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13,500 | Glucagon-like peptide-1 preserves coronary microvascular endothelial function after cardiac arrest and resuscitation: potential antioxidant effects. | Glucagon-like peptide-1 (GLP-1) has protective effects in the heart. We hypothesized that GLP-1 would mitigate coronary microvascular and left ventricular (LV) dysfunction if administered after cardiac arrest and resuscitation (CAR). Eighteen swine were subjected to ventricular fibrillation followed by resuscitation. Swine surviving to return of spontaneous circulation (ROSC) were randomized to receive an intravenous infusion of either human rGLP-1 (10 pmol·kg(-1)·min(-1); n = 8) or 0.9% saline (n = 8) for 4 h, beginning 1 min after ROSC. CAR caused a decline in coronary flow reserve (CFR) in control animals (pre-arrest, 1.86 ± 0.20; 1 h post-ROSC, 1.3 ± 0.05; 4 h post-ROSC, 1.25 ± 0.06; P < 0.05). GLP-1 preserved CFR for up to 4 h after ROSC (pre-arrest, 1.31 ± 0.17; 1 h post-ROSC, 1.5 ± 0.01; 4 h post-ROSC, 1.55 ± 0.22). Although there was a trend toward improvement in LV relaxation in the GLP-1-treated animals, overall LV function was not consistently different between groups. 8-iso-PGF(2α), a measure of reactive oxygen species load, was decreased in post-ROSC GLP-1-treated animals [placebo, control (NS): 38.1 ± 1.54 pg/ml; GLP-1: 26.59 ± 1.56 pg/ml; P < 0.05]. Infusion of GLP-1 after CAR preserved coronary microvascular and LV diastolic function. These effects may be mediated through a reduction in oxidative stress. |
13,501 | Ventricular fibrillation conduction through an isthmus of preserved myocardium between radiofrequency lesions. | Selective local acceleration of myocardial activation during ventricular fibrillation (VF) contributes information on the interactions between neighboring zones during the arrhythmia. This study analyzes these interactions, centering the observations on an isthmus of myocardium between two radiofrequency (RF) lesions.</AbstractText>In nine isolated rabbit hearts, a gap of preserved myocardium was established between two RF lesions in the anterolateral left ventricle (LV) wall. Before, during, and after increasing the spatial heterogeneity of VF by local myocardial stretching, VF epicardial recordings were obtained.</AbstractText>Local stretch in the anterior LV wall decreased the excitable window (17 ± 7 ms vs 26 ± 7 ms; P < 0.05) and increased the dominant frequency (DFr; 18.9 ± 5.0 Hz vs 15.2 ± 3.6 Hz; P < 0.05) in this zone, without changes in the non-stretched posterolateral zone (25 ± 4 ms vs 27 ± 6 ms, ns and 14.1 ± 2.7 Hz vs 14.3 ± 3.0 Hz, ns). The DFr ratio at both sides of the gap was inversely correlated to the excitable window ratio (R = -0.57; P = 0.002). Before (31% vs 26%), during (29% vs 22%), and after stretch suppression (35% vs 25%), the wavefronts passing through the gap from the posterolateral to the anterior LV wall were seen to predominate. The number of wavefronts that passed from the anterior to the posterolateral LV wall was related to the excitable window in this zone (R = 0.41; P = 0.03).</AbstractText>The VF acceleration induced in the stretched zone does not increase the flow of wavefronts toward the non-stretched zone in the adjacent gap of preserved myocardium. The absence of significant changes in the electrophysiological parameters of the non-stretched myocardium limits the arrival of wavefronts in this zone.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,502 | Use of a noninvasive continuous monitoring device in the management of atrial fibrillation: a pilot study. | Outpatient ambulatory cardiac rhythm monitoring is a routine part of the management of patients with paroxysmal atrial fibrillation (AF). Current systems are limited by patient convenience and practicality.</AbstractText>We compared the Zio(®) Patch, a single-use, noninvasive waterproof long-term continuous monitoring patch, with a 24-hour Holter monitor in 74 consecutive patients with paroxysmal AF referred for Holter monitoring for detection of arrhythmias.</AbstractText>The Zio(®) Patch was well tolerated, with a mean monitoring period of 10.8 ± 2.8 days (range 4-14 days). Over a 24-hour period, there was excellent agreement between the Zio(®) Patch and Holter for identifying AF events and estimating AF burden. Although there was no difference in AF burden estimated by the Zio(®) Patch and the Holter monitor, AF events were identified in 18 additional individuals, and the documented pattern of AF (persistent or paroxysmal) changed in 21 patients after Zio(®) Patch monitoring. Other clinically relevant cardiac events recorded on the Zio(®) Patch after the first 24 hours of monitoring, including symptomatic ventricular pauses, prompted referrals for pacemaker placement or changes in medications. As a result of the findings from the Zio(®) Patch, 28.4% of patients had a change in their clinical management.</AbstractText>The Zio(®) Patch was well tolerated, and allowed significantly longer continuous monitoring than a Holter, resulting in an improvement in clinical accuracy, the detection of potentially malignant arrhythmias, and a meaningful change in clinical management. Further studies are necessary to examine the long-term impact of the use of the Zio(®) Patch in AF management.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,503 | Impact of Atrial Fibrillation On Cardiovascular Mortality in the Setting of Myocardial Infarction. | Atrial fibrillation (AF) commonly occurs in patient with acute myocardial infarction (AMI). Potential triggers for AF development in this setting includes reduced left ventricular function, advanced diastolic dysfunction and mitral regurgitation leading to elevated left atrial pressures and atrial stretch. Other triggering mechanisms include inflammation and atrial ischemia. Multiple studies have shown that AF in patients with is associated with increased mortality. However, whether AF is a risk marker or a causal mediator of death remains controversial. There is relative dearth of data with regard to optimal management of AF in the setting of acute coronary syndromes. Patients with AMI who develop AF are at increased risk of stroke. However, the issue of the most appropriate antithrombotic regimens is complex given the need to balance stroke prevention against recurrent coronary events or stent thrombosis and the risk of bleeding. Presently, 'triple therapy' consisting of dual antiplatelet agents plus oral anticoagulants for 3-6 months or longer has been recommended for patients at moderate-high risk of stroke. Atrial fibrillation (AF), the most common sustained arrhythmia seen in clinical practice, often coincides with acute myocardial infarction (AMI), with a reported incidence ranging between 7% and 21%.[1] The development of atrial fibrillation in the acute phase of AMI may aggravate ischemia and heart failure, lead to clinical instability and adversely affect outcome. In the following we will review the pathophysiology, clinical characteristics and importance, and management of AF occurring in the setting of AMI. |
13,504 | Omega-3 Polyunsaturated Fatty Acid Supplementation: Mechanism and Current Evidence in Atrial Fibrillation. | Atrial fibrillation (AF) is the most prevalent arrhythmia and is associated with considerable morbidity and mortality. Available pharmacologic antiarrhythmic therapies are often ineffective in preventing the recurrence of AF, possibly because these drugs target a single pathophysiological mechanism. Given their beneficial effects on ventricular arrhythmias, omega-3 polyunsaturated fatty acids (n-3 PUFAs) have recently been investigated as possible candidates in the treatment of supraventricular arrhythmias. In this review, we explore the current understanding of the antiarrhythmic effects attributed to n-3 PUFAs including direct modulation of ionic channels, improvement of membrane fluidity, anti-inflammatory and antifibrotic effects, and modulation of sympatho-vagal balance. We will then focus on the results of epidemiologic studies exploring the associations between nutritional intake of n3 PUFAs and the incidence of AF, and will review the findings of the clinical trials investigating the effects of n-3 PUFAs supplementation in the prophylaxis of AF and in the prevention of its recurrences. |
13,505 | Role of Left Ventricular Diastolic Dysfunction in Predicting Atrial Fibrillation Recurrence after Successful Electrical Cardioversion. | The role of left ventricular (LV) diastolic dysfunction in predicting atrial fibrillation (AF) recurrence after successful electrical cardioversion is largely unknown. Studies suggest that there may be a link between abnormal LV compliance and the initial development, and recurrence of AF after electrical cardioversion. Although direct-current cardioversion (DCCV) is a well-established and highly effective method to convert AF to sinus rhythm, it offers little else beyond immediate rate control because it does not address the underlying cause of AF. Preservation of sinus rhythm after successful cardioversion still remains a challenge for clinicians. Despite the use of antiarrhythmic drugs and serial cardioversions, the rate of AF recurrence remains high in the first year. Current evidence suggests that diastolic dysfunction, which is associated with atrial volume and pressure overload, may be a mechanism underlying the perpetuating cycle of AF recurrence following successful electrical cardioversion. Diastolic dysfunction is considered to be a defect in the ability of the myofibrils, which have shortened against a load in systole to eject blood into the high-pressure aorta, to rapidly or completely return to their resting length. Consequently, LV filling is impaired and the non-compliant left ventricle is unable to fill at low pressures. As a result, left atrial and pulmonary vein pressure rises, and electrical and structural remodeling of the atrial myocardium ensues, creating a vulnerable substrate for AF. In this article, we review the current evidence highlighting the association of LV diastolic dysfunction with AF recurrence after successful electrical cardioversion and provide an approach to the management of LV diastolic dysfunction to prevent AF recurrence. |
13,506 | Reversal of Dilated Cardiomyopathy After Successful Radio-Frequency Ablation of Frequent Atrial Premature Beats, a New Cause for Arrhythmia-Induced Cardiomyopathy. | Incessant atrial premature beats as a potential cause for tachycardia-induced cardiomyopathy was suspected in a patient presenting with dilated non-ischemic cardiomyopathy and severely altered left ventricular ejection fraction. The elimination of a left atrial focus by percutaneous RF ablation led to normalization of the clinical status, of atrial and ventricular dimensions and left ventricular systolic function. |
13,507 | Positive QRS complex in lead i as a malignant sign in right ventricular outflow tract tachycardia: comparison between polymorphic and monomorphic ventricular tachycardia. | Idiopathic ventricular fibrillation (VF) or polymorphic ventricular tachycardia (PVT) arising from the right ventricular outflow tract (RVOT) is occasionally observed. The difference in the initial ventricular premature contraction (VPC) between VF/PVT and monomorphic VT (MVT) from the RVOT, however, has not yet been fully investigated.</AbstractText>The electrocardiogram findings and the clinical characteristics were compared between 14 patients with PVT and 77 with MVT. The episodes of syncope were more frequent in the VF and/or PVT group (57%) than in the MVT group (10%). An initial VPC with a positive QRS complex in lead I was observed in 10 (71%) of 14 patients with VF/PVT, and in 27 (35%) of 77 patients with MVT (P<0.05). Although radiofrequency (RF) catheter ablation targeting the trigger VPC often produced a morphological change, VF/PVT was eliminated in 13 (93%) of 14 patients after additional RF applications.</AbstractText>Malignant arrhythmias from the RVOT, although rare, should be considered when the patient has a syncopal episode and VPC with a positive QRS complex in lead I.</AbstractText> |
13,508 | [Irbesartan in clinical practice]. | Irbesartan is a noncompetitive angiotensin II receptor type 1 antagonist which has been successfully used for more than 10 years for the treatment of hypertensive disease. In a dose of 150-300 mg/day irbesartan produces long term effect for 24 hours. Its antihypertensive efficacy is augmented by concomitant administration of hydrochlorothiazide. Irbesartan reduces left ventricular hypertrophy and increases probability of maintenance of sinus rhythm after cardioversion of atrial fibrillation. Renoprotective effects of irbesartan has been demonstrated both at early and late stages of kidney involvement in patients with type 2 diabetes. Therapeutic efficacy and safety of irbesartan ensure high level of patients compliance. Irbesartan as monotherapy or as combination with hydrochlorothiazide demonstrate contemporary therapeutic approach to arterial hypertension as well as to diabetic nephropathy both at its early and late stages. |
13,509 | [Noncompaction myocardium as a primary phenomenon or consequence of myocardial dysfunction: clinical masks of the syndrome]. | Noncompaction myocardium (NCM) is a genetic heterogeneous primary cardiomyopathy which affects both children and adults and can be either isolated or combined with other congenital heart disorders. It has common pathogenesis of symptoms but is distinguished by pronounced clinical polymorphism. We have observed 25 adult patients (15 men, 10 women aged from 20 to 62 years, mean age 42.9+/-13.3 years) with NCM syndrome. Heart failure have been found in 96% of patients (functional class [FC] I in 7, II - in 6, III in 7, and IV - in 4 patients). Ninety two percent of patients have ventricular extrasystoles, 32% - atrial fibrillation, 28% - FC I-III angina. Mean end diastolic left ventricular dimension is 6.5+/-0.8cm, ejection fraction 29.7+/-13.0%, mean pulmonary artery pressure - 42.6+/-13.5 mm Hg. Intracardiac thrombosis have been found in 24% of patients. In 7 patients morphological study of myocardium has been performed. NCM syndrome was diagnosed at initial investigation just in 1 case. We distinguished the following clinical masks (variants of diagnosis) of NCM: 1) clinically not manifest, is revealed at accidental examination (4%); 2) exists under mask of "idiopathic" rhythm disturbances (8%); 3) has a mask of ischemic heart disease; 4) is revealed in patients with acute or subacute myocarditis (12%); 5) has a mask of dilated cardiomyopathy (52%); 6) NCM in patients with other primary cardiomyopathies (hypertrophic, restrictive, genetic myopathy, arrhythmogenic right ventricular dysplasia). Combination of NCM with congenital heart defects has been found in 20% of patients. In 56% of cases myocarditis was diagnosed (it was viral in no less than 44%). Only in 32% of patients it is possible to consider presence of isolated NCM syndrome. This paper contains discussion of problems of diagnostics (including morphological) and treatment in the presented group of patients, significance of myocarditis for development of decompensation, role of NCM in patients with other primary cardiomyopathies, possibility of compensatory (secondary) character of NCM in severe systolic dysfunction. |
13,510 | Dissection of a quantitative trait locus for PR interval duration identifies Tnni3k as a novel modulator of cardiac conduction. | Atrio-ventricular conduction disease is a common feature in Mendelian rhythm disorders associated with sudden cardiac death and is characterized by prolongation of the PR interval on the surface electrocardiogram (ECG). Prolongation of the PR interval is also a strong predictor of atrial fibrillation, the most prevalent sustained cardiac arrhythmia. Despite the significant genetic component in PR duration variability, the genes regulating PR interval duration remain largely elusive. We here aimed to dissect the quantitative trait locus (QTL) for PR interval duration that we previously mapped in murine F2 progeny of a sensitized 129P2 and FVBN/J cross. To determine the underlying gene responsible for this QTL, genome-wide transcriptional profiling was carried out on myocardial tissue from 109 F2 mice. Expression QTLs (eQTLs) were mapped and the PR interval QTL was inspected for the co-incidence of eQTLs. We further determined the correlation of each of these transcripts to the PR interval. Tnni3k was the only eQTL, mapping to the PR-QTL, with an established abundant cardiac-specific expression pattern and a significant correlation to PR interval duration. Genotype inspection in various inbred mouse strains revealed the presence of at least three independent haplotypes at the Tnni3k locus. Measurement of PR interval duration and Tnni3k mRNA expression levels in six inbred lines identified a positive correlation between the level of Tnni3k mRNA and PR interval duration. Furthermore, in DBA/2J mice overexpressing hTNNI3K, and in DBA.AKR.hrtfm2 congenic mice, which harbor the AKR/J "high-Tnni3k expression" haplotype in the DBA/2J genetic background, PR interval duration was prolonged as compared to DBA/2J wild-type mice ("low-Tnni3k expression" haplotype). Our data provide the first evidence for a role of Tnni3k in controlling the electrocardiographic PR interval indicating a function of Tnni3k in atrio-ventricular conduction. |
13,511 | Ventricular arrhythmias in patients with implanted ventricular assist devices: a contemporary review. | Ventricular arrhythmia (VA) is a significant factor in the clinical management of patients with congestive heart failure (CHF). Understanding the implications of VA in ventricular assist device-supported CHF patients is critical to appropriate clinical decision making in this special population. This article details research findings on this topic, and attempts to link them to practical patient management strategies. |
13,512 | Intra-aortic balloon pump (ΙΑΒΡ): from the old trends and studies to the current "extended" indications of its use. | This report outlines the well defined indications of using IABP and also favours extending the indications of IABP use, to include not only "therapeutically" the aging unstable patients but also "prophylactically" patients with low EF or high Euroscore. |
13,513 | Chest compression-only cardiopulmonary resuscitation for out-of-hospital cardiac arrest with public-access defibrillation: a nationwide cohort study. | It remains unclear which is more effective to increase survival after out-of-hospital cardiac arrest in those with public-access defibrillation, bystander-initiated chest compression-only cardiopulmonary resuscitation (CPR) or conventional CPR with rescue breathing.</AbstractText>A nationwide, prospective, population-based observational study covering the whole population of Japan and involving consecutive out-of-hospital cardiac arrest patients with resuscitation attempts has been conducted since 2005. We enrolled all out-of-hospital cardiac arrests of presumed cardiac origin that were witnessed and received shocks with public-access automated external defibrillation (AEDs) by bystanders from January 1, 2005, to December 31, 2009. The main outcome measure was neurologically favorable 1-month survival. We compared outcomes by type of bystander-initiated CPR (chest compression-only CPR and conventional CPR with compressions and rescue breathing). Multivariable logistic regression was used to assess the relationship between the type of CPR and a better neurological outcome. During the 5 years, 1376 bystander-witnessed out-of-hospital cardiac arrests of cardiac origin in individuals who received CPR and shocks with public-access AEDs by bystanders were registered. Among them, 506 (36.8%) received chest compression-only CPR and 870 (63.2%) received conventional CPR. The chest compression-only CPR group (40.7%, 206 of 506) had a significantly higher rate of 1-month survival with favorable neurological outcome than the conventional CPR group (32.9%, 286 of 870; adjusted odds ratio, 1.33; 95% confidence interval, 1.03-1.70).</AbstractText>Compression-only CPR is more effective than conventional CPR for patients in whom out-of-hospital cardiac arrest is witnessed and shocked with public-access defibrillation. Compression-only CPR is the most likely scenario in which lay rescuers can witness a sudden collapse and use public-access AEDs.</AbstractText> |
