Cardiac Resynchronization Therapy

• Rationale - in pt with dyssynchronous LV and RV contraction, "resynchronizing" the ventricles will improve pump function and cardiac output, and also reverse remodeling.  Way it is done: in addition to standard pacing lead in RV, another lead is placed (through the coronary sinus) into the LV.
• Indications for CRT: 1) CHF with EF < 35%, 2) NYHA Class III or IV symptoms, and 3) Intraventricular conduction delay with QRS >120 msec
• Benefits: Improves symptoms, decreases hospitalizations, and improves mortality (CARE-HF, COMPANION trials)
• Often, an ICD is placed simultaneously, as indications for ICD often overlap with that for Bi-V pacing.

(Chanu Rhee MD, 7/30/10)