Publications by authors named "Michael Bernard"

Background: Secretoneurin, a member of the granin protein family, is associated with the risk of mortality in patients with acute and chronic heart failure. Secretoneurin may play an important role in cardiomyocyte calcium handling, suggesting that it may influence cardiac arrhythmia risk. We hypothesized that baseline and serial measurements of circulating secretoneurin are associated with the risk of incident ventricular tachyarrhythmias (VA) and death, and that serial measurement would provide prognostic information beyond baseline values.

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Importance: Atrial fibrillation and obesity are common, and both are increasing in prevalence. Obesity is associated with failure of cardioversion of atrial fibrillation using a standard single set of defibrillator pads, even at high output.

Objective: To compare the efficacy and safety of dual direct-current cardioversion (DCCV) using 2 sets of pads, with each pair simultaneously delivering 200 J, with traditional single 200-J DCCV using 1 set of pads in patients with obesity and atrial fibrillation.

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Introduction: Guidelines indicate primary-prevention implantable cardioverter-defibrillators (ICDs) for most patients with left ventricular ejection fraction (LVEF) ≤ 35%. Some patients' LVEFs improve during the life of their first ICD. In patients with recovered LVEF who never received appropriate ICD therapy, the utility of generator replacement upon battery depletion remains unclear.

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Introduction: Use of a novel magnetic sensor enabled optical contact force ablation catheter has been established to be safe and effective for treatment of symptomatic drug-refractory paroxysmal atrial fibrillation (AF) but has yet to be demonstrated in the persistent AF (PersAF) population.

Methods: PERSIST-END was a multicenter, prospective, nonrandomized, investigational study designed to demonstrate the safety and effectiveness of TactiCath™ Ablation Catheter, Sensor Enabled™(SE) (TactiCath SE) for use in the treatment of subjects with documented PersAF refractory or intolerant to at least one Class I/III AAD. The ablation strategy included pulmonary vein isolation and additional targets at physician discretion.

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Introduction: Heart failure (HF) is a major cause of morbidity and mortality, with nearly half of all HF-related deaths resulting from sudden cardiac death (SCD), most often from an arrhythmic event. The pathophysiologic changes that occur in response to the hemodynamic stress of HF may lead to increased arrhythmogenesis. Theoretically, medications that block these arrhythmogenic substrates would decrease the risk of SCD.

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Left atrial appendage (LAA) occlusion devices provided an acceptable and valid alternative to anticoagulation among patients with atrial fibrillation who carry high bleeding risk. Watchman device is non-inferior to oral anticoagulation to prevent cerebrovascular accidents. The presence of a longer distal portion of the older generation Watchman led to exclusion of patients with prohibitive anatomy of the LAA such as chicken-wing morphology or shallow LAA.

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Background: The EnSite Precision™ cardiac mapping system (Abbott) is a catheter navigation and mapping system capable of displaying the three-dimensional (3D) position of conventional and sensor-enabled electrophysiology catheters, as well as displaying cardiac electrical activity as waveform traces and dynamic 3D maps of cardiac chambers. The EnSite Precision™ Observational Study (NCT-03260244) was designed to quantify and characterize the use of the EnSite Precision™ cardiac mapping system for mapping and ablation of cardiac arrhythmias in a real-world environment and evaluate procedural outcomes.

Methods: A total of 1065 patients were enrolled at 38 centers in the USA and Canada between 2017 and 2018 and were followed for 12 months post procedure for arrhythmia recurrence, medication use, and quality-of-life changes.

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Atrial Fibrillation (AF) and heart failure (HF) with reduced ejection fraction (HFrEF) frequently coexist, resulting in significant morbidity and mortality. Therapeutic options for patients with AF and HFrEF are limited due to few antiarrhythmic drug (AAD) choices and historically equivocal effects of procedural interventions on mortality. However, recent randomized trials examining catheter ablation (CA) in AF patients with HFrEF have shown a beneficial effect on arrhythmic burden and HF symptoms, as well as an improvement in mortality.