13,514 | Ability to induce atrial fibrillation in the peri-operative period is associated with phosphorylation-dependent inhibition of TWIK protein-related acid-sensitive potassium channel 1 (TASK-1). | Peri-operative atrial fibrillation (peri-op AF) is a common complication following thoracic surgery. This arrhythmia is thought to be triggered by an inflammatory response and can be reproduced in various animal models. Previous work has shown that the lipid inflammatory mediator, platelet-activating factor (PAF), synthesized by activated neutrophils, can induce atrial and ventricular arrhythmias as well as repolarization abnormalities in isolated ventricular myocytes. We have previously shown that carbamylated PAF-induced repolarization abnormalities result from the protein kinase C (PKC) ε-dependent phosphorylation of the two-pore domain potassium channel TASK-1. We now demonstrate that canine peri-op AF is associated with the phosphorylation-dependent loss of TASK-1 current. Further studies identified threonine 383 in the C terminus of human and canine TASK-1 as the phosphorylation site required for PAF-dependent inhibition of the channel. Using a novel phosphorylation site-specific antibody targeting the phosphorylated channel, we have determined that peri-op AF is associated with the loss of TASK-1 current and increased phosphorylation of TASK-1 at this site. |
13,515 | Ventricular activity morphological characterization: ectopic beats removal in long term atrial fibrillation recordings. | Ectopic beats are early heart beats remarkably different to the normal beat morphology that provoke serious disturbances in electrocardiographic analysis. These beats are very common in atrial fibrillation (AF), causing important residua when ventricular activity has to be removed for atrial activity (AA) analysis. In this work, a method is proposed to cancel out ectopics by discriminating between normal and abnormal beats, with an accuracy higher than 99%, through QRS morphological delineation and characterization. The most similar ectopics to the one under cancellation are clustered to provide a very precise cancellation template. Simulated and real AF recordings were used to validate the method. A new index, able to estimate the presence of ventricular residue after ectopics cancellation, was defined. Results by using the 2, 4, 6, …, 30 most similar ectopics to the one under study yielded optimal cancellation for templates composed of 10 beats. Furthermore, these beats were very likely located close to the ectopic under cancellation, which could facilitate the algorithm implementation. As conclusion, the proposed method is an effective way to remove ectopics from long term AF recordings and get them ready for the application of any QRST cancellation technique able to extract the AA in optimal conditions. Moreover, it could also detect, characterize and remove ectopics in any other type of non-AF recordings. |
13,516 | Radial basis function neural networks applied to efficient QRST cancellation in atrial fibrillation. | The most extended noninvasive technique for medical diagnosis and analysis of atrial fibrillation (AF) relies on the surface elctrocardiogram (ECG). In order to take optimal profit of the ECG in the study of AF, it is mandatory to separate the atrial activity (AA) from other cardioelectric signals. Traditionally, template matching and subtraction (TMS) has been the most widely used technique for single-lead ECGs, whereas multi-lead ECGs have been addressed through statistical signal processing techniques, like independent component analysis. In this contribution, a new QRST cancellation method based on a radial basis function (RBF) neural network is proposed. The system is able to provide efficient QRST cancellation and can be applied both to single and multi-lead ECG recordings. The learning algorithm used for training the RBF makes use of a special class of network, known as cosine RBF, by updating selected adjustable parameters to minimize the class-conditional variances at the outputs of the network. The experiments verify that RBFs trained by the proposed learning algorithm are capable of reducing the QRST complex dramatically, a property that is not shared by other methods and conventional feed-forward neural networks. Average Results (mean ± std) for the RBF method in cross-correlation (CC) between original and estimated AA are CC=0.95±0.038 being the mean square error (MSE) for the same signals, MSE=0.311±0.078. Regarding spectral parameters, the dominant amplitude (DA) and the mean power spectral (MP) were DA=1.15±0.18 and MP=0.31±0.07, respectively. In contrast, traditional TMS-based methods yielded, for the best case, CC=0.864±0.041, MSE=0.577±0.097, DA=0.84±0.25 and MP=0.24±0.07. The results prove that the RBF based method is able to obtain a remarkable reduction of ventricular activity and a very accurate preservation of the AA, thus providing high quality dissociation between atrial and ventricular activities in AF recordings. |
13,517 | Early repolarization with horizontal ST segment may be associated with aborted sudden cardiac arrest: a retrospective case control study. | Risk stratification of the early repolarization pattern (ERP) is needed to identify malignant early repolarization. J-point elevation with a horizontal ST segment was recently suggested as a malignant feature of the ERP. In this study, the prevalence of the ERP with a horizontal ST segment was examined among survivors of sudden cardiac arrest (SCA) without structural heart disease to evaluate the value of ST-segment morphology in risk stratification of the ERP.</AbstractText>We reviewed the data of 83 survivors of SCA who were admitted from August 2005 to August 2010. Among them, 25 subjects without structural heart disease were included. The control group comprised 60 healthy subjects who visited our health promotion center; all control subjects were matched for age, sex, and underlying disease (diabetes mellitus, hypertension). Early repolarization was defined as an elevation of the J point of at least 0.1 mV above the baseline in at least two continuous inferior or lateral leads that manifested as QRS slurring or notching. An ST-segment pattern of <0.1 mV within 100 ms after the J point was defined as a horizontal ST segment.</AbstractText>The SCA group included 17 men (64%) with a mean age of 49.7 ± 14.5 years. The corrected QTc was not significantly different between the SCA and control groups (432.7 ± 37.96 vs. 420.4 ± 26.3, respectively; p = 0.089). The prevalence of ERP was not statistically different between the SCA and control groups (5/25, 20% vs. 4/60, 6.7%, respectively; p = 0.116). The prevalence of early repolarization with a horizontal ST segment was more frequent in the SCA than in the control group (20% vs. 3.3%, respectively; p = 0.021). Four SCA subjects (16%) and one control subject (1.7%) had a J-point elevation of >2 mm (p = 0.025). Four SCA subjects (16%) and one (1.7%) control subject had an ERP in the inferior lead (p = 0.025).</AbstractText>The prevalence of ERP with a horizontal ST segment was higher in patients with aborted SCA than in matched controls. This result suggests that ST morphology has value in the recognition of malignant early repolarization.</AbstractText> |
13,518 | The changing pattern of endomyocardial fibrosis in South-west Nigeria. | Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy, the prevalence of which is declining globally. This study was carried out to determine if there were changing patterns in its local prevalence in South-West Nigeria.</AbstractText>We reviewed the medical records of all patients admitted to or attending the cardiology clinic or medical outpatient/specialty clinics in the Department of Medicine, Ladoke Akintola University of Technology Teaching Hospital, Osogbo, South-West Nigeria. Medical data for those with EMF from January 2003 to December 2009 were retrieved and analyzed.</AbstractText>Only three cases of EMF were identified from a total of 12,794 medical patients containing a subset of 7956 cardiac patients. The prevalence of EMF was 0.02% and 0.04% for medical and cardiac patients, respectively. All the patients with EMF were in the second or third decades of life, and had right ventricular EMF and atrial fibrillation, but no eosinophilia.</AbstractText>This study shows that the prevalence of EMF has declined in the study area from 10% in the 1960s and 1970s to 0.02% for medical cases and 0.04% for cardiac cases in the first decade of the 21st century. Right ventricular EMF still predominates, but without eosinophilia. Improved health care delivery's positive impact on the control of communicable diseases might be responsible for these observed changes. More work needs to be done both within and outside Nigeria to follow this trend and unravel the mystery surrounding this poorly understood cardiac disease.</AbstractText> |
13,519 | Insights from cardiac development relevant to congenital defects and adult clinical anatomy. | Advances made in understanding temporal changes in structure of the developing heart, along with advances in knowledge of the lineage of cardiomyocytes forming the components of cardiac chambers, permit us to draw inferences concerning substrates for arrhythmias such as atrial fibrillation and outflow tract tachycardias. We frame these insights in our description of the formation of cardiac chambers. Adult-like electrocardiograms can be generated by developing hearts before it is possible to recognize an anatomically discrete conduction system. Working components of the atrial and ventricular chambers, which are rapidly conducting, balloon from walls of the primary heart tube, themselves slowly conducting. Recognition of the locations of these populations of primary and secondary myocardial pools suggests that some potential myocardial substrates (those producing outflow tract tachycardias) initially had a primary phenotype. In contrast, cardiomyocytes forming pulmonary venous sleeves, substrates for many cases of atrial fibrillation, have never possessed a primary phenotype. This article is part of a JCTR special issue on Cardiac Anatomy. |
13,520 | Shock or no shock - a question of philosophy or should intraoperative implantable cardioverter defibrillator testing be recommended? | Implantation of implantable cardioverter defibrillators (ICDs) in patients with a high risk for life-threatening ventricular arrhythmias is a standard therapy. The development of new ICD leads, shock algorithms, high-energy defibrillators and rapid energy supply has improved the devices. Nevertheless, the discussion regarding 'shock or no shock' to test the system intraoperatively has not silenced yet.</AbstractText>In this study, all 718 patients (60.0 ± 14.2 years old, 570 male) who were treated with a first ICD at our institution since 2005 were analysed. The indication for implantation was primarily prophylactic in 511 patients (71.3%). Underlying diseases included ischaemic cardiomyopathy (358 patients, 50%), dilated cardiomyopathy (270 patients, 37.7%) and others (12.3%). Mean ejection fraction was 27.4 ± 11.8%. Intraoperative ventricular fibrillation was induced with a T-wave shock or burst stimulation. The primary end-point was failing the initial intraoperative testing.</AbstractText>During the initial testing, 28 patients (3.9%) had a defibrillation threshold (DFT) >21 J. The mean age of these patients was 51 ± 14 years, ranging from 22 to 71 years, 20 were male, and the ejection fraction was 23.8 ± 11.8%. The indication for ICD implantation was prophylactic in 13 patients. Twenty-one of the 28 patients suffered from dilated cardiomyopathy, whereas seven patients had ischaemic cardiomyopathy. Twenty-four ICDs were implanted on the left side and four on the right side. None of the patients had been treated with amiodarone at the time of implantation. All patients achieved a sufficient DFT ≤ 21 J by changing the ICD leads, device repositioning and/or optimizing the shock configuration.</AbstractText>The standard of care intraoperative ICD testing remains necessary.</AbstractText> |
13,521 | Effect of bucindolol on heart failure outcomes and heart rate response in patients with reduced ejection fraction heart failure and atrial fibrillation. | There is little evidence of beta-blocker treatment benefit in patients with heart failure and reduced left ventricular ejection fraction (HFREF) and atrial fibrillation (AF). We investigated the effects of bucindolol in HFREF patients with AF enrolled in the Beta-blocker Evaluation of Survival Trial (BEST).</AbstractText>A post-hoc analysis of patients in BEST with and without AF was performed to estimate the effect of bucindolol on mortality and hospitalization. Patients were also evaluated for treatment effects on heart rate and the influence of beta1-adrenergic receptor position 389 (β(1)389) arginine (Arg) vs. glycine (Gly) genotypes. In the 303/2708 patients in AF, patients receiving bucindolol were more likely to achieve a resting heart rate ≤ 80 b.p.m. at 3 months (P < 0.005) in the absence of treatment-limiting bradycardia. In AF patients and sinus rhythm (SR) patients who achieved a resting heart rate ≤ 80 b.p.m., there were beneficial treatment effects on cardiovascular mortality/cardiovascular hospitalization [hazard ratio (HR) 0.61, P = 0.025, and 0.79, P = 0.002]. Without achieving a resting heart rate ≤ 80 b.p.m., there were no treatment effects on events in either group. β(1)389-Arg/Arg AF patients had nominally significant reductions in all-cause mortality/HF hospitalization and cardiovascular mortality/hospitalization with bucindolol (HR 0.23, P = 0.037 and 0.28, P = 0.039), whereas Gly carriers did not. There was no evidence of diminished heart rate response in β(1)389-Arg homozygotes.</AbstractText>In HFREF patients with AF, bucindolol was associated with reductions in composite HF endpoints in those who achieved a resting heart rate ≤ 80 b.p.m. and nominally in those with the β(1)389-Arg homozygous genotype.</AbstractText> |
13,522 | Dissimilar ventricular rhythms: implications for ICD therapy. | Sensing of left ventricular (LV) activity in some devices used for cardiac resynchronization therapy (CRT) was designed primarily to prevent the delivery of an LV stimulus into the LV vulnerable period. Such a sensing function of the LV channel is not universally available in contemporary CRT devices. Recordings of LV electrograms may provide special diagnostic data unavailable solely from the standard right ventricular electrogram and corresponding marker channel. We used the LV sensing function of Biotronik CRT defibrillators to find 3 cases of dissimilar ventricular rhythms or tachyarrhythmias. Such arrhythmias are potentially important because concomitant slower right ventricular activity may prevent or delay implantable cardioverter-defibrillator therapy for a life-threatening situation involving a faster and more serious LV tachyarrhythmia. Dissimilar ventricular rhythms may not be rare and may account for cases of unexplained sudden death with a normally functioning implantable cardioverter-defibrillator and no recorded terminal arrhythmia. |
13,523 | Antipsychotic drugs are associated with pulseless electrical activity: the Oregon Sudden Unexpected Death Study. | There has been a paradigm shift in the manifestation of sudden cardiac arrest (SCA), with steadily decreasing rates of ventricular fibrillation/tachycardia (VF/VT) and a significant increase in the proportion of pulseless electrical activity (PEA) and asystole.</AbstractText>Since PEA is marked by failure of myocardial contractility, we evaluated the potential role of drugs that affect cardiac contractility in the pathophysiology of human PEA.</AbstractText>Subjects with out-of-hospital SCA (aged≥18 years) who underwent attempted resuscitation were evaluated in the ongoing Oregon Sudden Unexpected Death Study (2002-2009). Specific classes of medications with either negative or positive cardiac inotropic effects were evaluated for association with occurrence of PEA vs VF/VT by using Pearson χ(2) tests and logistic regression.</AbstractText>PEA cases (n = 309) were older than VF/VT cases (n = 509; 68±14 years vs 64±15 years; P<.0001) and were more likely to be women (39% vs 25%; P<.0001). In a logistic regression model adjusting for age, sex, comorbidities, disease burden, and resuscitation variables, antipsychotic drugs (odds ratio 2.40; 95% confidence interval 1.26-4.53) were significant predictors of PEA vs VF/VT. Conversely, use of digoxin was associated with the occurrence of VF/VT (P<.0001).</AbstractText>When drugs modifying myocardial contractility were evaluated in a comprehensive analysis of patients who suffered SCA, use of antipsychotic agents was a significant and independent predictor of manifestation with PEA.</AbstractText>Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,524 | Mechanisms of ranolazine's dual protection against atrial and ventricular fibrillation. | Coronary artery disease and heart failure carry concurrent risk for atrial fibrillation and life-threatening ventricular arrhythmias. We review evidence indicating that at therapeutic concentrations, ranolazine has potential for dual suppression of these arrhythmias. Mechanisms and clinical implications are discussed. |
13,525 | Change of B-type natriuretic peptide after surgery and its association with rhythm status in patients with chronic severe mitral regurgitation. | B-type natriuretic peptide (BNP) is a useful biomarker of cardiac function in patients with mitral regurgitation (MR). However, the change in BNP in association with rhythm status after corrective surgery has not been studied.</AbstractText>A total of 101 patients with chronic severe MR undergoing surgery were prospectively enrolled. BNP assays and echocardiographic studies were conducted before and 6 months after surgery. Patients were divided into 3 groups according to pre- and postoperative rhythm (sinus to sinus [SS], n = 61; atrial fibrillation [AF] to sinus [AS], n = 28; AF to AF [AA], n = 12).</AbstractText>BNP decreased only in the AS group 6 months after mitral surgery (from 218.0 ± 136.5 to 94.7 ± 85.1 pg/mL; P < 0.001) but not in the SS or AA groups (P for interaction = 0.001). However, changes of echocardiographic parameters after surgery were not different among the 3 groups. In the AA group, postoperative left ventricular (LV) end-diastolic dimension and left atrial volume were higher than the other groups. Significant determinants of BNP were the presence of AF and the higher pulmonary artery systolic pressure preoperatively (β = 0.767 and P = 0.001 for AF; β = 0.022 and P = 0.019 for pulmonary artery systolic pressure), and the lower LV ejection fraction postoperatively (β = -0.030; P = 0.011).</AbstractText>After surgical correction of chronic organic severe MR, BNP decreased only in patients with preoperative AF which was converted to sinus rhythm postoperatively. A reduction in BNP was not observed when rhythm status did not change. BNP activation was associated with the presence of AF and LV systolic dysfunction, suggesting its prognostic value.</AbstractText>Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,526 | [Arrhythmogenic right ventricular cardiomyopathy as a cause of sudden death in young people--literature review]. | Arrhythmogenic right ventricular cardiomyopathy/dysplasia is a progressive condition with right ventricular myocardium being replaced by fibro-fatty tissue. It is a hereditary disorder mostly caused by desmosome gene mutations. The prevalence of arrhythmogenic right ventricular cardiomyopathy is about 1/1000-5000. Clinical presentation is usually related to ventricular tachycardias, syncope or presyncopa, or ventricular fibrillation leading to cardiac arrest, mostly in young people and athletes. It may be difficult to make the diagnosis of arrhythmogenic right ventricular cardiomyopathy due to several problems arising from the specificity of electrocardiograph abnormalities, different potential etiologies of ventricular arrhythmias with a left bundle branch morphology, the assessment of the right ventricular structure and function, and the interpretation of endomyocardial biopsy findings. Therefore, standardized diagnostic criteria have been proposed by the Study Group on arrhythmogenic right ventricular cardiomyopathy of the European Society of Cardiology. In order to make the diagnosis ofarrhythmogenic right ventricular cardiomyopathy, a number of clinical tests are employed, including the electrocardiogram, echocardiography, myocardial perfusion scintigraphy, myocardial biopsy, right ventricular angiography, cardiac magnetic resonance imaging and genetic testing. The therapeutic options include beta blockers, antiarrhythmic drugs, catheter ablation, and implantable cardioverter defibrillator. The implantable cardioverter defibrillator is the most effective safe-guard against arrhythmic sudden death. Preparticipation screening for sport eligibility has been proven to be effective in detecting asymptomatic patients and sport disqualification has been lifesaving, substantially declining sudden death in young athletes. |
