Cardiac resynch therapy (CRT) Biventricular (BiV) pacing

(JACC 2013;61:e6)

• 3-lead pacemaker (RA, RV, coronary sinus to LV); R >S in V1 suggests approp LV capture
• Synch LV fxn (↑ CO/EF, ↓ adv remodeling); ↓ HF sx & hosp, ↑ survival (NEJM 2010;363:2385)
• Indications: LVEF ≤35% + NYHA II–IV despite med Rx + SR + LBBB ≥150 ms (also reasonable if LBBB ≥120 ms, any non-LBBB ≥150 ms, or >40% V-pacing); mort. benefit w/ CRT-D only if LBBB (& QRS ≥130 ms) (NEJM 2014;370:1694) ? benefit in NYHA I–III, EF ≤50% w/ PPM indication for AVB (NEJM 2013;368:1585)