Reversal of left ventricular remodeling by synchronous biventricular pacing in heart failure

Synchronous biventricular pacing is a new nonpharmacological supplemental t reatment of advanced heart failure associated with electromechanical conduc tion delay. However, the role of pacing on left ventricular remodeling is u nknown. Eleven patients with New York Heart Association Class III to IV hea rt failure, a left ventricular ejection fraction < 35%, and a QRS duration <greater than or equal to> 140 ms received a biventricular dual chamber pac emaker. Serial echocardiography, g-minute hall walk, and Minnesota Living w ith Heart Failure quality-of-life (QOL) questionnaire were performed before and after up to 3 months of pacing. At 3 months there was a significant in crease in fractional shortening (P < 0.001), ejection fraction (P < 0.001), and cardiac output (P < 0.05). The left ventricular end-diastolic volume ( 245 +/- 70 vs 185 +/- 37 mL, P < 0.05), end-systolic volume (209 +/- 69 vs 140 +/- 44 mL P < 0.05), and mitral regurgitation were reduced (P < 0.05), and diastolic filling time was lengthened (P < 0.05). There were also impro vements in heart failure symptoms, an increase in 6-minute walk distance, a nd a decrease in QOL scores. Synchronous biventricular pacing for 3 months was associated with hemodynamic improvements, reversal of left ventricular remodeling, and increase in left ventricular systolic function, and a decre ase in secondary mitral regurgitation.