13,527 | Restored left ventricular function following transcatheter closure of a persistent ductus arteriosus in an adult. | Recently, transcatheter device occlusion has become the first choice treatment for adult persistent ductus arteriosus (PDA). However, various complications such as atrial fibrillation requiring anticoagulation, pulmonary hypertension, and ventricular dysfunction may challenge the interventionist. We report a 61-year-old patient with a large PDA complicated by left ventricular dysfunction, atrial fibrillation, and left atrial thrombus. Computed tomography documented the PDA of Krichenko type A with the narrowest diameter of 8 mm. We successfully closed the PDA using an Amplatzer duct occluder under anticoagulation with wafarin. His post-operative course was complicated by ventricular tachycardia and deteriorating left ventricular pump function. Although endomyocardial biopsy from the left ventricle showed myocardial hypertrophy and interstitial fibrosis, possibly caused by chronic volume overload, left ventricular pump function improved dramatically with restoration of sinus rhythm during follow-up. Left ventricular dysfunction, even when associated with histological changes, may be nearly normalized by volume unloading in an adult with a large PDA. <<b>Learning objective:</b> Transcatheter device occlusion has become the first choice for adult persistent ductus arteriosus (PDA). It is important to note various complications associated with transcatheter occlusion of PDA in adult, such as arrhythmia, pulmonary hypertension, and ventricular dysfunction. Temporally dysfunction of left ventricular (LV) systolic performance usually occurs following PDA closure, because of reduced muscle fiber stretch by the sudden reduction in LV volume overload and increased LV afterload. Although histological remodeling of LV may be caused by volume overload due to significant left-to-right shunt in adults, volume unloading can, not only prevent further deterioration of LV function, but also may also reverse the substrate of arrhythmia.>. |
13,528 | [Ultrasound in the electrophysiological cardiac catheterization laboratory]. | During recent years the need for intraprocedural imaging has increased. Fluoroscopy and angiography are frequently supplemented by pre-procedural magnetic resonance or computed tomography imaging as well as electroanatomic mapping techniques. However, poor real-time imaging quality of soft tissue, radiation exposure, and contrast media consumption are disadvantageous. Ultrasound techniques are characterized by high-quality imaging of soft tissue that can be obtained in real time. All relevant anatomical structures and their relationships to catheters can be evaluated at any time during the procedure. Moreover, functional analysis, e.g., flow measurements and monitoring for complications, is possible. Transesophageal and especially intracardiac echocardiography (ICE) contribute enormously to effectiveness and safety of complex procedures. ICE has been shown to be useful in transseptal procedures like atrial fibrillation ablation but also in ablation procedures for ventricular tachycardias. |
13,529 | Effect of age on treatment, trends and outcome of patients hospitalized with atrial fibrillation: insights from a 20-years registry in a Middle-Eastern country (1991-2010). | Most studies on atrial fibrillation (AF) epidemiology, treatment, and outcomes have included mainly Caucasians patients. The world literature on AF in other ethnicities is very limited particularly in the elderly.</AbstractText>The aim of this study was to compare the clinical characteristics, treatment and outcome of elderly and younger patients hospitalized with AF in a Middle-Eastern country and examine the trends of AF etiologies over a 20-year period.</AbstractText>A retrospective analysis of a prospective registry of all patients hospitalized with AF in Qatar from 1991 through 2010 was made. Patients were divided into three groups; group 1: patients ≤50 years old, group 2: patients between 51 and 70 years old, and group 3: patients >70 years old. Clinical characteristics, management, and outcomes of AF patients were compared according to age.</AbstractText>Between the year 1991 and the end of 2010, a total 3848 consecutive patients were admitted with AF. One thousand three hundred and forty-five patients were ≤50 years, 1759 were between 51 and 70 years and 744 patients were >70 years old. Elderly patients were more likely to have hypertension and chronic renal impairment. There was a higher prevalence of associated coronary artery disease and aortic stenosis in elderly patients with a lower left ventricular ejection fraction than the younger age groups. A lower use of anticoagulation in the elderly group was observed but there was no underuse of other evidence-based medications. The older AF patients had significantly higher in-hospital mortality and stroke rates with no significant changes in mortality trends over the 20 years of study. An increasing trend of the associated acute coronary syndromes, hypertension and diabetes mellitus prevalence was observed in the elderly group.</AbstractText>Anticoagulation remains underutilized in elderly patients with AF despite proven efficacy and increasing trends of cardiovascular comorbidities. The current study underscores the urgent need for prospective studies to investigate warfarin contraindications, relative warfarin efficacy and bleeding risks in our region to help guide healthcare providers in warfarin prescribing in this frail patient population and consequently reduce the risk of AF-related disabling strokes and mortality.</AbstractText> |
13,530 | Cause of very late recurrence of atrial fibrillation or flutter after catheter ablation for atrial fibrillation. | The major mechanism underlying the early recurrence of atrial fibrillation (AF) after ablation is mainly reconnection of the isolated pulmonary vein (PV); however, the mechanism responsible for very late recurrence (VLR) has not been fully elucidated. The purpose of the present study was to investigate the mechanism underlying VLR. The study population included 150 consecutive patients with AF who underwent a second session of catheter ablation because of recurrence. We divided them into 2 groups according to the point of initial AF recurrence: the late recurrence group (LR group, initial recurrence 3 to 12 months after ablation, n = 124) and the VLR group (initial recurrence >12 months after ablation, n = 26). We identified PVs with ectopic foci (trigger PVs) in the first procedure and checked their electrical reconnection in the second procedure. The prevalence of PV reconnection and trigger PV reconnection were significantly lower in the VLR group than in LR group (LR vs VLR, 90% vs 69% and 48% vs 27%, p = 0.007 and p = 0.045, respectively). In the VLR group, left ventricular systolic and diastolic function were significantly worse than in the LR group, and more patients in the VLR group required non-PV trigger ablation in the second session than did those in the LR group (30% vs 54%, p = 0.034). In conclusion, electrical PV reconnection contributed less to VLR than to LR. Progression of the AF substrate might be an important mechanism responsible for VLR. |
13,531 | Telemedicine and cardiac implants: what is the benefit? | Cardiac implantable electronic devices are increasing in prevalence. The post-implant follow-up is important for monitoring both device function and patient condition. However, practice is inconsistent. For example, ICD follow-up schedules vary from 3 monthly to yearly according to facility and physician preference and availability of resources. Recommended follow-up schedules impose significant burden. Importantly, no surveillance occurs between follow-up visits. In contrast, implantable devices with automatic remote monitoring capability provide a means for performing constant surveillance, with the ability to identify salient problems rapidly. Remote home monitoring reduces the volume of device clinic visits and provides early detection of patient and/or system problems. |
13,532 | Role of defibrillation threshold testing in the contemporary defibrillator patient population. | Defibrillation threshold (DFT) testing has been performed to prove functionality of the implantable cardioverter defibrillator (ICD). Over the past years it has become increasingly controversial because of possible morbidity and mortality. The goal of this study was to determine unsuccessful shock testing and report strategies used to overcome these problems.</AbstractText>A total of 314 patients with a de novo implantation of an ICD and 127 patients receiving a generator exchange were identified retrospectively. All patients underwent defibrillation threshold testing after induction of VF using a low-energy T-wave shock during the intervention, 2 shock tests after de novo implantations, 1 after generator change. A safety margin of 10 J or more was requested. Seven (2.3%) patients in the de novo group and 2 patients (1.4%) in the generator exchange group could not be defibrillated using the standard approach. All of those patients had either chronic amiodarone therapy, secondary prevention or a cardiac resynchronization therapy device (CRT). In univariate analysis, amiodarone therapy, dilated cardiomyopathy, and lower ejection fraction were predictors of failure.</AbstractText>Our study's results as well as a review of the current literature favor shock testing, especially in patients with specific risk factors as mentioned above.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,533 | Comparison of fixed tilt and tuned defibrillation waveforms: the PROMISE study. | All modern defibrillation systems use biphasic shock waveforms. Typically a fixed tilt waveform is used for implantable defibrillators (ICDs), but a tuned waveform with duration based on shock impedance may be superior based on theoretical calculations.</AbstractText>The objective of this study was to compare defibrillation efficacy of fixed tilt and tuned waveforms.</AbstractText>PROMISE was designed as a prospective, within-patient, randomized study of defibrillation thresholds (DFTs) comparing a tuned (assuming a 3.5 milliseconds membrane time constant) versus a 50/50% tilt waveform. All patients had a left pectoral implant (active can) and testing was performed with a single coil shocking configuration ("SVC coil OFF"). DFTs were measured in random order with a binary search method in 52 patients, using the high-voltage lead impedance to select the pulse widths for both waveforms.</AbstractText>At the DFT, the tuned waveform had similar delivered energy (10.5 ± 6.3 vs 9.5 ± 5.5 J, P = 0.47), stored energy (13.6 ± 7.9 vs 11.3 ± 6.3 J, P = 0.06), peak current (7.5 ± 3.0 vs 6.8 ± 2.2 A, P = 0.09), and delivered voltage (451.0 ± 134.5 vs 411.5 ± 120.7 V, P = 0.05) compared with the 50/50% tilt waveform.</AbstractText>The DFTs for 3.5-millisecond time constant based tuned and 50/50% tilt waveforms are similar using a single coil, left pectoral active can.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,534 | Kounis-Zavras syndrome presenting with ventricular arrhythmias and cardiogenic shock. | In this case report we describe a case of the Kounis-Zavras syndrome (coincidental occurrence of chest pain and allergic reactions accompanied by clinical and laboratory findings of cardiac ischemia). A 34-year-old woman presented to the emergency unit with severe chest pain from 2 h. She reported a medical history of asthma. On arrival, her heart rate was 125 beats/min and her systolic blood pressure (SBP) was 70 mmHg. A repeated electrocardiogram displayed dynamic changes with ST-segment elevation in D1-aVL leads and ST-segment depression in infero-posterior leads. Two episodes of ventricular fibrillation were observed. The coronary artery angiography showed multivessel coronary vasospasms. Intracoronary nitroglycerin was used to alleviate the coronary vasospasms. Contemporaneously, the patient's husband came to the hospital reporting a history of ketorolac consumption some hours before the onset of the acute event for headache symptoms. This crucial information permitted us to suppose it was a case of allergic myocardial infarction during anaphylactic shock due to ketorolac. Betametasone, chlorphenamine, and ranitidine were administered and progressively a full recovery of SBP and of clinical status was observed. <<b>Learning objective:</b> Allergic myocardial infarction (Kounis-Zavras syndrome) is a complex acute coronary syndrome which requires rapid treatment decisions. Most of the information on this syndrome comes from case reports or small case series. It should be considered in young, healthy patients when they develop acute coronary syndrome after administration of potentially allergic agent. The treatment should both dilate coronary vessels and suppress the allergic reaction (steroids, antihistamines, fluid resuscitation, oxygen, nitrates, calcium channel blockers).>. |
13,535 | New insights into the beneficial electrophysiologic profile of ranolazine in heart failure: prevention of ventricular fibrillation with increased postrepolarization refractoriness and without drug-induced proarrhythmia. | Ranolazine inhibits late Na(+) and K(+) currents. Earlier studies have reported an antiarrhythmic effect. The aim of the present study was to understand whether ranolazine could still preserve its antiarrhythmic properties in the settings of chronic heart failure (CHF).</AbstractText>In 12 female rabbits, CHF was induced by 4 weeks of rapid ventricular pacing leading to a decrease in ejection fraction. Twelve rabbits underwent sham operation. Isolated hearts were Langendorff perfused and demonstrated a significant QT prolongation after induction of heart failure. Ranolazine caused a concentration-dependent (10 and 30 μmol/L) increase of action potential duration (APD(90)) in sham-operated and failing hearts. Eight endo- and epicardial monophasic action potentials revealed a nonsignificant increase in spatial and temporal dispersion of repolarization. The increase in APD(90) was accompanied by a greater increase in refractory period, resulting in a significant increase in postrepolarization refractoriness in sham-operated (+29 ms and +55 ms; P < .01) and failing (+22 ms and +30 ms; P < .05) hearts. In control conditions, programmed ventricular stimulation and a burst pacing protocol led to ventricular fibrillation (VF) in 5 of the 12 sham-operated (6 episodes) and in 7 of the 12 failing (18 episodes) hearts. In the presence of ranolazine, VF was inducible in only 2 of 12 failing hearts (5 episodes). In the presence of low [K(+)], only 1 ranolazine-treated sham-operated heart developed early afterdepolarizations and ventricular tachyarrhythmias despite significant QT prolongation.</AbstractText>Ranolazine decreases inducibility of VF in the presence of a significant increase in postrepolarization refractoriness. This antiarrhythmic effect in the intact heart is preserved in CHF and is not associated with drug-induced proarrhythmia.</AbstractText>Copyright © 2012 Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,536 | Successful coronary angiography with adequate image acquisition using a combination of gadolinium and a power injector in a patient with severe iodine contrast allergy. | A history of severe allergic reaction to iodine contrast leading to anaphylactic shock presents a dilemma in patients requiring cardiac catheterization. As an alternative, gadolinium has been an interesting and potentially useful agent. However, gadolinium produces poor image quality and has been associated with significant arrhythmias in small case series. Furthermore, there is no consensus about the maximal allowable dose that can be administered to a patient. In the present report, a successful combination of gadolinium contrast with a power injector that produced adequate image quality in a patient with severe allergy to iodine contrast is described. The case was complicated by the occurrence of ventricular fibrillation when damping occurred during injection of contrast into the right coronary artery. This complication has been reported previously with intracoronary gadolinium injection. The report is followed by a brief literature review. |
13,537 | Assessment of genetic causes of cardiac arrest. | Unexplained cardiac arrest is defined as a cardiac arrest in the absence of coronary artery disease and overt structural heart disease, present in 5%-10% of cardiac arrest survivors. A genetic contribution to cardiac arrest is more common in this population, most commonly attributed to an inherited ion channel abnormality leading to familial syncope and sudden death. The common causes are Long QT and Brugada syndrome, catecholaminergic ventricular tachycardia, idiopathic ventricular fibrillation, and early repolarization syndrome. Latent structural causes include inherited cardiomyopathy such as arrhythmogenic right ventricular cardiomyopathy. We review these causes in detail and a structured approach to the investigation of these patients, which provides a diagnosis in approximately half of these patients. This allows for the initiation of disease-specific treatments and enables family screening. |
13,538 | Detection of subclinical atrial dysfunction by two-dimensional echocardiography in patients with overt hyperthyroidism. | Hyperthyroidism is an important cardiovascular risk factor in the development of atrial fibrillation and heart failure. Increased atrial electromechanical intervals are used to predict atrial fibrillation, measured by tissue Doppler imaging (TDI).</AbstractText>To evaluate atrial electromechanical delay (EMD) and left atrial (LA) mechanical function in patients with overt hyperthyroidism.</AbstractText>Thirty-four patients with overt hyperthyroidism and 34 controls were included. A diagnosis of overt hyperthyroidism was reached with decreased serum thyroid-stimulating hormone (TSH) and increased free T4 (fT4) concentrations. Using TDI, atrial electromechanical coupling (PA) was obtained from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septum) and right ventricular tricuspid annulus (PA tricuspid). LA volumes (maximum, minimum and presystolic) were measured by the disks method in apical four-chamber view and indexed to body surface area. LA active and passive emptying volumes and fractions were calculated.</AbstractText>LA diameter was significantly higher in hyperthyroid patients (P=0.001). LA passive emptying volume and fraction were significantly decreased in hyperthyroid patients (P=0.038 and P<0.001). LA active emptying volume and fraction were significantly increased in hyperthyroid patients (P<0.001 and P<0.001). Left and right intra-atrial (PA lateral-PA septum and PA septum-PA tricuspid) and interatrial (PA lateral-PA tricuspid) EMDs were significantly higher in hyperthyroid patients (29.2 ± 4.4 vs 18.1 ± 2.6, P<0.001; 18.7 ± 4.3 vs 10.6 ± 2.0, P<0.001; and 10.5 ± 2.9 vs 7.1 ± 1.2, P<0.001, respectively). Stepwise linear regression analysis demonstrated that fT4 and TSH concentrations were independent predictors of interatrial EMD (β=0.436, P<0.001 and β=-0.310, P=0.005, respectively).</AbstractText>This study showed prolonged atrial electromechanical intervals and impaired LA mechanical function in patients with overt hyperthyroidism, which may be an early sign of subclinical cardiac involvement and dysrhythmias in overt hyperthyroidism.</AbstractText>Copyright © 2012 Elsevier Masson SAS. All rights reserved.</CopyrightInformation> |
