome of patients with COPD. This article provides a concise overview of the available data regarding ECG abnormalities and arrhythmias in these patients, including an elaborated description of the underlying arrhythmogenic mechanisms. The clinical impact and prognostic significance of ECG abnormalities and arrhythmias in COPD as well as the appropriate antiarrhythmic therapy and interventions in this setting are also discussed. |
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