Ventricular endocardial right bifocal stimulation in the treatment of severe dilated cardiomyopathy heart failure with wide QRS - VERBS

Description:

VERBS was a single-blinded crossover trial of two different right ventricular pacing modes in 39 patients with dilated cardiomyopathy, functional mitral regurgitation, and an indication for pacemaker therapy for advanced atrioventricular block.

Hypothesis:

In patients with dilated cardiomyopathy requiring pacemaker therapy for high-grade atrioventricular block, ventricular endocardial right bifocal pacing (VERBS) will improve echocardiographic indices of ventricular function and improve symptoms of heart failure and quality of life.

Study Design

Study Design:

Patients Enrolled: 39
NYHA Class: 3
Mean Follow Up: 1-6 months
Mean Patient Age: 25-82
Female: 38
Mean Ejection Fraction: 33

Patient Populations:

Dilated cardiomyopathy, functional mitral regurgitation, and an indication for pacemaker therapy for total or advanced atrioventricular block.

Primary Endpoints:

change in ejection fraction, change in cardiac output, quality of life evaluated by the Minnesota Living with Heart Failure Questionnaire

Secondary Endpoints:

change in left atrial area, change in functional mitral regurgitation, changes in transmitral flow rate and peak filling rate on Doppler echocardiography, QRS duration. Radionuclide angiocardiographic studies were performed in 6 patients.

Drug/Procedures Used:

All patients had endocardial pacemaker systems implanted with one ventricular lead in the right ventricular apex and one ventricular lead fixed in the high RV septum. Patients without atrial fibrillation also received a standard atrial lead. Patients subsequently underwent echocardiographic studies in 3 different ventricular pacing modes: (1) conventional RV apex pacing, (2) RV septal pacing, and (3) ventricular endocardial right bifocal pacing of both the RV septum and apex (VERBS). After initial echocardiographic evaluation, patients were randomized to standard RV apical pacing or VERBS in a single-blind manner. After one month, clinical status and quality of life were assessed, and patients' pacemakers were programmed to the alternate pacing mode and followed for another month.

Principal Findings:

QRS duration was 208 ms in conventional pacing mode compared with 157 ms in VERBS (p<0.05). Compared with conventional RV apical pacing mode, the VERBS pacing mode was associated with a significant increase in ejection fraction from 32.9% to 36.9%, an increase in cardiac output of 19.5%, a reduction in left atrial area of 11.9%, and a decrease in functional mitral regurgitation area of 32.3% (p<0.05 for all comparisons). In addition, the VERBS pacing mode was associated with improved echocardiographic indices of ventricular filling. Pacing of the RV septum alone was not significantly different from conventional RV apical pacing in most echocardiographic measures. In the randomized crossover portion of the trial, a significant improvement in quality of life was observed in patients after one month in the VERBS pacing mode compared with conventional RV apical pacing. Mean NYHA class was 3.1 after one month of conventional pacing and 1.9 after one month of VERBS (p<0.05 by Student's t-test). Radionuclinde angiocardiographic studies performed in 6 patients showed a reduction in systole duration and a longer diastolic filling time in VERBS pacing mode compared with conventional RV pacing or septal pacing modes.

Interpretation:

In patients with dilated cardiomyopathy requiring pacemaker therapy for high-grade atrioventricular block, VERBS was associated with improved echocardiographic indices of ventricular function, improved quality of life, and improved congestive heart failure symptoms when compared with conventional RV apical pacing. Limitations of this study include small sample size, single-blind design, and generilizability given the high percentage of patients with Chagas' disease.

References:

Pachon JC, Pachon EI, Albornoz RN, et al. Ventricular endocardial right bifocal stimulation in the treatment of severe dilated cardiomyopathy heart failure with wide QRS. Journal of Pacing and Clinical Electrophysiology 2001;24:1369-76.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Noninvasive Imaging, Valvular Heart Disease, Implantable Devices, EP Basic Science, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure, Echocardiography/Ultrasound, Mitral Regurgitation

Keywords: Chagas Disease, Mitral Valve Insufficiency, Cardiac Output, Single-Blind Method, Systole, Atrioventricular Block, Quality of Life, Heart Failure, Pacemaker, Artificial, Atrial Fibrillation, Ventricular Function, Diastole, Cardiomyopathy, Dilated, Echocardiography


< Back to Listings