13,539 | Alternative approach to improving survival of patients with out-of-hospital primary cardiac arrest. | Out-of-hospital cardiac arrest (OHCA) is a common cause of death. In spite of recurring updates of guidelines, the survival of patients with OHCA was essentially unchanged from the mid 1970s to the mid 2000s, averaging 7.6% for all OHCA and 17.7% for OHCA due to ventricular fibrillation. In the past, changes in one's approach to resuscitation had to await the semi-decennial publications of guidelines. Following approved guidelines (at times based on consensus), survival rates of patients with OHCA were extremely variable, with only a few areas having good results. An alternative approach to improving survival is to use continuous quality improvement (CQI), a process often used to address public health problems. Continuous quality improvement advocates that one obtain baseline data and, if not optimal, make changes and continuously re-evaluate the results. Using CQI, we instituted cardiocerebral resuscitation as an alternative approach and found significant improvement in survival of patients with OHCA. The changes we made to the therapy of patients with primary OHCA, called cardiocerebral resuscitation, were based primarily on extensive experimental laboratory data. Using cardiocerebral resuscitation as a model for CQI, neurologically intact survival of patients with OHCA in ventricular fibrillation improved in 2 rural counties in Wisconsin, from 15% to 39%, and in 60 emergency medical systems in Arizona, to 38%. By advocating chest compression only CPR for bystanders of patients with primary OHCA and encouraging the use of cardiocerebral resuscitation by emergency medical systems, survival of patients with primary cardiac arrest in Arizona increased over a 5-year period from 17.7% to 33.7%. We recommend that all emergency medical systems determine their baseline survival rates of patients with OHCA and a shockable rhythm, and consider implementing the CQI approach if the community does not have a neurologically intact survival rate of at least 30%. |
13,540 | Midlife stroke risk and cognitive decline: a 10-year follow-up of the Whitehall II cohort study. | Stroke is associated with an increased risk of dementia. However, it is unclear whether risk of stroke in those free of stroke, particularly in nonelderly populations, leads to differential rates of cognitive decline. Our aim was to assess whether risk of stroke in mid life is associated with cognitive decline over 10 years of follow-up.</AbstractText>We studied 4153 men and 1657 women (mean age, 55.6 years at baseline) from the Whitehall II study, a longitudinal British cohort study. We used the Framingham Stroke Risk Profile (FSRP), which incorporates age, sex, systolic blood pressure, diabetes mellitus, smoking, prior cardiovascular disease, atrial fibrillation, left ventricular hypertrophy, and use of antihypertensive medication. Cognitive tests included reasoning, memory, verbal fluency, and vocabulary assessed three times over 10 years. Longitudinal associations between FSRP and its components were tested using mixed-effects models, and rates of cognitive change over 10 years were estimated.</AbstractText>Higher stroke risk was associated with faster decline in verbal fluency, vocabulary, and global cognition. For example, for global cognition there was a greater decline in the highest FSRP quartile (-0.25 of a standard deviation; 95% confidence interval: -0.28 to -0.21) compared with the lowest risk quartile (P = .03). No association was observed for memory and reasoning. Of the individual components of FSRP, only diabetes mellitus was associated independently with faster cognitive decline (β = -0.06; 95% confidence interval, -0.01 to 0.003; P = .03).</AbstractText>Elevated stroke risk at midlife is associated with accelerated cognitive decline over 10 years. Aggregation of risk factors may be especially important in this association.</AbstractText>Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,541 | [Research on automatic external defibrillator based on DSP]. | Electrical defibrillation is the most effective way to treat the ventricular tachycardia (VT) and ventricular fibrillation (VF). An automatic external defibrillator based on DSP is introduced in this paper. The whole design consists of the signal collection module, the microprocessor controlingl module, the display module, the defibrillation module and the automatic recognition algorithm for VF and non VF, etc. This automatic external defibrillator has achieved goals such as ECG signal real-time acquisition, ECG wave synchronous display, data delivering to U disk and automatic defibrillate when shockable rhythm appears, etc. |
13,542 | High E/e' disrupts the rapid lowering of blood glucose in response to exercise training. | No relationship between the ratio of peak early velocity of left ventricular inflow to peak systolic longitudinal velocity of the mitral annulus velocity (E/e') and insulin resistance has yet been shown in patients with cardiac disease. We hypothesized that patients with high E/e' values would tend not to show the rapid blood glucose-lowering in response to exercise training characteristic of impaired glucose tolerance (IGT) or diabetes mellitus (DM) patients.</AbstractText>The subjects were continuous IGT/DM patients (n = 27) participating in cardiac rehabilitation. All patients' E/e' values were measured by echocardiography. The patients' blood glucose levels (mg/dl) were measured just before (pre-BS) and after (post-BS) exercise training. Post-BS was subtracted from pre-BS to obtain ΔBS, and the relationship between E/e' and ΔBS was investigated.</AbstractText>E/e' correlated negatively with ΔBS. Moreover, E/e' was a significant predictor of ΔBS and as such was independent of hemoglobin A1c (HbA1c), pre-BS, and presence of atrial fibrillation on multivariate analysis.</AbstractText>Patients with high E/e', indicating high left ventricular filling pressure, were unlikely to exhibit the rapid glucose-lowering response.</AbstractText> |
13,543 | Anxiety and risk of ventricular arrhythmias or mortality in patients with an implantable cardioverter defibrillator. | A subgroup of patients with an implantable cardioverter defibrillator (ICD) experiences anxiety after device implantation. The purpose of the present study was to evaluate whether anxiety is predictive of ventricular arrhythmias and all-cause mortality 1 year post ICD implantation.</AbstractText>A total of 1012 patients completed the state version of the State-Trait Anxiety Inventory at baseline. The end points were ventricular arrhythmias and mortality the first year after ICD implantation.</AbstractText>Within the first year after ICD implantation, 19% of patients experienced a ventricular arrhythmia, and 4% died. Anxiety was associated with an increased risk of ventricular arrhythmias (hazard ratio [HR] = 1.017; 95% confidence interval [CI] = 1.005-1.028; p = .005) and mortality (HR = 1.038; 95% CI = 1.014-1.063; p = .002) in adjusted analysis. Patients with anxiety (highest tertile) had a 1.9 increased risk for ventricular arrhythmias (95% CI = 1.329-2.753; p =.001) and a 2.9 increased risk for mortality (95% CI = 1.269-6.677; p = .01) compared with patients with low anxiety (lowest tertile). Among 257 patients with cardiac resynchronization therapy, anxiety was associated with mortality (HR = 5.381; 95% CI = 1.254-23.092; p = .02) after adjusting for demographic and clinical covariates.</AbstractText>Anxiety was associated with an increased risk of ventricular arrhythmias and mortality 1 year after ICD implantation, independent of demographic and clinical covariates. Monitoring and treatment of anxiety may be warranted in a selected subgroup of high-risk patients with an ICD.</AbstractText> |
13,544 | Omega-3 fatty acids and cardiac arrhythmias. | There are suggestions of effects of marine omega-3 polyunsaturated fatty acids (PUFAs) in relation to ventricular arrhythmia and sudden cardiac death and, more recently, also of possible effects related to atrial fibrillation.</AbstractText>On the basis of the recently published human studies, this article not only focusses primarily on recent developments and current knowledge on the effect of marine omega-3 PUFAs on atrial fibrillation, but also provides a status for their effects on ventricular arrhythmias.</AbstractText>Marine omega-3 PUFAs may protect against ventricular arrhythmias, and there is growing evidence for an effect of marine omega-3 PUFAs in the prevention and treatment of atrial fibrillation. Further studies are needed to establish which patients are more likely to benefit from omega-3 PUFAs, the timing of treatment, and the dosages.</AbstractText> |
13,545 | The importance of increased percentage of biventricular pacing to improve clinical outcomes in patients receiving cardiac resynchronization therapy. | To describe the growing evidence that a maximal biventricular pacing is needed to gain the maximal benefits from cardiac resynchronization therapy (CRT).</AbstractText>Even small gains in the biventricular (BIV) pacing percentage are clinically important both to prevent acute heart failure and, more importantly, to improve survival.</AbstractText>Every effort should be made in all patients receiving CRT to approach 100% BIV pacing by a correct device programming, a correct pharmacologic regimen and atrioventricular nodal ablation in atrial fibrillation patients.</AbstractText> |
13,546 | Epinephrine for cardiac arrest. | Epinephrine is the primary drug administered during cardiopulmonary resuscitation (CPR) to reverse cardiac arrest. Epinephrine increases arterial blood pressure and coronary perfusion during CPR via alpha-1-adrenoceptor agonist effects. However, the dose, timing and indications for epinephrine use are based on limited animal data. Recent studies question whether epinephrine provides any overall benefit for patients.</AbstractText>A randomized controlled trial indicates that epinephrine for out-of-hospital cardiac arrest increases return of pulses, but does not significantly alter longer-term survival. Very large, well-controlled, observational studies suggest that, despite increases in return of pulses, epinephrine reduces long-term survival and functional recovery after CPR. Detrimental effects were greatest in patients found in ventricular fibrillation. Laboratory data suggest that harmful epinephrine-induced reductions in microvascular blood flow during and after CPR may offset the beneficial epinephrine-induced increase in arterial blood pressure during CPR.</AbstractText>The available clinical data confirm that epinephrine administration during CPR can increase short-term survival (return of pulses), but point towards either no benefit or even harm of this drug for more patient-centred outcomes (long-term survival or functional recovery). Prospective trials are needed to determine the correct dose, timing and patients for epinephrine in cardiac arrest.</AbstractText> |
13,547 | Left ventricular diastolic function is closely associated with mechanical function of the left atrium in patients with paroxysmal atrial fibrillation. | Left ventricular (LV) diastolic dysfunction may be a mechanism of left atrial (LA) electroanatomical remodeling in atrial fibrillation (AF). We evaluated the association between LV diastolic function and LA mechanical function in non-valvular paroxysmal AF (PAF).</AbstractText>In 286 patients with PAF (males 73%, 57 ± 11 years), LA size, indexed LA volume, LV diastolic function, and LA appendage flow velocity (LAA-FV) in sinus rhythm were measured using transthoracic echocardiography, transesophageal echocardiography and cardiac computed tomography. The LA voltage map was obtained using NavX contact mapping. Patients with impaired LA mechanical function (LAA-FV <58 cm/s, n=142) showed a higher E/Em ratio (10.3 vs. 9.2, P=0.034) and lower Em velocity (6.8 vs. 7.7 cm/s, P=0.004) than those with preserved function (LAA-FV ≥ 58 cm/s, n=144). The patient population displayed weak correlations of E/Em with LAA-FV (r=-0.19, P=0.003) and LA voltage (r=-0.23, P=0.004), but more significant association of E/Em and LAA-FV (r=-0.39, P<0.001) for age ≥ 55 years and LA diameter ≥ 40 mm. E/Em was an independent predictor of LAA mechanical function (β=-0.20, P=0.013) even after age, sex, LA size and comorbidities were controlled for.</AbstractText>In patients with non-valvular PAF, LA mechanical function is closely related to the degree of LA remodeling and LV diastolic function. Impaired LV diastolic function significantly contributes to LA electoanatomical remodeling in older patients with a larger LA.</AbstractText> |
13,548 | Pilot randomized trial of outpatient cardiac monitoring after cryptogenic stroke. | Observational studies indicate that outpatient cardiac monitoring detects previously undiagnosed atrial fibrillation (AF) in 5% to 20% of patients with recent stroke. However, it remains unknown whether the yield of monitoring exceeds that of routine clinical follow-up.</AbstractText>In a pilot trial, we randomly assigned 40 patients with cryptogenic ischemic stroke or high-risk transient ischemic attack to wear a Cardionet mobile cardiac outpatient telemetry monitor for 21 days or to receive routine follow-up alone. After thorough investigation, we excluded patients with documented AF or other apparent stroke pathogenesis. We contacted patients and their physicians at 3 months and at 1 year to ascertain any diagnoses of AF or recurrent stroke or transient ischemic attack.</AbstractText>The baseline characteristics of our cohort broadly matched those of previous observational studies of monitoring after stroke. In the monitoring group, patients wore monitors for 64% of the assigned days, and 25% of patients were not compliant at all with monitoring. No patient in either study arm received a diagnosis of AF. Cardiac monitoring revealed AF in zero patients (0%; 95% confidence interval, 0%-17%), brief episodes of atrial tachycardia in 2 patients (10%; 95% confidence interval, 1%-32%), and nonsustained ventricular tachycardia in 2 patients (10%; 95% confidence interval, 1%-32%).</AbstractText>In the first reported randomized trial of cardiac monitoring after cryptogenic stroke, the rate of AF detection was lower than expected, incidental arrhythmias were frequent, and compliance with monitoring was suboptimal. Our findings highlight the challenges of prospectively identifying stroke patients at risk for harboring paroxysmal AF and ensuring adequate compliance with cardiac monitoring. Clinical Trial Registration- URL: http://clinicaltrials.gov. Unique Identifier: NCT00715533.</AbstractText> |
13,549 | QTc prolongation prior to angiography predicts poor outcome and associates significantly with lower left ventricular ejection fractions and higher left ventricular end-diastolic pressures. | QT prolongation on the surface ECG is associated with sudden cardiac death. The cause of QT prolongation in ischaemic heart disease (IHD) patients remains unknown, but may be due to a complex interplay between genetic factors and impaired systolic and/or diastolic function through as yet unexplained mechanisms. It was hypothesised that QT prolongation before elective coronary angiography is associated with an increased mortality at six months.</AbstractText>Complete records of 321 patients who underwent coronary angiography were examined for QT interval corrected for heart rate (QTc), left ventricular ejection fraction (LVEF), left ventricular end-diastolic pressure (LVEDP) and known ischaemic heart disease risk factors. Patients were designated long QTc (LQTc) when they had prolonged QTc intervals or normal QTc (NQTc) when the QTc interval was normal. Patients with atrial fibrillation, bundle branch blocks, no ECG in the 24 hours before angiography, or a creatinine level > 200 µmol/l were excluded. Survival was determined telephonically at six months.</AbstractText>Twenty-eight per cent of the total population had LQTc. During follow up, 15 patients (4.7%) died suddenly, 73% of whom had a LQTc. LQTc was significantly associated with mortality (LQTc 12% vs NQTc 1.7%; p < 0.01), and with lower but normal LVEF (LQTc 52.9 ± 15.4% vs NQTc 61.6 ± 13.6%; p < 0.01), higher LVEDP at LVEF > 45% (LQTc 19.2 ± 9.0 mmHg vs NQTc 15.95 ± 7.5 mmHg; p < 0.05), hypercholesterolaemia and a negative family history of IHD.</AbstractText>In patients with sinus rhythm and normal QRS width, QTc prolongation before coronary angiography predicted increased mortality at six months. QTc also associated strongly with left ventricular systolic and diastolic dysfunction, hypercholesterolaemia and a negative family history of IHD.</AbstractText> |
13,550 | Diastolic dysfunction of aging is independent of myocardial structure but associated with plasma advanced glycation end-product levels. | Heart failure is associated with abnormalities of myocardial structure, and plasma levels of the advanced glycation end-product (AGE) N(ε)-(carboxymethyl)lysine (CML) correlate with the severity and prognosis of heart failure. Aging is associated with diastolic dysfunction and increased risk of heart failure, and we investigated the hypothesis that diastolic dysfunction of aging humans is associated with altered myocardial structure and plasma AGE levels.</AbstractText>We performed histological analysis of non-ischemic left ventricular myocardial biopsies and measured plasma levels of the AGEs CML and low molecular weight fluorophores (LMWFs) in 26 men undergoing coronary artery bypass graft surgery who had transthoracic echocardiography before surgery. None had previous cardiac surgery, myocardial infarction, atrial fibrillation, or heart failure.</AbstractText>The patients were aged 43-78 years and increasing age was associated with echocardiographic indices of diastolic dysfunction, with higher mitral Doppler flow velocity A wave (r = 0.50, P = 0.02), lower mitral E/A wave ratio (r = 0.64, P = 0.001), longer mitral valve deceleration time (r = 0.42, P = 0.03) and lower early diastolic peak velocity of the mitral septal annulus, e' (r = 0.55, P = 0.008). However, neither mitral E/A ratio nor mitral septal e' was correlated with myocardial total, interstitial or perivascular fibrosis (picrosirius red), immunostaining for collagens I and III, CML, and receptor for AGEs (RAGE), cardiomyocyte width, capillary length density, diffusion radius or arteriolar dimensions. Plasma AGE levels were not associated with age. However, plasma CML levels were associated with E/A ratio (r = 0.44, P = 0.04) and e' (r = 0.51, P = 0.02) and LMWF levels were associated with E/A ratio (r = 0.49, P = 0.02). Moreover, the mitral E/A ratio remained correlated with plasma LMWF levels in all patients (P = 0.04) and the mitral septal e' remained correlated with plasma CML levels in non-diabetic patients (P = 0.007) when age was a covariate.</AbstractText>Diastolic dysfunction of aging was independent of myocardial structure but was associated with plasma AGE levels.</AbstractText> |
13,551 | Comparison of the intrinsic vasorelaxant and inotropic effects of the antiarrhythmic agents vernakalant and flecainide in human isolated vascular and cardiac tissues. | This study explored the intrinsic vasorelaxant and inotropic effects of the mixed potassium and sodium channel blocker atrial antiarrhythmic vernakalant and the class IC antiarrhythmic agent flecainide in human isolated subcutaneous resistance artery and in ventricular trabecular muscle preparations. At test concentrations encompassing free plasma concentrations associated with clinical efficacy for conversion of atrial fibrillation, vernakalant (1-10 μM) displayed no significant direct effects on human resistance artery tone or ventricular contractility. In contrast, tested at equimolar concentrations, flecainide significantly reduced peak isometric contractile force (10 μM) and maximal rates of force development and decline (3 and 10 μM) in the human ventricular muscle preparation while displaying no significant effect on human resistance artery tone. The lack of effects of vernakalant on human resistance artery tone and ventricular muscle contractile function suggests that direct vasorelaxant and inotropic effects do not underlie the rare hypotensive events observed clinically with vernakalant, raising the possibility that secondary (eg, reflex) effects may mediate these events. The demonstration of negative inotropic effects with flecainide in the human ventricular muscle preparations in the absence of an effect on resistance artery tone suggests that the hemodynamic effects of flecainide observed clinically result primarily from direct negative inotropic effects. |
