BACKGROUND: One third of patients with chronic heart failure have electrocardiographic evidence of a major intraventricular conduction delay, which may worsen left ventricular systolic dysfunction through asynchronous ventricular contraction. Uncontrolled studies suggest that multisite biventricular pacing improves hemodynamics and well-being by reducing ventricular asynchrony. We assessed the clinical efficacy and safety of this new therapy. METHODS: Sixty-seven patients with severe heart failure (New York Heart Association class III) due to chronic left ventricular systolic dysfunction, with normal sinus rhythm and a duration of the QRS interval of more than 150 msec, received transvenous atriobiventricular pacemakers (with leads in one atrium and each ventricle). This single-blind, randomized, controlled crossover study compared the responses of the patients during two periods: a three-month period of inactive pacing (ventricular inhibited pacing at a basic rate of 40 bpm) and a three-month period of active (atriobiventricular) pacing. The primary end point was the distance walked in six minutes; the secondary end points were the quality of life as measured by questionnaire, peak oxygen consumption, hospitalizations related to heart failure, the patients' treatment preference (active vs. inactive pacing), and the mortality rate. RESULTS: Nine patients were withdrawn from the study before randomization, and 10 failed to complete both study periods. Thus, 48 patients completed both phases of the study. The mean distance walked in six minutes was 22 percent greater with active pacing (399+/-100 m vs. 326+/-134 m, P<0.001), the quality-of-life score improved by 32 percent (P<0.001), peak oxygen uptake increased by 8 percent (P<0.03), hospitalizations were decreased by two thirds (P<0.05), and active pacing was preferred by 85 percent of the patients (P<0.001). CONCLUSIONS: Although it is technically complex, atriobiventricular pacing significantly improves exercise tolerance and quality of life in patients with chronic heart failure and intraventricular conduction delay.

Effects of Multisite Biventricular Pacing in Patients with Heart Failure and Intraventricular Conduction Delay

ContextCardiac resynchronization therapy (CRT) through biventricular pacing
is an effective treatment for heart failure (HF) with a wide QRS; however,
the outcomes of patients requiring CRT and implantable cardioverter defibrillator
(ICD) therapy are unknown.ObjectiveTo examine the efficacy and safety of combined CRT and ICD therapy in
patients with New York Heart Association (NYHA) class III or IV congestive
HF despite appropriate medical management.Design, Setting, and ParticipantsRandomized, double-blind, parallel-controlled trial conducted from October
1, 1999, to August 31, 2001, of 369 patients with left ventricular ejection
fraction of 35% or less, QRS duration of 130 ms, at high risk of life-threatening
ventricular arrhythmias, and in NYHA class III (n = 328) or IV (n = 41) despite
optimized medical treatment.InterventionsOf 369 randomized patients who received devices with combined CRT and
ICD capabilities, 182 were controls (ICD activated, CRT off) and 187 were
in the CRT group (ICD activated, CRT on).Main Outcome MeasuresThe primary double-blind study end points were changes between baseline
and 6 months in quality of life, functional class, and distance covered during
a 6-minute walk. Additional outcome measures included changes in exercise
capacity, plasma neurohormones, left ventricular function, and overall HF
status. Survival, incidence of ventricular arrhythmias, and rates of hospitalization
were also compared.ResultsAt 6 months, patients assigned to CRT had a greater improvement in median
(95% confidence interval) quality of life score (–17.5 [–21 to
–14] vs –11.0 [–16 to –7], P =
.02) and functional class (–1 [–1 to –1] vs 0 [–1
to 0], P = .007) than controls but were no different
in the change in distance walked in 6 minutes (55 m [44-79] vs 53 m [43-75], P = .36). Peak oxygen consumption increased by 1.1 mL/kg
per minute (0.7-1.6) in the CRT group vs 0.1 mL/kg per minute (–0.1
to 0.8) in controls (P = .04), although treadmill
exercise duration increased by 56 seconds (30-79) in the CRT group and decreased
by 11 seconds (–55 to 12) in controls (P<.001).
No significant differences were observed in changes in left ventricular size
or function, overall HF status, survival, and rates of hospitalization. No
proarrhythmia was observed and arrhythmia termination capabilities were not
impaired.ConclusionsCardiac resynchronization improved quality of life, functional status,
and exercise capacity in patients with moderate to severe HF, a wide QRS interval,
and life-threatening arrhythmias. These improvements occurred in the context
of underlying appropriate medical management without proarrhythmia or compromised
ICD function.

https://jamanetwork.com/journals/jama/articlepdf/1108361/JOC30332.pdf

Combined cardiac resynchronization and implantable cardioversion defibrillation in advanced chronic heart failure: the MIRACLE ICD Trial.

https://cdr.lib.unc.edu/downloads/zc77ss357

ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices--summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/NASPE Committee to Update the 1998 Pacemaker Guidelines).

