A randomized controlled trial to evaluate the safety and efficacy of cardiac contractility modulation in patients with systolic heart failure: rationale, design, and baseline patient characteristics.

Cardiac contractility modulation (CCM) signals are nonexcitatory electrical signals delivered during the cardiac absolute refractory period that enhance the strength of cardiac muscular contraction. Prior research in experimental and human heart failure has shown that CCM signals normalize phosphorylation of key proteins and expression of genes coding for proteins involved in regulation of calcium cycling and contraction. The results of prior clinical studies of CCM have supported its safety and efficacy.

Contemporary pacemakers: what the primary care physician needs to know.

Pacemaker therapy is most commonly initiated because of symptomatic bradycardia, usually resulting from sinus node disease. Randomized multicenter trials assessing the relative benefits of different pacing modes have made possible an evidence-based approach to the treatment of bradyarrhythmias. During the past several decades, major advances in technology and in our understanding of cardiac pathophysiology have led to the development of new pacing techniques for the treatment of heart failure in the absence of bradycardia.

Remote magnetic versus manual catheter navigation for ablation of supraventricular tachycardias: a randomized, multicenter trial.

Introduction: The potential benefits of remote robotic navigation for catheter ablation procedures have not been demonstrated in controlled clinical trials. The purpose of this study was to compare remote magnetic catheter navigation to manual navigation for the ablation of common supraventricular arrhythmias.

Methods And Results: Patients with supraventricular arrhythmias due to atrioventricular (AV) nodal reentry, accessory pathways, or undergoing AV junctional ablation for complete heart block were randomized in a 3:1 ratio between magnetic (Niobe system and Helios II catheter, Stereotaxis, Inc.

Clinical judgment versus decision analysis for managing device advisories.

Introduction: Implantable cardioverter-defibrillator (ICD) and pacemaker (PM) advisories may have a significant impact on patient management. Surveys of clinical practice have shown a great deal of variability in patient management after a device advisory. We compared our management of consecutive patients in a single large university practice with device advisories to the "best" patient management strategy predicted by a decision analysis model.

Regional endocardial left atrial voltage and electrogram fractionation in patients with atrial fibrillation.

Introduction: Heterogeneities in electrophysiological properties may contribute to the development of atrial fibrillation, and regional disparities in endocardial voltage in the left atrium have been related to arrhythmogenic mechanisms. This study aimed at investigating endocardial voltage in different regions of the left atrium in patients with atrial fibrillation (AF).

Methods And Results: Thirty-six patients (aged 56 +/- 7 years, 10 female) scheduled for circumferential ablation for paroxysmal AF were studied.

Benefit of primary prevention implantable cardioverter-defibrillators in the setting of chronic kidney disease: a decision model analysis.

Introduction: Primary prevention ICD trials have excluded patients with CKD. Comorbidities and lower life expectancy in patients with CKD make the benefit of primary prevention ICD implantation uncertain.

Methods: A decision analysis model was devised to evaluate the risks and benefits of implantable cardioverter-defibrillators (ICD) implantation in patients with chronic kidney disease (CKD) who meet current criteria for a primary prevention ICD.

Implantable cardiac defibrillator lead failure or myopotential oversensing? An approach to the diagnosis of noise on lead electrograms.

The appearance of noise on electrograms (EGMs) recorded from the lead of an implantable cardioverter-defibrillator (ICD) may be owing to oversensing of myopotentials, insulation breach, conductor coil fracture, loose set screw, or electromagnetic interference from an external source. The extraneous noise may lead to inappropriate shocks or inhibition of pacing. We describe two cases of pectoral myopotentials oversensing in patients with ICD and an approach to distinguish among the various extraneous noises recorded on EGMs.

Reduced ejection fraction, sudden cardiac death, and heart failure death in the mode selection trial (MOST): implications for device selection in elderly patients with sinus node disease.

Unlabelled: Sudden Cardiac Death in Elderly Pacemaker Patients.