13,552 | The prevalence of early repolarization variant in Turkish male subjects: a clinical single center study. | Early repolarization variant (ERV) detected in surface ECG has traditionally been considered a benign finding, but the presence of this pattern has recently been associated with vulnerability to ventricular fibrillation in many case reports and case-control studies. There is no information regarding the prevalence of ERV within the Turkish population. The aim of this study was to evaluate the prevalence of ERV within a sample group of the healthy Turkish male population.</AbstractText>We assessed the prevalence of ERV within a community-based general population of 504 healthy male subjects (mean age 37.3±10.7 years; range 18 to 55 years) using 12-lead electrocardiography. ERV was stratified by two independent cardiologists according to the J-point elevation (≥0.1 mV) in the inferior, lateral or both leads with QRS slurring or notching.</AbstractText>The ERV pattern was present in 34 subjects (6.7%): 19 subjects (3.8%) displayed ERV in the lateral leads, 7 (1.4%) in the inferior leads, and 8 (1.6%) in both the lateral and inferior leads.</AbstractText>The prevalence of ERV within the healthy Turkish male population seems to be similar to the findings of previous population-based studies.</AbstractText> |
13,553 | Left atrial mechanical function and stiffness in patients with paroxysmal atrial fibrillation. | Abnormalities in the left atrial (LA) structure and function may develop in patients with paroxysmal atrial fibrillation (AF). We sought to determine the contribution of LA mechanical function, including LA stiffness, to AF by comparing patients with paroxysmal AF with normal control subjects, and to evaluate whether LA mechanical function and stiffness are related with the structural changes of LA.</AbstractText>Sixty-four paroxysmal AF patients (57 ± 13 years, 59% male) were studied, using a speckle tracking echocardiography, and were compared with 34 age-, gender-, and left ventricular (LV) mass-matched controls (53 ± 14 years, 61% male). LA volume indices, expansion index for reservoir function, active emptying fraction for contractile function, mitral annular velocities, and global longitudinal LA strain were measured. The ratio of E/e' to LA strain was used as an index of LA stiffness.</AbstractText>Patients with paroxysmal AF had similar LV volume indices, ejection fraction, and diastolic function, when compared with that of the normal controls. However, paroxysmal AF patients showed increased LA volume indices and decreased LA reservoir function, but similar contractile function. LA stiffness was increased in patients with paroxysmal AF than in the control subjects (0.40 ± 0.25 vs. 0.29 ± 0.10, p = 0.002), and was related with LA volume indices and reservoir function.</AbstractText>Patients with paroxysmal AF have decreased LA reservoir function and increased stiffness, in comparison with that of the control subjects. LA stiffness was significantly related with LA volume indices and reservoir function. LA stiffness can be used for the assessment of LA function in patients with paroxysmal AF.</AbstractText> |
13,554 | Incidence and predictors of phantom shocks in implantable cardioverter defibrillator recipients. | Implantable cardioverter defibrillators (ICDs) are designed to deliver shocks or antitachycardia pacing (ATP) in the event of ventricular arrhythmias. During follow-up, some ICD recipients experience the sensation of ICD discharge in the absence of an actual discharge (phantom shock). The aim of this study was to evaluate the incidence and predictors of phantom shocks in ICD recipients.</AbstractText>Medical records of 629 consecutive patients with ischaemic or dilated cardiomyopathy and prior ICD implantation were studied.</AbstractText>With a median follow-up of 35 months, phantom shocks were reported by 5.1 % of ICD recipients (5.7 % in the primary prevention group and 3.7 % for the secondary prevention group; p=NS). In the combined group of primary and secondary prevention, there were no significant predictors of the occurrence of phantom shocks. However, in the primary prevention group, phantom shocks were related to a history of atrial fibrillation (p=0.03) and NYHA class <III (p=0.05). In the secondary prevention group, there were no significant predictors for phantom shocks.</AbstractText>Phantom shocks occur in approximately 5 % of all ICD recipients. In primary prevention patients, a relation with a history of atrial fibrillation and NYHA class <III were significant predictors for the occurrence of phantom shocks. In the secondary prevention patients, no significant predictors were found.</AbstractText> |
13,555 | Atrial giant cell myocarditis: a distinctive clinicopathologic entity. | Giant cell myocarditis (GCM) typically causes fulminant heart failure, arrhythmias, or heart block, necessitating aggressive immunosuppression, ventricular assist device insertion, or cardiac transplantation. We describe a novel variant of GCM, primarily involving the atria, that displays distinctive clinical features and follows a more benign course than ventricular GCM.</AbstractText>We identified 6 patients (median age 67.5 years, 4 male) with atrial GCM in our pathology consultation practices from 2010 to 2012. Clinical history, imaging, and pathology materials were reviewed. Clinically, 4 patients had atrial fibrillation, 1 had acute heart failure, and 1 had incidental disease at autopsy. Among the 5 living patients, echocardiography revealed severe atrial dilatation (5 cases), mitral/tricuspid regurgitation (5), atrial mural thrombus (3), atrial wall thickening (2), and atrial hypokinesis (2). Ventricular function was preserved in all 5. Histological review of surgically resected atria showed giant cell and lymphocytic infiltrates, lymphocytic myocarditis-like foci, cardiomyocyte necrosis, and cardiomyocyte hypertrophy in all cases. Other features included interstitial fibrosis (5), poorly-formed granulomas (4), eosinophils (4), neutrophils (1), and vasculitis (1). Treatment consisted of steroids and cyclosporine (1), pacemaker placement for sick sinus syndrome (1), and supportive care (3). All 5 living patients returned to baseline exercise tolerance after 6 to 16 weeks of follow-up.</AbstractText>Atrial GCM represents a distinct clinicopathologic entity with a more favorable prognosis than classic ventricular GCM. This disorder should be included in the differential diagnosis of atrial dilatation, particularly when associated with atrial wall thickening. The utility of immunomodulatory therapy for this condition remains unknown.</AbstractText> |
13,556 | [QT prolongation and ventricular fibrillation caused by acute necrotising pancreatitis in a young female patient]. | Electrocardiographic alterations associated with acute pancreatitis (AP) have been known for decades. This association may be of particular importance in differential diagnosis, since authors have reported ECG abnormalities suggestive of myocardial infarction. The pathophysiological mechanism of these ECG changes has remained unclear to date. Only a few reports have been published on pancreatitis-induced QT prolongation and malignant arrhythmia. This case report describes the case history of a young female patient with acute pancreatitis accompanied with a substantial prolongation of the QT interval, resulting in recurrent ventricular tachycardia and fibrillation. A thorough cardiologic work-up (including coronary angiography and electrophysiology screen) ruled out other causes of malignant arrhythmia. The patient received an implantable cardioverter-defibrillator. Following resolution of the pancreatitis, the QT interval normalized and arrhythmia has not recurred during long-term follow-up. To the best knowledge of the authors, there is no case reports in the literature similar to that described in this paper. |
13,557 | Contribution of out-of-hospital factors to a reduction in cardiac arrest mortality after witnessed ventricular fibrillation or tachycardia. | Mortality rates in Osaka for cardiac arrest after witnessed ventricular tachycardia (VT) or ventricular fibrillation (VF) have decreased dramatically. We sought to estimate the contribution of changes in out-of-hospital care to this decrease.</AbstractText>We applied a previously validated statistical model, IMPACT, to data obtained from the Utstein Osaka Project, which registers all cardiopulmonary arrests in Osaka. The outcome was death within the first month after the arrest. Sensitivity analysis was conducted by simulating an increase in the use of public access defibrillators (PADs).</AbstractText>From 1999 through 2008, age- and sex-adjusted standardized 1-month mortality fell from 88.6% to 57.1%. There were 105 fewer deaths than expected in 2008 (295 deaths). The IMPACT model explained 62.5% of the decrease (67 deaths) in the 1-month mortality. The main contributors to the decrease in mortality were an increase in the use of biphasic waveform defibrillators, and a shortened time to first shock. These were partly offset by an increase in the administration of epinephrine by emergency medical services personnel. According to the simulation, an increase in PAD use from 1.9% to 34.4% would reduce mortality from the observed 57.1% to 49.5%.</AbstractText>Modeling suggests that improvement in out-of-hospital care accounted for approximately 60% of the decline in deaths following witnessed VT or VF arrests in Osaka between 1999 and 2008. Increased usage of PADs could further improve these outcomes.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,558 | Rescue pulmonary vein isolation for hemodynamically unstable atrial fibrillation storm in a patient with an acute extensive myocardial infarction. | New-onset atrial fibrillation in patients hospitalized for an acute myocardial infarction often leads to hemodynamic deterioration and has serious adverse prognostic implications; mortality is particularly high in patients with congestive heart failure and/or a reduced left ventricular ejection fraction. The mechanism of atrial fibrillation in the context of an acute myocardial infarction has not been well characterized and an effective treatment other than optimal medical therapy and mechanical hemodynamic support are expected.</AbstractText>A 71 year-old male with an acute myocardial infarction due to an occlusion of the left main coronary artery was treated with percutaneous coronary intervention. He had developed severe congestive heart failure with a left ventricular ejection fraction of 34%. The systemic circulation was maintained with an intraaortic balloon pump, continuous hemodiafiltration, and mechanical ventilation until atrial fibrillation occurred on day 3 which immediately led to cardiogenic shock. Because atrial fibrillation was refractory to intravenous amiodarone, beta-blockers, and a total of 15 electrical cardioversions, the patient underwent emergent radiofrequency catheter ablation on day 4. Soon after electrical cardioversion, ectopies from the right superior pulmonary vein triggered the initiation of atrial fibrillation. The right pulmonary veins were isolated during atrial fibrillation. Again, atrial fibrillation was electrically cardioverted, then, sinus rhythm was restored. Subsequently, the left pulmonary veins were isolated. The stabilization of the hemodynamics was successfully achieved with an increase in the blood pressure and urine volume. Hemodiafiltration and amiodarone were discontinued. The patient had been free from atrial fibrillation recurrence until he suddenly died due to ventricular fibrillation on day 9.</AbstractText>To the best of our knowledge, this is the first report of pulmonary vein isolation for a rescue purpose applied in a patient with hemodymically unstable atrial fibrillation complicated with an acute myocardial infarction. This case demonstrates that ectopic activity in the pulmonary veins may be responsible for triggering atrial fibrillation in the critical setting of an acute myocardial infarction and thus pulmonary vein isolation could be an effective therapeutic option.</AbstractText> |
13,559 | Regional and transmural dispersion of repolarisation in patients with Emery-Dreifuss muscular dystrophy. | The development of malignant ventricular arrhythmias is a possible feature in Emery-Dreifuss muscular dystrophy (EDMD) patients with normal left ventricular systolic function. This event may be the cause of sudden cardiac death in EDMD patients. QTc dispersion (QTc-D), JTc dispersion (JTc-D) and Tpeak-end dispersion (TDR) could reflect the physiological variability of regional and transmural ventricular repolarisation and could provide a substrate for life-threatening ventricular arrhythmias.</AbstractText>The current study was designed to evaluate the heterogeneity of ventricular repolarisation in EDMD patients.</AbstractText>Echocardiograms and electrocardiograms from 40 EDMD patients (age 20 ± 13) were evaluated and compared to those of 40 healthy age-matched controls.</AbstractText>The EDMD group, compared to the healthy control group, presented increased values of QTc-D (82.8 ± 44.1 vs. 53.3 ± 13.9, p = 0.003), JTc-D (73.6 ± 32.3 vs. 60.4 ± 11.1 ms, p = 0.001) and TDR (100.54 ± 19.06 vs. 92.15 ± 15.5 ms, p = 0.004). No correlation between QTc dispersion and ejection fraction (R = 0.2, p = 0.3) was found.</AbstractText>EDMD is associated with significantly increased regional and transmural heterogeneity of ventricular repolarisation, in the absence of impaired systolic and diastolic cardiac function.</AbstractText> |
13,560 | Determinants of patient survival rate after implantation of a cardioverter-defibrillator without resynchronisation capability. | Proper selection of patients at high risk for sudden cardiac death (SCD) and increasing use of implantable cardioverter-defibrillators (ICD) may contribute to improved survival among patients at the highest SCD risk.</AbstractText>To assess patient survival rate after implantation of an ICD without resynchronisation capability in our own patient population. Using uni- and multivariate analysis, we attempted to identify factors associated with significant worsening of patient survival rate.</AbstractText>From the population of patients who underwent ICD implantation for primary or secondary prevention of SCD in 2008-2010, we selected 376 patients with coronary artery disease or dilated cardiomyopathy (56 females, 320 males). Mean age was 66.1 ± 11.2 (range 22-89) years. ICD implantation protocols and in-hospital and outpatient records were reviewed retrospectively. We analysed the following clinical and procedural variables: age, gender, left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) functional class, mean heart rate (HR), QRS width, number of antiarrhythmic ICD interventions, type of SCD prevention, ICD type, performing defibrillation threshold testing (DFT) to establish defibrillation safety margin at ICD implantation, ventricular lead location, history of cardiovascular disease and arrhythmia, medications used (amiodarone, sotalol, beta-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, statins, loop diuretics, aldosterone antagonists). Date and cause of death were established by contacting patient family and/or the hospital to which the patient was admitted shortly before death or the general practitioner caring for the patient (verification of death certificates).</AbstractText>During the mean follow-up period of 447 ± 313 days, 46 patients died of known causes. Causes of death included sudden death in 16 patients, heart failure in 20 patients, and other causes in 10 patients (respiratory failure - 1, bleeding diathesis - 2, lung cancer - 3, colorectal cancer - 1, traffic accident - 1, and stroke - 2 patients). A comparison between primary and secondary prevention patients was performed. Mean QRS width <118 ms, resting HR < 78 bpm and LVEF >30% were significant cutoff values for improved survival as determined using the ROC curves. HR >78 bpm was observed in all SCD patients. In Kaplan-Meier univariate analysis including 27 parameters potentially influencing survival, 10 significant parameters were identified (type of prevention, presence of cardiomyopathy, ventricular tachycardia, HR, QRS width, LVEF, NYHA class, performing DFT, and statin and diuretic treatment). In Cox multivariate analysis, risk of death was increased with mean LVEV <30% (3-fold increase in risk), no DFT (2-fold increase in risk), NYHA class III or IV (3-fold increase in risk), and no statin use (2-fold increase in risk). Mean HR <78 bpm and QRS width <118 ms were independently related to an increased survival.</AbstractText>Death rate was higher in patients with LVEF <30%, NYHA class III or IV, no DFT performed and no statin treatment. In these patients, indications for cardiac resynchronisation therapy should be considered. HR <78 bpm and QRS width <118 ms are independent protective factors. HR >78 bpm was observed in all SCD patients. Sicker ICD patients live for a shorter time. The presence of atrial fibrillation, number of antiarrhythmic ICD interventions, ICD type and revascularisation approach did not affect survival/mortality.</AbstractText> |
13,561 | How to manage antiplatelet therapy for stenting in a patient requiring oral anticoagulants. | The optimal antiplatelet regimen for patients on oral anticoagulants undergoing coronary stenting continues to be controversial. It is not an insignificant problem, as 5-7 % of patients undergoing stenting are on oral anticoagulation for atrial fibrillation, a prosthetic valve, a recent left ventricular thrombus and recent pulmonary embolus. When given in combination with dual antiplatelet therapy, major bleeding is significantly increased, which is associated with an increased mortality. The balance between a reduction in stroke, stent thrombosis and myocardial infarction without a significant increase in major bleeding requires choosing therapy based upon the estimation of the risks of each adverse event. In patients with a low risk of stroke, such as those with atrial fibrillation and a CHADS(2) score of 0-1, dual antiplatelet therapy alone is sufficient. In those at moderate to high risk of stroke, dose-adjusted oral anticoagulation is needed. In those with the highest bleeding risk, use of a bare metal stent is strongly advised. In addition to bare metal stent use, the use of proton pump inhibitors, tight control of the international normalized ratio (INR) and only one month of dual antiplatelet therapy can reduce the bleeding risk without an increase in stroke or stent thrombosis. When a drug eluting stent (DES) is needed, a second generation DES should be used and triple therapy continued for 6 months (12 months if stent thrombosis risk is very high), followed by a single antiplatelet therapy and an oral anticoagulant. Since the newer antiplatelet agents and anticoagulants have not been studied in this setting, clopidogrel and warfarin should be used. Recently, the WOEST trial suggested that clopidogrel alone plus an oral anticoagulant resulted in an equal outcome with a significantly lower bleeding risk when compared to triple therapy. If confirmed, this regimen may become the standard of care. Presently, however, limiting the duration of triple therapy followed by clopidogrel and an oral anticoagulant seems the best option for the majority of patients to minimize bleeding risk without an increase in other adverse events. |