Background Hypertrophic cardiomyopathy is a genetic disease associated with a risk of ventricular tachyarrhythmias and sudden death, especially in young patients. Methods We conducted a retrospective multicenter study of the efficacy of implantable cardioverter–defibrillators in preventing sudden death in 128 patients with hypertrophic cardiomyopathy who were judged to be at high risk for sudden death. Results At the time of the implantation of the defibrillator, the patients were 8 to 82 years old (mean [±SD], 40±16), and 69 patients (54 percent) were less than 41 years old. The average follow-up period was 3.1 years. Defibrillators were activated appropriately in 29 patients (23 percent), by providing defibrillation shocks or antitachycardia pacing, with the restoration of sinus rhythm; the average age at the time of the intervention was 41 years. The rate of appropriate defibrillator discharge was 7 percent per year. A total of 32 patients (25 percent) had episodes of inappropriate discharges. In the g...

Efficacy of Implantable Cardioverter–Defibrillators for the Prevention of Sudden Death in Patients with Hypertrophic Cardiomyopathy

Background Dual-chamber (atrioventricular) and single-chamber (ventricular) pacing are alternative treatment approaches for sinus-node dysfunction that causes clinically significant bradycardia. However, it is unknown which type of pacing results in the better outcome. Methods We randomly assigned a total of 2010 patients with sinus-node dysfunction to dual-chamber pacing (1014 patients) or ventricular pacing (996 patients) and followed them for a median of 33.1 months. The primary end point was death from any cause or nonfatal stroke. Secondary end points included the composite of death, stroke, or hospitalization for heart failure; atrial fibrillation; heart-failure score; the pacemaker syndrome; and the quality of life. Results The incidence of the primary end point did not differ significantly between the dual-chamber group (21.5 percent) and the ventricular-paced group (23.0 percent, P=0.48). In patients assigned to dual-chamber pacing, the risk of atrial fibrillation was lower (hazard ratio, 0.79; 9...

/pdf/ventricular-pacing-or-dual-chamber-pacing-for-sinus-node-5ddzwjdwxs.pdf

Ventricular pacing or dual-chamber pacing for sinus-node dysfunction

The publication of major studies dealing with the natural history of bradyarrhythmias and tachyarrhythmias and major advances in the technology of pacemakers and implantable cardioverter-defibrillators (ICDs) has mandated this revision of the 1991 ACC/AHA Guidelines for Implantation of Pacemakers and Antiarrhythmia Devices.

This executive summary appears in the April 7, 1998 issue of Circulation. The full text of the guidelines, including the ACC/AHA Class I, II, and III recommendations, is published in the April 1998 issue of the Journal of the American College of Cardiology. Reprints of both the executive summary and the full text are available from both organizations.

Following extensive review of the medical literature and related documents previously published by the American College of Cardiology, the American Heart Association, and the North American Society for Pacing and Electrophysiology, the writing committee developed recommendations that are evidence based whenever possible.

Evidence supporting current recommendations is ranked as level A if the data were derived from multiple randomized clinical trials involving a large number of individuals. Evidence was ranked as level B when data were derived from a limited number of trials involving comparatively small numbers of patients or from well-designed data analysis of nonrandomized studies or observational data registries. Evidence was ranked as level C when consensus of expert opinion was the primary source of recommendation. The committee emphasizes that for certain conditions for which no other therapies are available, the indications for device therapies are based on years of clinical experience as well as expert consensus and are thus well supported, even though the evidence was ranked as level C.

These guidelines include expanded sections on selection of pacemakers and ICDs, optimization of technology, cost, and follow-up of implanted devices. The follow-up sections are relatively brief because in many instances the type and frequency of follow-up examinations …

ACC/AHA Guidelines for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices: Executive Summary A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Pacemaker Implantation)

A. Conill

Papers

ACC/AHA Guidelines for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices: Executive Summary A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Pacemaker Implantation)

心臓ペースメーカー及び抗不整脈デバイスの植込みに関するacc/ahaガイドラインアメリカ合衆国心臓学会/アメリカ心臓協会の診療ガイドラインに関するタスクフォースの報告(ペースメーカー植込みに関する委員会)

ACC/AHA Guidelines for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices

Acc/aha guidelines for implantation of cardiac pacemakers and anti arrhythmia devices : executive summary

A. Conill

Papers

ACC/AHA Guidelines for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices: Executive Summary A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Pacemaker Implantation)

心臓ペースメーカー及び抗不整脈デバイスの植込みに関するacc/ahaガイドライン アメリカ合衆国心臓学会/アメリカ心臓協会の診療ガイドラインに関するタスクフォースの報告(ペースメーカー植込みに関する委員会)

ACC/AHA Guidelines for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices

Acc/aha guidelines for implantation of cardiac pacemakers and anti arrhythmia devices : executive summary

心臓ペースメーカー及び抗不整脈デバイスの植込みに関するacc/ahaガイドラインアメリカ合衆国心臓学会/アメリカ心臓協会の診療ガイドラインに関するタスクフォースの報告(ペースメーカー植込みに関する委員会)