One-Year Landmark Analysis of the Effect of Beta-Blocker Dose on Survival After Acute Myocardial Infarction.

Background Although beta-blockers are recommended following myocardial infarction (MI), the benefits of long-term treatment have not been established. The study's aim was to evaluate beta-blocker efficacy by dose in 1-year post-MI survivors. Methods and Results The OBTAIN (Outcomes of Beta-Blocker Therapy After Myocardial Infarction) registry included 7057 patients with acute MI, with 6077 one-year survivors.

Performance of an ICD algorithm to detect lead noise and reduce inappropriate shocks.

Background: Implantable cardioverter-defibrillators (ICD) provide treatment for life-threatening ventricular tachyarrhythmias. Failure of the pace/sense conductor of an ICD lead can cause noise on the sensing electrogram (EGM) that may be misinterpreted as ventricular activity, triggering inappropriate therapy. An algorithm based upon the confirmation of ventricular activity from a far-field EGM has been developed to reduce inappropriate therapies resulting from this type of lead failure, while ensuring that appropriate therapy is delivered.

Prevalence of externalized conductors in Riata and Riata ST silicone leads: results from the prospective, multicenter Riata Lead Evaluation Study.

Background/objective: Following a class I recall of St. Jude Medical Riata/Riata ST silicone implantable cardioverter-defibrillator leads, we report on the phase I results of the Riata Lead Evaluation Study, a prospective, multicenter investigation to assess the prevalence of externalized conductors (ECs) and the electrical dysfunction in these leads.

Methods: We enrolled patients previously implanted with Riata/Riata ST leads and performed cinefluoroscopy using multiple views.

Postoperative performance of the Quartet® left ventricular heart lead.

Introduction: The Quartet(®) left ventricular (LV) lead is the first with 4 pacing electrodes (tip and 3 rings) that enables pacing from 10 different pacing vectors. Postoperative performance of this lead was evaluated in a prospective, nonrandomized, multicenter IDE study.

Methods: Patients with standard indications for CRT-D were enrolled.

Feasibility of using multivector impedance to monitor pulmonary congestion in heart failure patients.

Purpose: Pulmonary edema (PE) is associated with fluid accumulation in the lungs. Device-based impedance measurements have been used to detect fluid overload prior to hospitalization. However, studies have reported a high false positive rate (FPR).

Clinical performance of the St. Jude Medical Riata defibrillation lead in a large patient population.

Objective: The purpose of this large multicenter study was to evaluate the long-term reliability of an implantable cardioverter defibrillator (ICD) lead to determine the incidence of adverse events (AEs).

Background: A recent concern has been the performance of cardiac defibrillator leads. There have been conflicting reports regarding the rate of lead perforation and other AEs.

Performance of the St. Jude Medical Riata leads.

Background: Recent attention has been focused on the performance of high-voltage implantable cardioverter-defibrillator (ICD) leads. Lead-related adverse events can be caused by several factors, including patient characteristics, concomitant therapies, implantation technique, access site, and lead design. Few studies have included the number of patients and the follow-up duration necessary to characterize accurately the lead performance and the incidence of lead-related adverse events.

Cardiac-resynchronization therapy in heart failure with narrow QRS complexes.

Background: Indications for cardiac-resynchronization therapy (CRT) in patients with heart failure include a prolonged QRS interval (> or =120 msec), in addition to other functional criteria. Some patients with narrow QRS complexes have echocardiographic evidence of left ventricular mechanical dyssynchrony and may also benefit from CRT.

Methods: We enrolled 172 patients who had a standard indication for an implantable cardioverter-defibrillator.

Atrial overdrive pacing and incidence of heart failure-related adverse events in permanently paced patients.

Background: Atrial overdrive pacing algorithms may be effective in preventing or suppressing atrial fibrillation (AF). However, the maintenance of a heart rate incessantly faster than spontaneous could induce left ventricular (LV) dysfunction and promote heart failure (HF) on the long term.

Objective: This post hoc analysis examined the effects of a new overdrive algorithm on the incidence of HF-related adverse events in 411 patients enrolled in the ADOPT-A trial.

Acute evaluation of programmer-guided AV/PV and VV delay optimization comparing an IEGM method and echocardiogram for cardiac resynchronization therapy in heart failure patients and dual-chamber ICD implants.

Introduction: Intracardiac delay optimization of biventricular and dual-chamber pacing devices currently relies on time-consuming echocardiographic measurements. A novel intracardiac electrogram (IEGM) method for atrioventricular (AV/PV) and interventricular (VV) delay optimization was developed, which can be performed during routine device follow-up.

Methods And Results: In this prospective, nonrandomized, multi-center trial, patients previously implanted with St.

A new pacemaker algorithm for the treatment of atrial fibrillation: results of the Atrial Dynamic Overdrive Pacing Trial (ADOPT).

Objectives: The Atrial Dynamic Overdrive Pacing Trial (ADOPT) was a single blind, randomized, controlled study to evaluate the efficacy and safety of the atrial fibrillation (AF) Suppression Algorithm (St. Jude Medical Cardiac Rhythm Management Division, Sylmar, California) in patients with sick sinus syndrome and AF.

Background: This algorithm increases the pacing rate when the native rhythm emerges and periodically reduces the rate to search for intrinsic atrial activity.

Amiodarone versus implantable cardioverter-defibrillator:randomized trial in patients with nonischemic dilated cardiomyopathy and asymptomatic nonsustained ventricular tachycardia--AMIOVIRT.

Objectives: The purpose of this multicenter randomized trial was to compare total mortality during therapy with amiodarone or an implantable cardioverter-defibrillator (ICD) in patients with nonischemic dilated cardiomyopathy (NIDCM) and nonsustained ventricular tachycardia (NSVT).

Background: Whether an ICD reduces mortality more than amiodarone in patients with NIDCM and NSVT is unknown.

Methods: One hundred three patients with NIDCM, left ventricular ejection fraction < or =0.