13,562 | Prognostic value of electromagnetic QRS fragmentation in survivors of sustained ventricular tachycardia or ventricular fibrillation compared with healthy controls. | Magnet field imaging (MFI) is a noninvasive method to determine cardiac electromagnetic activity.</AbstractText>This study aims to compare the electromagnetic QRS fragmentation index (eQFI) in survivors of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) to healthy individuals.</AbstractText>Twenty-five consecutive patients with documented sustained VT or VF who underwent a MFI investigation between December 2009 and October 2011 were compared with 25 age- and sex-matched healthy individuals.</AbstractText>Patients with documented VT or VF showed a trend to higher eQFI values compared with the control group (p = 0.06). This increase was mainly driven by VT/VF patients with ischemic cardiomyopathy (CMP) which was markedly elevated compared with the healthy controls (1.48 vs. 1.07; p = 0.01). In patients with nonischemic CMP or acute coronary syndrome, eQFI was not different from the healthy group.</AbstractText>Electromagnetic QRS fragmentation is increased in VT/VF patients with ischemic CMP but not in patients with ventricular arrhythmias of other origin. Further investigations in prospective cohorts should evaluate the prognostic value of electromagnetic QRS fragmentation in patients with ischemic heart disease to predict the occurrence of VT/VF and to guide therapy.</AbstractText> |
13,563 | Altered HCN4 channel C-linker interaction is associated with familial tachycardia-bradycardia syndrome and atrial fibrillation. | HCN4 channels are involved in generation, regulation, and stabilization of heart rhythm and channel dysfunction is associated with inherited sinus bradycardia. We asked whether dysfunctional HCN4 channels also contribute to the generation of cardiac tachyarrhythmias.</AbstractText>In a candidate gene approach, we screened 422 patients with atrial and/or ventricular tachyarrhythmias and detected a novel HCN4 gene mutation that replaced the positively charged lysine 530 with an asparagine (HCN4-K530N) in a highly conserved region of the C-linker. The index patient developed tachycardia-bradycardia syndrome and persistent atrial fibrillation (AF) in an age-dependent fashion. Pedigree analysis identified eight affected family members with a similar course of disease. Whole-cell patch clamp electrophysiology of HEK293 cells showed that homomeric mutant channels almost are indistinguishable from wild-type channels. In contrast, heteromeric channels composed of mutant and wild-type subunits displayed a significant hyperpolarizing shift in the half-maximal activation voltage. This may be caused by a shift in the equilibrium between the tonically inhibited nucleotide-free state of the C-terminal domain of HCN4 believed to consist of a 'dimer of dimers' and the activated ligand-bound tetrameric form, leading to an increased inhibition of activity in heteromeric channels.</AbstractText>Altered C-linker oligomerization in heteromeric channels is considered to promote familial tachycardia-bradycardia syndrome and persistent AF, indicating that f-channel dysfunction contributes to the development of atrial tachyarrhythmias.</AbstractText> |
13,564 | A case-matched comparative study of surgical radiofrequency (RF) ablation for patients with persistent or long-standing atrial fibrillation undergoing concomitant heart surgery. | Recent guidelines from the European Society of Cardiology suggest that surgical ablation should be considered in patients with atrial fibrillation (AF) who present for concomitant surgically correctable disease. This is a case-matched study of radiofrequency ablation during concomitant cardiac surgery versus lone surgery on patients with persistent and long-standing permanent AF.</AbstractText>Surgical ablation was performed in 21 patients, 14 with persistent and 7 with long-standing permanent AF. Patients with paroxysmal AF, recent onset persistent AF (<6 months), duration >6 years or left atrial diameter >8 cm were excluded. The study patients were matched 1-2 for age, sex, type of operation, type and duration of atrial fibrillation with 42 patients operated during the same period in the same department without ablation. The catheters used deliver continuously monitored radiofrequency energy, creating linear lesions on the inside of the arrested left and/or right atrial wall. Follow up was with regular outpatients' appointments and 24-hour ECG recordings at 6 and 12 months.</AbstractText>Sinus rhythm maintenance rate at discharge and 12-month follow up was significantly higher in the ablation group (12 months: 71% vs. 5%, p<0.01). The ablation group had significantly longer operative times. Mean ablation duration was 15.5 minutes (CI: 12-20). There were no deaths. There were no statistically significant differences in postoperative in-hospital stay, NYHA class, left atrial size, or left ventricular ejection fraction. All patients who maintained sinus rhythm during the ablation had echocardiographically confirmed left atrial systole at follow up.</AbstractText>Epicardial radiofrequency ablation in patients with persistent and long lasting permanent AF, who are being operated for concomitant cardiac surgical disease, is a safe, reproducible method with acceptable sustainability of sinus rhythm at medium-term follow up.</AbstractText> |
13,565 | Pneumonia: an arrhythmogenic disease? | Recent studies suggest that there is an increase in cardiovascular disease after pneumonia; however, there is little information on cardiac arrhythmias after pneumonia. The aims of this study were to assess the incidence of, and examine risk factors for, cardiac arrhythmias after hospitalization for pneumonia.</AbstractText>We conducted a national cohort study using Department of Veterans Affairs administrative data including patients aged ≥65 years hospitalized with pneumonia in fiscal years 2002-2007, receiving antibiotics within 48 hours of admission, having no prior diagnosis of a cardiac arrhythmia, and having at least 1 year of Veterans Affairs care. We included only the first pneumonia-related hospitalization, and follow-up was for the 90 days after admission. Cardiac arrhythmias included atrial fibrillation, ventricular tachycardia/fibrillation, cardiac arrest, and symptomatic bradycardia. We used a multilevel regression model, adjusting for hospital of admission, to examine risk factors for cardiac arrhythmias.</AbstractText>We identified 32,689 patients who met the inclusion criteria. Of these, 3919 (12%) had a new diagnosis of cardiac arrhythmia within 90 days of admission. Variables significantly associated with increased risk of cardiac arrhythmia included increasing age, history of congestive heart failure, and a need for mechanical ventilation or vasopressors. Beta-blocker use was associated with a decreased incidence of events.</AbstractText>An important number of patients have new cardiac arrhythmia during and after hospitalization for pneumonia. Additional research is needed to determine whether use of cardioprotective medications will improve outcomes for patients hospitalized with pneumonia. At-risk patients hospitalized with pneumonia should be monitored for cardiac arrhythmias during the hospitalization.</AbstractText>Published by Elsevier Inc.</CopyrightInformation> |
13,566 | Prevalence and prognostic significance of 'J waves' in patients experiencing ventricular fibrillation during acute coronary syndrome. | 'J waves' have been associated with idiopathic ventricular fibrillation (VF) and have also been described in patients with ischaemic VF.</AbstractText>Our aim was to determine whether inferior and/or lateral 'J waves' were associated with the occurrence of VF or in hospital mortality during acute coronary syndrome (ACS).</AbstractText>Fifty-three patients (mean age 52 ± 10 years) experienced cardiac arrest due to VF during the first 48 hours of an ACS. These patients were entered in a retrospective case-control study. The control group was matched for age and sex and included 106 patients who experienced an ACS but without VF.</AbstractText>'J waves' were more frequent in the study group than in the control group (62% vs. 39%; P=0.006). 'J waves' (odds ratio [OR] 3.3, 95% confidence interval [CI] 1.5-7.1; P=0.001) and left ventricular ejection fraction<40% (53% vs. 14%; P<0.001) (OR 7.9, 95% CI 3.5-18.0; P=0.001) were associated with VF. Inhospital mortality was 15.1% in the study group versus 0.9% in the control group (OR 18.7, 95% CI 2.2-157.5; P=0.008). VF (OR 18.3, 95% CI 2.3-835.9; P<0.001) and the presence of 'J waves' (OR 15.9. 95% CI 2.4-∞; P<0.001) were predictive of inhospital mortality. In patients who experienced VF, inhospital mortality was 24% when 'J waves' were observed and 0% when 'J waves' were absent (P=0.02).</AbstractText>Inferior and lateral 'J waves' were observed more frequently in patients who experienced cardiac arrest due to VF associated with ACS than in the absence of cardiac arrest and were associated with higher inhospital mortality.</AbstractText>Copyright © 2012 Elsevier Masson SAS. All rights reserved.</CopyrightInformation> |
13,567 | Laser extraction of pacemaker lead traversing a patent foramen ovale and the mitral valve. | Left ventricular lead misplacement is an infrequent complication of pacemaker or defibrillator lead insertion. It most commonly occurs through defects in the interatrial septum. Although patients may remain asymptomatic, the most common clinical complication is a thromboembolic event. Percutaneous technology has been described to safely remove misplaced leads. We present a case of a patient with a pacemaker lead in the left ventricle through a patent foramen ovale that was successfully extracted using excimer laser technology. |
13,568 | Characteristics and early and long-term outcome in patients with acute ischemic stroke and low ejection fraction. | We assessed the clinical characteristics of patients with acute ischemic stroke (AIS) with left ventricular ejection fraction (EF) ≤ 35% and investigated the association of low EF with early and long-term outcome.</AbstractText>A total of 2439 patients of the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) were selected. Demographics, risk factors, pre-stroke treatment, and clinical, radiological and metabolic variables in patients with and without low EF were compared. Functional independence (modified Rankin Score ≤ 2) and mortality were recorded 1 week up to 12 months from admission.</AbstractText>Low EF patients (n=119) were more commonly men, older, had higher rates of coronary artery disease and atrial fibrillation (AF), and more frequent pretreatment with anticoagulants, antiplatelets and antihypertensive agents. On admission, they presented with higher stroke severity and had lower values of systolic blood pressure, higher heart rate, and worse estimated glomerular filtration rate. Stroke-related disability and death rates were higher in low EF patients during follow-up (19.5% vs. 7.8% at 1 week, and 36.1% vs. 16.5% at 12 months). Increasing age, stroke severity, and AF were independent predictors of one-year mortality in these patients while prior use of statins had a favorable effect on early mortality.</AbstractText>AIS in patients with low EF is associated with older age, cardiac comorbidities, and more severe clinical presentation. Low EF can identify a subset of AIS patients at high risk of early and long-term functional disability and mortality.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,569 | FBN1 gene mutation characteristics and clinical features for the prediction of mitral valve disease progression. | Until today, FBN1 gene mutation characteristics were not compared with clinical features for the prediction of mitral valve disease progression.</AbstractText>Therefore, we conducted a study of 116 patients (53 men, 63 women aged 33 ± 15 years) with a causative FBN1 gene mutation and ≤ moderate mitral valve regurgitation at baseline.</AbstractText>During 7.4 ± 6.8 years 30 patients developed progression of mitral valve regurgitation ≥ 1 grade (primary endpoint), and 26 patients required mitral valve surgery (secondary endpoint). Cox regression analysis identified an association of atrial fibrillation (hazard ratio (HR)=2.703; 95% confidence interval (CI) 1.013-7.211; P=.047), left ventricular ejection fraction (HR=.970; 95%CI .944-.997; P=.032), indexed end-diastolic left ventricular diameter (HR=15.165; 95%CI 4.498-51.128; P<.001), indexed left atrial diameter (HR=1.107; 95%CI 1.045-1.173; P=.001), tricuspid valve prolapse (HR=2.599; 95%CI 1.243-5.437; P=.011), posterior leaflet prolapse (HR=1.075; 95%CI 1.023-1.130; P=.009), and posterior leaflet thickening (HR=3.368; 95%CI 1.265-8.968; P=.015) with progression of mitral valve disease, whereas none of the FBN1 gene mutation characteristics were associated with progression of mitral valve disease. However, Cox regression analysis identified a marginal relationship of FBN1 gene mutations located both in a transforming-growth-factor beta-binding protein-like (TGFb-BP) domain (HR=3.453; 95%CI .982-12.143; P=.053), and in the calcium-binding epidermal growth factor-like (cbEGF) domain (HR=2.909; 95%CI .957-8.848; P=.060) with mitral valve surgery, a finding that was corroborated by Kaplan-Meier analysis (P=.014; and P=.041, respectively).</AbstractText>Clinical features were better predictors of mitral valve disease progression than FBN1 gene mutation characteristics.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,570 | An alternative approach to explantation and exchange of the HeartWare left ventricular assist device. | Left ventricular assist device (LVAD) explantation and exchange is a relatively infrequent but potentially complex procedure. Patients requiring such procedures have multisystem suboptimal physiological reserve due to end-stage heart failure and are prone to complications. Less-invasive procedures are believed to facilitate postoperative recovery and early mobilization. We describe an alternative approach to explantation and exchange of the HeartWare LVAD through left thoracotomy.</AbstractText>Six patients (M = 4, F = 2, mean age = 49.16 years) underwent device explant/exchange or initial implant (explant = 2, exchange = 3, initial implant = 1) through left thoracotomy utilizing cardiopulmonary bypass and induced ventricular fibrillation (VF). The mean bypass time and mean VF arrest time were 82 and 3 min, respectively. A new outflow graft was anastomosed to the previous outflow graft in 3 cases of device exchange and to the descending aorta in 1 case of initial implant.</AbstractText>One patient died in the intensive care unit due to unrelated causes (gram-negative sepsis) after device exchange. All others were discharged alive and currently remain on follow-up. The mean length of hospital stay was 40.66 days.</AbstractText>On-pump approach through single thoracotomy incision is safe and equally suitable for device explant, exchange and initial implant. However, structural heart defects requiring surgical correction and the requirement of simultaneous right ventricular assist device are the limitations of this approach.</AbstractText> |
13,571 | Ruptured aortic dissection presenting with new onset atrial fibrillation. | We report this type A aortic dissection in both ascending and descending thoracic aorta presenting with new onset atrial fibrillation. CT images confirmed the final diagnosis. The mechanism may be due to compression of the left atrium by a large haematoma. |
13,572 | Wenxin Keli attenuates ischemia-induced ventricular arrhythmias in rats: Involvement of L‑type calcium and transient outward potassium currents. | Wenxin Keli is the first state‑sanctioned traditional Chinese medicine (TCM)-based antiarrhythmic drug. The present study aimed to examine whether long‑term treatment with Wenxin Keli reduces ischemia‑induced ventricular arrhythmias in rats in vivo, and if so, which mechanisms are involved. Male rats were treated with either saline (control group) or Wenxin Keli for 3 weeks and were subjected to myocardial ischemia for 30 min with assessment of the resulting ventricular arrhythmias. The L‑type calcium current (ICa,L) and transient outward potassium current (Ito) were measured by the patch clamp technique in normal rat cardiac ventricular myocytes. During the 30‑min ischemia, Wenxin Keli significantly reduced the incidence of ventricular fibrillation (VF) (P<0.05). The number of ventricular tachycardia (VT)+VF episodes and the severity of arrhythmias were significantly reduced by Wenxin Keli administration compared to the control group (P<0.05). In addition, Wenxin Keli inhibited ICa,L and Ito in a concentration‑dependent manner. These results suggest that long‑term treatment with Wenxin Keli may attenuate ischemia‑induced ventricular arrhythmias in rats and that ICa,L and Ito may be involved in this attenuation. |
13,573 | Effects of cardiac resynchronization therapy on left ventricular mass and wall thickness in mild heart failure patients in MADIT-CRT. | The effect of cardiac resynchronization therapy (CRT) on left ventricular wall thickness and left ventricular mass (LVM) is unknown.</AbstractText>To evaluate the effects of CRT on septal and posterior wall thickness (SWT and PWT) and LVM in patients with left bundle branch block (LBBB) and non-LBBB vs implantable cardioverter-defibrillator patients and to assess the relationship between CRT-induced changes and cardiac events.</AbstractText>We investigated 843 patients with LBBB and 366 patients with non-LBBB enrolled in the Multicenter Automatic Defibrillator Implantation Trial - Cardiac Resynchronization Therapy (MADIT-CRT) trial to analyze changes in SWT, PWT, and LVM at 12 months and subsequent outcome. The primary end point was heart failure or death; secondary end points included ventricular tachycardia, ventricular fibrillation, or death.</AbstractText>In LBBB patients, reduction in SWT, PWT, and LVM was more pronounced in CRT defibrillator (CRT-D) than in implantable cardioverter-defibrillator (SWT:-6.7% ± 4.4% vs-1.0% ± 1.9%; PWT:-6.4% ± 4.3% vs-0.8% ± 1.9%; LVM:-23.6% ± 9.9% vs-5.1% ± 5.1%; P<.001 for all). In CRT-D patients with non-LBBB, LVM reduction was less pronounced; however, changes in SWT and PWT were comparable. Changes in LVM correlated with changes in left ventricular end-diastolic volume. In CRT-D patients with LBBB, reduction in SWT and LVM was associated with reduction in heart failure/death (SWT: hazard ratio 0.94; 95% confidence interval 0.89-0.99 per percent change; P = .03) and ventricular tachycardia/ventricular fibrillation/death (SWT: hazard ratio 0.95; 95% confidence interval 0.91-1.00; P = .04). CRT-D patients with non-LBBB did not show favorable reduction in clinical or arrhythmic end points related to changes in SWT, PWT, or LVM.</AbstractText>CRT-D was associated with significant reduction in SWT, PWT, and LVM in patients with LBBB along with left ventricular volume changes and associated favorable clinical and arrhythmia outcomes.</AbstractText>Published by Elsevier Inc.</CopyrightInformation> |
13,574 | Physician perspectives and compliance with patient advance directives: the role external factors play on physician decision making. | Following passage of the Patient Self Determination Act in 1990, health care institutions that receive Medicare and Medicaid funding are required to inform patients of their right to make their health care preferences known through execution of a living will and/or to appoint a surrogate-decision maker. We evaluated the impact of external factors and perceived patient preferences on physicians' decisions to honor or forgo previously established advance directives (ADs). In addition, physician views regarding legal risk, patients' ability to comprehend complexities involved with their care, and impact of medical costs related to end-of-life care decisions were explored.</AbstractText>Attendees of two Mayo Clinic continuing medical education courses were surveyed. Three scenarios based in part on previously court-litigated matters assessed impact of external factors and perceived patient preferences on physician compliance with patient-articulated wishes regarding resuscitation. General questions measured respondents' perception of legal risk, concerns over patient knowledge of idiosyncrasies involved with their care, and impact medical costs may have on compliance with patient preferences. Responses indicating strength of agreement or disagreement with statements were treated as ordinal data and analyzed using the Cochran Armitage trend test.</AbstractText>Three hundred eighty-eight of 951 surveys were completed (41% response rate). Eighty percent reported they were likely to honor a patient's AD despite its 5 year age. Fewer than half (41%) would honor the AD of a patient in ventricular fibrillation who had expressed a desire to "pass away in peace." Few (17%) would forgo an AD following a family's request for continued resuscitative treatment. A majority (52%) considered risk of liability to be lower when maintaining someone alive against their wishes than mistakenly failing to provide resuscitative efforts. A large percentage (74%) disagreed that patients could not appreciate complexities surrounding their care while 69% agreed that costs should never impact a physician's decision as to whether to comply with a patient's AD.</AbstractText>Our findings highlight the impact, albeit small, external factors have on physician AD compliance. Most respondents based their decision on the clinical situation at hand and interpretation of the patient's initial wishes and preferences expressed by the AD.</AbstractText> |