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Aortic stenosis is the most common valvulopathy requiring replacement by means of the surgical or transcatheter approach. Transcatheter aortic valve replacement (TAVR) has quickly become a viable and often preferred treatment strategy compared to surgical aortic valve replacement. However, transcatheter heart valve system deployment not infrequently injures the specialized electrical system of the heart, leading to new conduction disorders including high-grade atrioventricular block and complete heart block (CHB) necessitating permanent pacemaker implantation (PPI), which may lead to deleterious effects on cardiac function and patient outcomes.

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Posterior wall isolation for recurrent atrial arrhythmia is a commonly used technique to achieve long-term freedom from atrial fibrillation. Despite the widespread use of posterior wall isolation, its long-term effects on left atrial function are unknown. Specifically, the effect of isolated atrial walls on stasis and risk of thrombus has not been established.

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Aims: Evidence links markers of systemic inflammation and heart failure (HF) with ventricular arrhythmias (VA) and/or death. Biomarker levels, and the risk they indicate, may vary over time. We evaluated the utility of serial laboratory measurements of inflammatory biomarkers and HF, using time-dependent analysis.

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Introduction: Sudden cardiac death is a substantial cause of mortality in patients with cardiomyopathy, but evidence supporting implantable cardioverter-defibrillator (ICD) implantation is less robust in nonischemic cardiomyopathy (NICM) than in ischemic cardiomyopathy. Improved risk stratification is needed. We assessed whether absolute quantification of stress myocardial blood flow (sMBF) measured by positron emission tomography (PET) predicts ventricular arrhythmias (VA) and/or death in patients with NICM.

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Article Synopsis
  • Class 1C antiarrhythmic drugs (AADs) are typically avoided in patients with coronary artery disease (CAD), but this study investigates their safety in those without clinical CAD but showing reduced coronary flow capacity (CFC).
  • In a pilot study, patients with atrial fibrillation (AF) treated with 1C AADs had similar survival rates to those not treated over a mean follow-up of 2 years.
  • The findings suggest that in patients with AF and reduced CFC but preserved heart function, 1C AADs may not increase mortality; however, further research is needed for conclusive results.
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Coronary vasospasm leading to variant angina is uncommon, and the condition is rare in pregnant patients. Many physiologic changes occur during pregnancy, but how these changes affect the spasticity of coronary arteries in patients predisposed to vasospasm is unknown. Vasospasm causing unstable arrhythmia from multiple foci can be difficult to treat.

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Objective: The objective of this study was to correlate early recurrence of atrial fibrillation (AF) after ablation with noninvasive imaging using cardiac computed tomography (CT).

Methods: CT image data of 260 patients who had undergone wide area circumferential ablation (WACA) between October 2005 and August 2010 as well as from 30 subjects in sinus rhythm without a history of AF (control group) were retrospectively analyzed. To evaluate early outcome of AF ablation, all AF patients underwent follow-up with a 30-day event monitor 3 to 4 months after ablation.

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In temperate deciduous forests of eastern USA, most earthworm communities are dominated by invasive species. Their structure and functional group composition have critical impacts on ecological properties and processes. However, the factors determining their community structure are still poorly understood, and little is known regarding their dynamics during forest succession and the mechanisms leading to these changes.

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Atrial fibrillation (AF) is the most common atrial arrhythmia in adults worldwide. As medical advancements continue to contribute to an ever-increasing aging population, the burden of atrial fibrillation on the modern health care system continues to increase. Therapies are also evolving, for treatment of the arrhythmia itself, and stroke risk mitigation.

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Aims: Several published investigations demonstrated that a longer T-peak to T-end interval (Tpe) implies increased risk for ventricular tachyarrhythmia (VT/VF) and mortality. Tpe has been measured using diverse methods. We aimed to determine the optimal Tpe measurement method for screening purposes.

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As the most common sustained arrhythmia in adults, atrial fibrillation (AF) is an established and growing epidemic. To provide optimal patient care, it is important for clinicians to be aware of AF's epidemiological trends, methods of risk reduction, and the various available treatment modalities. Our understanding of AF's pathophysiology has advanced, and with this new understanding has come advancements in prevention strategies as well as pharmacological and nonpharmacological treatment options.

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