His Bundle Pacing Versus Coronary Sinus Pacing for Cardiac Resynchronization Therapy
The goal of this study is to compare the effectiveness of pacing from a physiologic His bundle (HB) lead position versus with the standard coronary sinus (CS) lead position in subjects with heart failure undergoing cardiac resynchronization therapy (CRT). While placement of left ventricular leads via the coronary sinus has anatomic limitations, we hypothesis that the achievement of QRS narrowing with His bundle capture will be superior for improving systolic function by echocardiographic indices (ejection fraction and strain) and quality of life and decreased rehospitalization and mortality.
• Patients at least 18 years of age
• LV systolic dysfunction with LVEF ≤ 35%
• Evidence of intraventricular conduction delay with QRS duration \> 120 msec
• NYHA Class II, III, and ambulatory Class IV heart failure with either ischemic or nonischemic cardiomyopathy and patients with NYHA Class I symptoms and ischemic cardiomyopathy
• Left ventricular ejection fraction (LVEF) ≤ 35%, sinus rhythm (SR), left bundle-branch block (LBBB) morphology, and QRS duration ≥ 150 msec, and NYHA Class II, III, or ambulatory Class IV patients on goal-directed medical therapy (GDMT) \[Class I\]
• LVEF ≤ 35%, SR with LBBB with QRS 120-149 msec on GDMT \[Class IIa\]
• LVEF ≤ 35%, SR with non-LBBB with QRS ≥ 150 msec on GDMT \[Class IIa\]
• LVEF ≤ 35%, in AF if medication or AV nodal ablation will allow near 100% pacing \[Class IIa\]
• LVEF ≤ 35% undergoing new or replacement device with anticipated \>40% ventricular pacing on GDMT \[Class IIa\]
• LVEF ≤ 30%, ischemic etiology of HF, SR with LBBB ≥ 150 msec and NYHA Class I symptoms on GDMT \[Class IIb\]
• LVEF ≤ 35%, SR with non-LBBB with QRS 120-149 msec, NYHA Class III/ambulatory Class IV HF on GDMT \[Class IIb\] LVEF ≤ 35%, SR with non-LBBB with QRS ≥ 150 msec, NYHA Class II HF on GDMT \[Class IIb\]