13,575 | A case of left ventricular noncompaction accompanying fasciculo-ventricular accessory pathway and atrial flutter. | Left ventricular hypertrabeculation/noncompaction (LVHT) is an uncommon type of genetic cardiomyopathy characterized by trabeculations and recesses within the ventricular myocardium. LVHT is associated with diastolic or systolic dysfunction, thromboembolic complications, and arrhythmias, including atrial fibrillation, ventricular arrhythmias, atrioventricular block and Wolff-Parkinson-White syndrome. Herein, we describe a patient who presented with heart failure and wide-complex tachycardia. Echocardiography showed LVHT accompanied with severe mitral regurgitation. The electrophysiologic study revealed a fasciculo-ventricular accessory pathway and atrial flutter (AFL). The AFL was successfully treated with catheter ablation. |
13,576 | Preventive effectiveness of implantable cardioverter defibrillator in reducing sudden cardiac death in the Chinese population: a multicenter trial of ICD therapy versus non-ICD therapy. | Preventive Effectiveness of Implantable Cardioverter.</AbstractText>This prospective and multicenter trial of the implantable cardioverter-defibrillator (ICD) aimed to evaluate the mortality rate (including sudden cardiac death [SCD]) and the efficacy of ICD in Chinese patients with high risk of sudden death.</AbstractText>This trial was conducted in 31 centers in China. We enrolled 497 patients who fulfilled Class I indication for ICD (2002 ACC/AHA/NASPE guideline). All patients were followed-up at 3, 6, and 12 months. Clinical characteristics and echocardiographic parameters were collected at baseline and follow-up; Kaplan-Meier survival analysis was performed. Among 497 enrolled patients with Class I indication of ICD therapy, 112 (22.5%) agreed to and received ICD implantation (ICD group). The remaining 385 patients who were not available for ICD therapy were designated as the non-ICD group. During a mean follow-up of 11 ± 3 months, there were a total of 38 deaths, 2 in the ICD group with a mortality of 1.8% and 36 in the non-ICD group, with a mortality of 9.4% and 26 due to SCD. The overall survival rate was 93% at 3 months of follow-up, 91% at 6 months, and 89% at 12 months, with an incidence of SCD of 5%, 7%, and 8% at 3, 6, and 12 months, respectively.</AbstractText>In patients with Class I indication of ICD implantation, the total mortality and incidence of SCD were high. ICD therapy can effectively reduce the mortality in such patients.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,577 | Hemodynamic and metabolic parameters during prolonged cardiac arrest and reperfusion by extracorporeal circulation. | Extracorporeal membranous oxygenation (ECMO) is increasingly used in the management of refractory cardiac arrest. Our aim was to investigate early effects of ECMO after prolonged cardiac arrest. In fully anesthetized swine (48 kg, N=18) ventricular fibrillation (VF) was induced and untreated period (20 min) of cardiac arrest commenced, followed by 60 min extracorporeal reperfusion (ECMO flow 100 ml/kg.min). Hemodynamics, arterial blood gasses, plasma potassium, tissue oximetry (StO(2)) and cardiac (EGM) and cerebral (BIS) electrophysiological parameters were continuously recorded and analyzed. Within 3 minutes of VF hemodynamic and oximetry parameters fall abruptly while metabolic parameters destabilize gradually over 20 minutes peaking at pH 7.04 ± 0.05, pCO(2) 89 ± 14 mmHg, K(+) 8.5 ± 1.6 mmol/l. During reperfusion most parameters restore rapidly: within 3-5 minutes mean arterial pressure reaches >40 mmHg, StO(2)>50 %, paO(2)>100 mmHg, pCO(2)<50 mmHg, K(+)<5 mmol/l. EGMs mean amplitude peaks at 4.5 ± 2.4 min. Cerebral activity (BIS>60) reappeared in 5 animals after 87 ± 21 min. In 12/18 animals return of spontaneous circulation was achieved. In conclusions, ECMO provides rapid restitution of internal milieu even after prolonged arrest. However, despite normalization of global parameters full recovery was not guaranteed since cardiac and cerebral electrical activities were sufficiently restored only in some animals. More sensitive and organ specific indicators need to be identified in order to estimate adequacy of cardiac support devices. |
13,578 | Clinical implication of mitral annular plane systolic excursion for patients with cardiovascular disease. | Mitral annular plane systolic excursion (MAPSE) has been suggested as a parameter for left ventricular (LV) function. This review describes the current clinical application and potential implications of routinely using MAPSE in patients with various cardiovascular diseases. Reduced MAPSE reflects impaired longitudinal function and thus provides complementary information to ejection fraction (EF), which represents the global result of both longitudinal and circumferential contraction. Reduced long-axis deformation results from dysfunctional or stressed longitudinal myofibres due to endo- (and potentially epi-) cardial ischaemia, fibrosis, or increased wall stress. In patients with aortic stenosis, reduced MAPSE is suggestive of subendocardial fibrosis. Moreover, reduced MAPSE could be used as a sensitive early marker of LV systolic dysfunction in hypertensive patients with normal EF, where compensatory increased circumferential deformation might mask the reduced longitudinal deformation. In addition, reduced MAPSE was associated with poor prognosis in patients with heart failure, atrial fibrillation and post-myocardial infarction as well as in patients with severe aortic stenosis undergoing aortic valve replacement. Despite of the routine use of newer and more refined echocardiographic technologies nowadays, such as strain-rate imaging, speckle-tracking imaging, and 3D echocardiography, the use of MAPSE measurement is still especially helpful to evaluate LV systolic function in case of poor sonographic windows, since good imaging quality is required for most of the modern echocardiographic techniques with the exception of tissue Doppler imaging. |
13,579 | Use and benefits of public access defibrillation in a nation-wide network. | Automated External Defibrillators (AEDs) are known to increase survival after out-of-hospital cardiac arrest (OHCA). The aim of this study was to examine the use and benefit of public-access defibrillation (PAD) in a nation-wide network. We primarily sought to assess survival at 1 month but information about the circumstances of each OHCA is provided as well.</AbstractText>In this 28-month study, we assessed the use of 807 AEDs in Denmark. When an AED was deployed information about the circumstances of OHCA, the bystander, the AED and the victim's condition was obtained.</AbstractText>An AED was connected to an OHCA victim prior to the arrival of Emergency Medical Services (EMS) in 48 instances. Ten percent of bystanders were off-duty healthcare professionals. Shockable arrests (N=31, 70%) were significantly more likely to be witnessed (94% vs. 54%) to occur at sports facilities (74% vs. 31%), in relation to exercise (42% vs. 0%), and with improved 30-day survival (69% vs. 15%, p=0.001). Among those presenting with a shockable rhythm, 20 (65%) had Return of Spontaneous Circulation upon arrival of EMS and 8 (26%) were conscious, which emphasizes the diagnostic value of ECG downloads from AEDs. Survival could be determined in 42 of 44 patients with OHCA of cardiac origin, and was 52% (n=22, 95% CI [38-67]) and the Cerebral Performance Category was 1 (Good Cerebral Performance) in all survivors.</AbstractText>With a 30-day neurologically intact survival of 69% for patients with shockable rhythms, this study provides further evidence of the lifesaving potential of PAD.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,580 | Women hospitalized with atrial fibrillation: gender differences, trends and outcome from a 20-year registry in a Middle Eastern country (1991-2010). | Most of the published research on atrial fibrillation (AF) is limited to studies in the developed world and included mainly Caucasian patients. Data about women with AF among other ethnicities is very limited.</AbstractText>The aim of this study was to compare the clinical characteristics, treatment and outcome of women to men hospitalized with AF in a middle-eastern country.</AbstractText>Retrospective analysis of prospective registry of all patients hospitalized with AF in Qatar from 1991 through 2010 was made. Clinical characteristics, management, and outcomes of AF patients were compared according to gender.</AbstractText>During the 20-years period; 1417 women and 2432 men were hospitalized for AF. Women were 5 years older and more likely to have diabetes mellitus, hypertension, and chronic renal impairment and were also less likely to be current smokers and to have ischemic heart disease and impaired left ventricular function when compared to men. There was no gender preference in the use of anticoagulation. The prevalence of concomitant ischemic heart disease and hypertension increased, while the prevalence of valvular heart disease and heart failure decreased among patients hospitalized with AF over the study period. In-hospital mortality and stroke rates were comparable between the two groups.</AbstractText>Women hospitalized with atrial fibrillation were older in age and had higher prevalence of co-morbid cardiovascular risk factors compared to men whereas, mortality and stroke rates were comparable.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,581 | [Analysis of the clinical data of patients with acute coronary syndrome complicated by hemorrhage during hospitalization]. | To investigate the clinical characteristics of patients with acute coronary syndrome suffering hemorrhage during hospitalization.</AbstractText>The clinical symptoms, diagnostic and therapeutic characteristics and in-hospital outcome of 3807 inpatients who were recruited into SINO-GRACE study in China due to acute coronary syndrome from March, 2001 to December, 2007 were collected. Statistical methods were adopted to compare the differences in clinical data between hemorrhage group and non-hemorrhage group.</AbstractText>Hemorrhage had happened in 57 out of 3807 inpatients with the incidence of 1.50%. Five patients, which accounted for 9.6% of the overall hemorrhage cases, were fatal hemorrhage. Nine patients were intracranial hemorrhage with the incidence of 0.24%. There were 155 deaths among the 3807 patients, with an overall mortality rate of 4.1%. The mortality of hemorrhage accounted for 3.2% in overall mortality. Patients with one of the following factors were more apt to hemorrhage: > 70 years old, previous hemorrhage history, renal failure history, heart failure history and clopidogrel and glycoprotein (GP) IIb/IIIa receptor antagonist administration for coronary artery bypass grafting. Patients who developed hemorrhage might need prolonged hospitalization and were liable to develop heart-related adverse events, including re-infarction and sustained ventricular tachycardia/fibrillation after they were admitted in hospital over 24 hours.</AbstractText>Patients with acute coronary syndrome who underwent coronary artery bypass grafting, with advanced age, previous hemorrhage history, renal failure history, heart failure history or treated with clopidogrel and GP IIb/IIIa receptor antagonist are more vulnerable to hemorrhage.</AbstractText> |
13,582 | Cardiac injury in refractory status epilepticus. | We sought to describe the spectrum of cardiac injury in refractory status epilepticus (RSE).</AbstractText>We reviewed all patients with RSE between 1999 and 2011 at Mayo Clinic. RSE was defined as generalized convulsive or nonconvulsive status epilepticus (SE) that continued despite initial therapies. Exclusion criteria were age <18 years, anoxic SE, psychogenic SE, simple partial SE, absence SE, and repeat RSE. Patients were divided into those with (transient left ventricular [LV] dysfunction; electrocardiography [ECG] abnormality-new T-wave inversion, ST elevation or ST depression, or QTc prolongation; and/or elevated blood troponin T levels) versus those without evidence of cardiac injury.</AbstractText>We identified 59 consecutive patients with RSE. In 24 patients no cardiac-specific diagnostic studies were obtained. Twenty-two of the remaining 35 patients demonstrated markers of cardiac injury. General anesthesia was necessary for control of seizures in 31 of 35 patients for 10.5 ± 17.4 days. Twenty-three patients had troponin levels drawn at onset of SE, of which nine were abnormal. ECG findings at onset of SE included ST elevation (11.4%), ST depression (5.7%), new T-wave inversion (37.1%), and nonspecific ST changes (37.1%). Cardiac arrhythmias included ventricular tachycardia/fibrillation (11.4%), atrioventricular block (2.9%), atrial fibrillation/flutter (20.0%), sinus bradycardia (48.6%), and sinus tachycardia (65.7%). Intervention was required for cardiac arrhythmias in 42.9%. QTc was prolonged in 22.9% of patients. One patient met criteria for non-ST-elevation myocardial infarction (NSTEMI). Three of 14 patients evaluated with ECG during SE demonstrated reversible systolic dysfunction. In-hospital mortality was 34.3%. Outcome was worse in the group with markers of cardiac injury but the difference was not statistically significant (p = 0.14).</AbstractText>Markers of cardiac injury are common in RSE and may be underrecognized in this population. These disturbances may require specific treatment and are often reversible. Routine performance of ECG and troponin followed by an echocardiography in those with repolarization abnormalities is probably justified. This was a biased sample of patients with severe RSE who had cardiac studies performed. The prevalence of findings in this study refers to this subgroup only.</AbstractText>Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.</CopyrightInformation> |
13,583 | [Severe hypotension and ventricular fibrillation during combined general and epidural anesthesia in a patient on major tranquilizers]. | A 54-year-old man (height 155 cm, weight 49 kg) was scheduled for retroperitoneoscopic nephrectomy. He had a history of schizophrenia that had been controlled with propericiazine 10 mg and bromperidol 3 mg daily for 34 years. After induction of anesthesia, 1% mepivacaine 5 ml was administered via an epidural catheter. Blood pressure decreased 15 minutes later to 47/25 mmHg and heart rate dropped to 50 beats x min(-1). Ventricular fibrillation occurred despite titrated injection of ephedrine (40 mg total), phenylephrine (1 mg total), atropine (0.5 mg total), and rapid infusion of crystalloid and colloid solutions. Chest compression and defibrillation were required to restore spontaneous circulation. Surgery was cancelled and he was extubated 45 minutes later without any complications. These findings suggest that caution must be exercised when combining general and epidural anesthesia for patients on long-term major tranquilizers. In the event of refractory hypotension, the use of direct-acting vasoconstrictors such as noradrenaline or vasopressin should be considered. |
13,584 | Electrocardiographic abnormalities in medically screened military aircrew. | The European Society of Cardiology (ESC) recently published its updated recommendations for electrocardiogram (ECG) interpretation in athletes. It distinguishes ECG changes related to physical training (group 1 abnormalities) from training-unrelated changes (group 2) which may represent underlying electrical and structural heart disorders implicated in exercise related sudden cardiac death. This study sought to prospectively apply the ESC screening criteria to a large cohort of screened military aircrew.</AbstractText>This was a prospective observational study. The 12-lead ECGs of 868 consecutively evaluated healthy aircrew were analyzed for the presence of ESC-defined group 1 and 2 abnormalities.</AbstractText>The average age was 39.6 (11.2) yr (95.4% male). Overall, 402 (46.3%) of ECGs could be classified as entirely normal. However, 466 ECGs (53.7%) were abnormal. Group 1 abnormalities were identified in 400 (46.1%) persons with 66 (7.6%) persons classified as having group 2 abnormalities. The most commonly identified group 1 ECG changes were sinus bradycardia (32.5%), early repolarization (11.8%), and isolated voltage criteria of left ventricular hypertrophy (10.1%). The most commonly noted group 2 abnormalities were left-axis deviation/left anterior hemiblock (2.4%), T-wave inversion (1.6%), and ST-segment depression (1.3%). Prolongation of the QTC > 0.46 s was observed in 0.69% of ECGs.</AbstractText>The vast majority of ECGs performed in military aircrew could be classified as representing likely normal physiological changes. Training unrelated ECG changes, suggestive of possible genuine cardiac pathology, were observed in only a minority of persons who should be considered for further investigation.</AbstractText> |
13,585 | Signal-averaged and standard electrocardiography in patients with newly diagnosed epilepsy. | Antiepileptic drugs (AEDs) have been associated with cardiac conduction abnormalities and arrhythmias, predominantly in patients with predisposing cardiac conditions. Ventricular late potentials (VLPs) detected in the signal-averaged electrocardiogram (SAECG) may imply an increased risk of ventricular tachycardia or fibrillation. Twenty-six AED-naïve patients with newly diagnosed epilepsy and no clinical evidence of heart disease were examined with SAECG and standard ECG. Fifteen patients were treated with lamotrigine and ten with carbamazepine. No significant abnormality was found in the standard ECG or SAECG three to nine months after initiation of AED therapy. In one patient, a VLP was detected at baseline and subsequent MRI demonstrated significant right ventricular pathology; therefore, this patient was excluded from the rest of the study. This exclusion along with only newly diagnosed patients with a low total seizure count being included in the study may explain the lack of AED-induced electrocardiographic abnormalities in this patient cohort. |
13,586 | Trends in survival after in-hospital cardiac arrest. | Despite advances in resuscitation care in recent years, it is not clear whether survival and neurologic function after in-hospital cardiac arrest have improved over time.</AbstractText>We identified all adults who had an in-hospital cardiac arrest at 374 hospitals in the Get with the Guidelines-Resuscitation registry between 2000 and 2009. Using multivariable regression, we examined temporal trends in risk-adjusted rates of survival to discharge. Additional analyses explored whether trends were due to improved survival during acute resuscitation or postresuscitation care and whether they occurred at the expense of greater neurologic disability in survivors.</AbstractText>Among 84,625 hospitalized patients with cardiac arrest, 79.3% had an initial rhythm of asystole or pulseless electrical activity, and 20.7% had ventricular fibrillation or pulseless ventricular tachycardia. The proportion of cardiac arrests due to asystole or pulseless electrical activity increased over time (P<0.001 for trend). Risk-adjusted rates of survival to discharge increased from 13.7% in 2000 to 22.3% in 2009 (adjusted rate ratio per year, 1.04; 95% confidence interval [CI], 1.03 to 1.06; P<0.001 for trend). Survival improvement was similar in the two rhythm groups and was due to improvement in both acute resuscitation survival and postresuscitation survival. Rates of clinically significant neurologic disability among survivors decreased over time, with a risk-adjusted rate of 32.9% in 2000 and 28.1% in 2009 (adjusted rate ratio per year, 0.98; 95% CI, 0.97 to 1.00; P=0.02 for trend).</AbstractText>Both survival and neurologic outcomes after in-hospital cardiac arrest have improved during the past decade at hospitals participating in a large national quality-improvement registry. (Funded by the American Heart Association.).</AbstractText> |