Background: The purpose of this study was to describe the incidence and predictors of sudden cardiac death (SCD) and heart failure (HF) death, and coexisting indications for ICDs and CRT, in patients with sinus node disease (SND) treated with pacemakers.

Methods And Results: Baseline variables were used to predict SCD and HF death among 1,135 patients in the Mode Selection Trial, a 6-year trial of pacing mode in SND.

Severe atrioventricular decoupling, uncoupling, and ventriculoatrial coupling during enhanced atrial pacing: incidence, mechanisms, and implications for minimizing right ventricular pacing in ICD patients.

Unlabelled: AV Decoupling During Enhanced AAIR Pacing.

Background: Enhanced AAI/R pacing minimizes right ventricular pacing but may permit or induce AV decoupling (AV-DC) due to unrestricted AV intervals (AVIs). The purpose of this study was to characterize and quantify AVI behavior in a randomized trial of enhanced AAI/R pacing in ICD patients.

Decision-making, emotional distress, and quality of life in patients affected by the recall of their implantable cardioverter defibrillator.

Aims: We sought to investigate whether patients with implantable cardioverter defibrillators (ICDs) were suffering from emotional distress related to the recent United States Food and Drug Administration (FDA) recalls, to better understand their decision process related to device replacement, and to assess any impact of recall on quality of life (QOL).

Methods And Results: Thirty-one patients experiencing device recalls answered questions regarding their knowledge about the recall and their decision whether to replace the device. Fifty patients whose devices were not recalled reported demographic data.

Gender disparity in the use of cardiac resynchronization therapy in the United States.

Background: Although several studies have shown the effectiveness of cardiac resynchronization therapy (CRT) for advanced congestive heart failure (CHF), gender differences in utilization of CRT are not known.

Methods: We used the Healthcare Cost and Utilization Project (HCUP) to study national rates for admissions due to CHF along with procedures for initial CRT implantation, including both CRT-defibrillator (CRT-D) and CRT-pacemakers (CRT-P) during the years of 2002-2004. Chi-square tests were used for comparison between number of women and men.

Clinical outcome of left atrial ablation for paroxysmal atrial fibrillation is related to the extent of radiofrequency ablation.

Background: The exact mechanism of eliminating atrial fibrillation (AF) by catheter ablation techniques is not known. We investigated whether the extent of atrial damage conferred by radiofrequency lesions is a predictor of success after ablation, regardless of the method employed for ablation.

Methods: Ninety consecutive patients with paroxysmal AF subjected to ostial-antral pulmonary vein isolation (n = 41) or circumferential (n = 49) catheter ablation were studied.

Long-term follow-up after radiofrequency catheter ablation for atrial fibrillation.

Aims: Data on long-term follow-up of patients who have undergone catheter ablation for atrial fibrillation (AF) are very limited. This report aimed at presenting clinical outcome and AF-free survival after pulmonary vein (PV) isolation over an extended (>3 years) follow-up period.

Methods And Results: Thirty-nine patients subjected to PV isolation for paroxysmal AF were followed-up for at least 3 years according to a strict protocol.

Sensing failure associated with the Medtronic Sprint Fidelis defibrillator lead.

Introduction: The diameter of implantable cardioverter-defibrillator (ICD) leads has become progressively smaller over time. However, the long-term performance characteristics of these smaller ICD leads are unknown.

Methods: We retrospectively evaluated 357 patients who underwent implantation of a Medtronic Sprint Fidelis defibrillating lead at two separate centers between September 2004 and October 2006.

The role of pacemakers in the management of patients with atrial fibrillation.

Pacemakers have an important role in the major strategies for the management of atrial fibrillation, rate control and rhythm control. Of all the current non-pharmacologic therapies for atrial fibrillation, the use of pacemakers impacts the largest number of patients. Pacemakers are used to facilitate medical management of atrial fibrillation with rate control agents and anti-arrhythmic drugs.