13,587 | Renal sympathetic denervation provides ventricular rate control but does not prevent atrial electrical remodeling during atrial fibrillation. | Renal denervation (RDN) reduces renal efferent and afferent sympathetic activity thereby lowering blood pressure in resistant hypertension. The effect of modulation of the autonomic nervous system by RDN on atrial electrophysiology and ventricular rate control during atrial fibrillation (AF) is unknown. Here we report a reduction of ventricular heart rate in a patient with permanent AF undergoing RDN. Subsequently, we investigated the effect of RDN on AF-induced shortening of atrial effective refractory period, AF inducibility, and ventricular rate control during AF maintained by rapid atrial pacing in 12 pigs undergoing RDN (n=7) or sham procedure (n=5). During sinus rhythm, RDN reduced heart rate (RR-interval, 708±12 versus 577±19 ms; P=0.0021) and increased atrioventricular node conduction time (PQ-interval, 112±12 versus 88±9 ms; P=0.0001). Atrial tachypacing for 30 minutes increased AF inducibility and decreased AF cycle length. This was not influenced by RDN. RDN reduced ventricular rate during AF episodes by ≈24% (119±9 versus 158±19 bpm; P=0.0001). AF episodes were shorter after RDN compared with sham (12±3 versus 34±4 s; P=0.0091), but atrial effective refractory period was not modified by RDN. RDN reduced heart rate and reduced atrioventricular node conduction time during sinus rhythm and provided rate control during AF. AF-induced atrial electrical remodeling, AF inducibility, and AF cycle length were not modified, but duration of AF episodes was shorter after RDN. Modulation of the autonomic nervous system by RDN might provide rate control and reduce susceptibility to AF. Whether RDN may provide rate control in a larger number of patients with AF deserves further clinical studies. |
13,588 | Diagnosis, treatment, and outcome of giant-cell myocarditis in the era of combined immunosuppression. | Giant-cell myocarditis often escapes diagnosis until autopsy or transplantation and has defied proper treatment trials for its rarity and deadly behavior. Current therapy rests on multiple-drug immunosuppression but its prognostic influence remains poorly known. We set out to analyze (1) our experience in diagnosing giant-cell myocarditis and (2) the outcome of patients on combined immunosuppression.</AbstractText>We reviewed the histories, diagnostic procedures, details of treatment, and outcome of 32 consecutive patients with histologically verified giant-cell myocarditis treated in our hospital since 1991. Twenty-six patients (81%) were diagnosed by endomyocardial or surgical biopsies and 6 at autopsy or post-transplantation. Twenty-eight (88%) patients underwent endomyocardial biopsy. The sensitivity of transvenous endomyocardial biopsy increased from 68% (19/28 patients) to 93% (26/28) after up to 2 repeat procedures. The 26 biopsy-diagnosed patients were treated with combined immunosuppression (2-4 drugs) including cyclosporine in 20 patients. The Kaplan-Meier estimates of transplant-free survival from symptom onset were 69% at 1 year, 58% at 2 years, and 52% at 5 years. Of the transplant-free survivors, 10/17 (59%) experienced sustained ventricular tachyarrhythmias during follow-up and 3 received intracardiac defibrillator shocks for ventricular tachycardia or fibrillation.</AbstractText>Repeat endomyocardial biopsies are frequently needed to diagnose giant-cell myocarditis. On contemporary immunosuppession, two thirds of patients reach a partial clinical remission characterized by freedom from severe heart failure and need of transplantation but continuing proneness to ventricular tachyarrhythmias.</AbstractText> |
13,589 | Brugada syndrome: two decades of progress. | Two decades ago, a series of 8 idiopathic ventricular fibrillation patients who each had an abnormal ECG (right bundle branch block with coved-type ECG), but otherwise had normal hearts were described by Brugada and Brugada. Since then, the clinical entity has become known as Brugada syndrome (BS). Shortly thereafter, mutations of the SCN5A gene that encodes for the α-subunit of the sodium channel were found, galvanizing the field of ion channelopathies following in the footsteps of the breakthrough in long QT syndrome. Over the past 20 years, extensive research in this field has produced major progress toward better understanding of BS and the gaining of knowledge of the genetic background, pathophysiology and new management. Two consensus reports were published to help define the diagnostic criteria, risk stratification and management of BS patients. However, there are controversies. In this review, we will share our experiences of BS patients in Thailand and discuss advances in many aspects of the syndrome (ie, genetics and pathophysiology) and some of these pertinent controversies, as well as new treatment of the syndrome with catheter ablation. |
13,590 | Sudden cardiac arrest in ESRD patients. | End-stage renal disease (ESRD) carries a significant risk for sudden cardiac arrest (SCA), hospitalization and mortality. We present a case of a vintage hemodialysis patient who had a catastrophic event during his hemodialysis treatment - a sudden cardiac arrest. This case raises several important issues: First, patients with chronic kidney disease (CKD) (and particularly ESRD) are predisposed to an inordinate risk of SCA; second, the factors leading to SCA in CKD are unique; and lastly, it is of paramount importance to have basic life support training, crash carts and defibrillators in dialysis units. It also raises the important discussion regarding the role for automated implantable cardioverter defibrillators and medical therapy for the prevention of SCA in this population. |
13,591 | Arrhythmogenic right ventricular cardiomyopathy: the challenge of genetic interpretation in clinically suspected cases. | This is the case of a 43-year-old Caucasian man with frequent episodes of paroxysmal atrial fibrillation (AF) and normal resting electrocardiogram (ECG), who fulfilled two minor diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC): late potentials by signal-averaged ECG and regional right ventricular outflow tract (RVOT) dyskinesia with mildly dilated RVOT end-diastolic diameter. Genetic test results revealed a disease-associated missense mutation in DSC2 (p.E102K), adding a major diagnostic criterion according to recently published modified Task Force Criteria. However, 2 years after successful ablative therapy for AF, the patient remains completely asymptomatic, without any clinical signs of ARVC. Both ventricular and supraventricular arrhythmias had vanished after AF ablation. Our patient mainly suffered AF without significant ventricular arrhythmias, a very uncommon clinical presentation of ARVC. |
13,592 | Protective effect of K201 on isoproterenol-induced and ischemic-reperfusion-induced ventricular arrhythmias in the rat: comparison with diltiazem. | Ventricular arrhythmia (VA) is a risk for sudden death. Polymorphic ventricular tachycardia (VT) degenerating to ventricular fibrillation occurs subsequent to the prolongation of the QT interval following administration of catecholamines under Ca(2+) loading. Fatal VA also occurs in ischemia and ischemic-reperfusion. We compared the suppressive effect of K201 (JTV519), a multiple-channel blocker and cardiac ryanodine receptor-calcium release channel (RyR2) stabilizer, with that of diltiazem, a Ca(2+ )channel blocker, in 2 studies of isoproterenol-induced (n = 30) and ischemic-reperfusion-induced VAs (n = 38) in rats.</AbstractText>Adult male Wistar rats were administered 12 mg/kg/min calcium chloride (CaCl(2)) for 20 minutes and then 6 μg/kg/min isoproterenol was infused with CaCl(2) for a further 20 minutes. In other rats, the left coronary artery was ligated for 5 minutes followed by reperfusion for 20 minutes. K201 or diltiazem (both 1 mg/kg) was administered before infusion of the isoproterenol or induction of ischemia.</AbstractText>After administration of isoproterenol under Ca(2+) loading, fatal VA frequently occurred in the vehicle (9 of 10 animals, 90%) and diltiazem (8 of 10, 80%) groups, and K201 significantly suppressed the incidences of arrhythmia and mortality (2 of 10, 20%). In the reperfusion study, the incidence and the time until occurrence of reperfusion-induced VA and mortality were significantly suppressed in the K201 (2 of 15 animals, 13%) and diltiazem (1 of 9 animals, 11%) groups compared to the vehicle group (8 of 14 animals, 57%).</AbstractText>Induction of VA in an experimental model was achieved with a low dose of isoproterenol under Ca(2+) loading. K201 markedly suppressed both the isoproterenol-induced and the reperfusion-induced VAs, whereas diltiazem did not suppress the isoproterenol-induced VA. The results suggest that both VAs are related to early after depolarization (EAD) and indicate that K201 has the potential to suppress EAD by stabilizing RyR2 to mediate Ca(2+) release from the sarcoplasmic reticulum and acting as a multiple-channel blocker.</AbstractText> |
13,593 | The relationship between left ventricular scar and ventricular repolarization in patients with coronary artery disease: insights from late gadolinium enhancement magnetic resonance imaging. | The markers of ventricular repolarization corrected QT interval (QTc), QT dispersion (QTD) and Tpeak-to-Tend interval (Tpeak-end) have shown an association with sudden cardiac death (SCD) in the general population. However, their mechanistic relationship with SCD is unclear. The study aim was to evaluate the relationship between QTc, QTD, and Tpeak-end, and the extent and distribution of left ventricular (LV) scar in patients with coronary artery disease at high SCD risk.</AbstractText>We included 64 consecutive implantable cardioverter defibrillator (ICD) recipients (66 ± 11 years, 80% male, median left ventricular ejection fraction 30%) who had undergone late gadolinium enhancement cardiac magnetic resonance (CMR) imaging prior to device implantation over 4 years. Scar was quantified using the CMR images and characterized in terms of percent LV scar and number of LV segments with subendocardial/transmural scar. Repolarization parameters were measured on an electrocardiogram performed prior to ICD implantation. After adjustment for potential confounders there was a strong association between the number of limited subendocardial (1-25% transmurality) scar segments and QTc (P = 0.003), QTD (P = 0.002), and Tpeak-end (P = 0.008). However, there was no association between the repolarization parameters and percent LV scar or the amount of transmural scar. During a mean follow-up of 19 ± 10 months 19 (30%) patients received appropriate ICD therapy, but none of the repolarization parameters were associated with its occurrence.</AbstractText>In this pilot study there was a strong association between limited subendocardial LV scar and prolonged QTc, QTD, and Tpeak-end. However, there was no association between any of these repolarization markers and the delivery of appropriate ICD therapy.</AbstractText> |
13,594 | Ventricular pacing threshold after transthoracic external defibrillation with two different waveforms: an experimental study. | Although an increase in the ventricular pacing threshold (VPT) has been observed after administration of transthoracic shock for ventricular defibrillation, few studies have evaluated the phenomenon with respect to the defibrillation waveform energy. Therefore, this study examined the VPT behaviour after transthoracic shock with a monophasic or biphasic energy waveform.</AbstractText>Domestic Landrace male piglets implanted with a permanent pacemaker stimulation system were divided into three groups: no ventricular fibrillation (VF) induction and transthoracic shock with monophasic or biphasic energy (group I); VF induction, 1 min of observation without intervention, 2 min of external cardiac massage, and transthoracic shock with monophasic or biphasic energy (group II); and VF induction, 2 min of observation without intervention, 4 min of external cardiac massage, and transthoracic shock with monophasic or biphasic energy (group III). After external shock, the VPT was evaluated every minute for 10 min. A total of 143 experiments were performed. At the end of the observation period, groups I and II showed steady VPT values. Group III showed an increase in VPT with monophasic or biphasic external energy, with no difference between the external energy sources. The monophasic but not the biphasic waveform was associated with higher VPT values when the VF was longer.</AbstractText>Defibrillation does not have a significant impact on pacing threshold, but a longer VF period is related to a higher VPT after defibrillation with monophasic waveform.</AbstractText> |
13,595 | Large aneurysm of left coronary sinus of Valsalva presenting with effort-related ventricular fibrillation. | Sinus of Valsalva aneurysms are very rare and are often asymptomatic. Clinical manifestations depend on associated complications, most commonly rupture or dissection. We describe the unusual case of a 46-year old presenting with exercise-induced ventricular fibrillation due to extrinsic compression of the left coronary artery. We also describe the surgical correction by valve-sparing aortic root replacement. |
13,596 | Hemodynamic directed CPR improves short-term survival from asphyxia-associated cardiac arrest. | Adequate coronary perfusion pressure (CPP) during cardiopulmonary resuscitation (CPR) is essential for establishing return of spontaneous circulation. The objective of this study was to compare short-term survival using a hemodynamic directed resuscitation strategy versus an absolute depth-guided approach in a porcine model of asphyxia-associated cardiac arrest. We hypothesized that a hemodynamic directed approach would improve short-term survival compared to depth-guided care.</AbstractText>After 7 min of asphyxia, followed by induction of ventricular fibrillation, 19 female 3-month old swine (31±0.4 kg) were randomized to receive one of three resuscitation strategies: (1) hemodynamic directed care (CPP-20): chest compressions (CCs) with depth titrated to a target systolic blood pressure of 100 mmHg and titration of vasopressors to maintain CPP>20 mmHg; (2) depth 33 mm (D33): target CC depth of 33 mm with standard American Heart Association (AHA) epinephrine dosing; or (3) depth 51 mm (D51): target CC depth of 51 mm with standard AHA epinephrine dosing. All animals received manual CPR guided by audiovisual feedback for 10 min before first shock.</AbstractText>45-Min survival was higher in the CPP-20 group (6/6) compared to D33 (1/7) or D51 (1/6) groups; p=0.002. Coronary perfusion pressures were higher in the CPP-20 group compared to D33 (p=0.011) and D51 (p=0.04), and in survivors compared to non-survivors (p<0.01). Total number of vasopressor doses administered and defibrillation attempts were not different.</AbstractText>Hemodynamic directed care targeting CPPs>20 mmHg improves short-term survival in an intensive care unit porcine model of asphyxia-associated cardiac arrest.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,597 | What have we learned about patients with heart failure and preserved ejection fraction from DIG-PEF, CHARM-preserved, and I-PRESERVE? | Examination of patients with reduced and preserved ejection fraction in the DIG (Digitalis Investigation Group) trials and the CHARM (Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity) trials provides comparisons of outcomes in each of these types of heart failure. Comparison of the patients in these trials, along with the I-PRESERVE (Irbesartan in Heart Failure with Preserved Systolic Function Trial), with patients of similar age, sex distribution, and comorbidity in trials of hypertension, diabetes mellitus, angina pectoris, and atrial fibrillation provides even more interesting insights into the relation between phenotype and rates of death and heart failure hospitalization. The poor clinical outcomes in patients with heart failure and preserved ejection fraction do not seem easily explained on the basis of age, sex, comorbidity, blood pressure, or left ventricular structural remodeling but do seem to be explained by the presence of the syndrome of heart failure. |
13,598 | Diffuse ventricular fibrosis in atrial fibrillation: noninvasive evaluation and relationships with aging and systolic dysfunction. | The purpose of this study was to evaluate diffuse myocardial fibrosis of the left ventricle (LV) in patients with atrial fibrillation (AF).</AbstractText>Diffuse myocardial fibrosis is a hallmark of cardiomyopathy. Unlike replacement fibrosis, it is not visualized on delayed-enhancement cardiac magnetic resonance (CMR) imaging, but may be quantified with contrast-enhanced T(1) mapping methods. In atrial fibrillation (AF), it may be induced by arrhythmia or reflect pre-existing cardiomyopathy.</AbstractText>Ninety subjects underwent CMR using a clinical 1.5-T scanner: 23 controls, 40 paroxysmal AF patients, and 27 persistent AF patients. Cardiac morphology and function was evaluated from CMR cine imaging. A histologically validated T(1) mapping sequence was used to calculate post-contrast T(1) relaxation time (T(1) time) of the LV myocardium as an index of diffuse myocardial fibrosis.</AbstractText>Age was similar across controls, paroxysmal AF patients, and persistent AF patients (54 ± 12 years, 58 ± 9 years, and 56 ± 10 years, p = NS). Persistent AF patients had larger indexed left atrium volume (55 ± 18 ml vs. 41 ± 12 ml and 47 ± 14 ml) and lower ejection fraction (54 ± 10% vs. 65 ± 6% and 61 ± 8%) than controls and paroxysmal AF patients (p < 0.05). Post-contrast ventricular T(1) time differed across all groups (controls, 535 ± 86 ms; paroxysmal AF, 427 ± 95 ms; persistent AF, 360 ± 84 ms; p < 0.001). Univariate predictors of post-contrast ventricular T(1) time included age, sex, AF category, ejection fraction, LV mass, congestive heart failure, and body mass index. After multivariate analysis, age, AF category, and ejection fraction remained independent predictors.</AbstractText>Post-contrast ventricular T(1) mapping identifies diffuse LV fibrosis in patients with AF and provides new insights into the association between AF and adverse ventricular remodeling.</AbstractText>Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,599 | [Causes of non-response to cardiac resynchronization therapy in heart failure patients with permanent atrial fibrillation]. | To evaluate the long-term effects and analyze causes of non-response to cardiac resynchronization therapy (CRT) in heart failure (HF) patients with permanent atrial fibrillation (AF).</AbstractText>Thirty-three patients with HF and AF [29 men, mean age (61 ± 10) years, NYHA class III or IV, left ventricular ejection fraction (LVEF) ≤ 35%, QRS ≥ 120 ms in 31 cases] underwent bi-ventricular pacing (n = 26) or bi-ventricular pacing and atrioventricular node ablation (AVN-ablation, n = 7) were included in this study. Non-response was defined: the increase of left ventricular ejection fraction (LVEF) was less than 15%. Patients were followed-up for 4 years.</AbstractText>Six patients died during follow up. Non-responder to CRT was observed in 6 out of 27 survived patients (22.22%). Six out of 7 patients underwent AVN-ablation were in responder group and 1 in non-responder group. Comparing with responder group, the baseline LVEF was significantly higher (37% vs. 32%, P = 0.003), and the history of HF was significantly longer (6.3 years vs. 4.1 years, P = 0.039), pulmonary artery pressure was significantly higher (53 vs. 32 mm Hg, P = 0.027), bi-ventricular pacing percentage (BIVP%) was significantly lower (75.86% vs. 91.73%, P = 0.007) in non-responder group.</AbstractText>Higher LVEF, longer HF history, higher pulmonary artery pressure and lower BIVP% are factors linked with non-responses to CRT in this patient cohort. CRT plus AVN-ablation is associated with high response rate to CRT in this patient cohort.</AbstractText> |
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