Abstract 2285: Acute and Chronic Improvement in Left Ventricular Diastolic Function Following Cardiac Resynchronization Therapy
Background: Cardiac resynchronization therapy (CRT) has been shown to result in improvements in left ventricular (LV) systolic function, but its effects on diastolic function are not well understood. Our aim was to test the hypothesis that CRT acutely improves LV diastolic function and that these benefits are sustained in chronic follow-up.
Methods: We studied 40 NYHA Class III–IV heart failure patients (65±10 yrs, ejection fraction 24±7%, QRS duration 166±26 ms, 62% ischemic) at baseline, 24 hours after CRT, and 6±3 mo. after CRT. A control group of 10 normal subjects were also studied. Quantitative pulsed wave and tissue Doppler measures of diastolic function included: mitral inflow peak E and A wave velocity, E deceleration time, mitral annular E′ velocity (septal and lateral sites) and estimation of LV filling pressure by E/E′.
Results: All CRT patients had baseline diastolic dysfunction, as expected: Deceleration Time = 163±53 ms, E′ = 3.4±1.6 cm/sec, E/E′ = 40±20, peak E wave = 1.11±0.3 m/sec, peak A wave = 0.5±.3 m/sec, (all p < 0.05 vs. controls). Diastolic function acutely improved following CRT: Deceleration Time = 218±52 ms*, E′= 4.3±1.8 cm/sec*, and E/E′ = 29±19*, peak E wave = 1.01±0.26 m/sec*, peak A wave = 0.7±.34 m/sec* (all p < 0.05 vs. baseline). These beneficial effects of CRT were sustained 6±3 month following CRT (all p < 0.05 vs. baseline).
Conclusion: CRT was associated with acute improvements in LV diastolic function. These improvements were sustained through chronic follow-up. These findings extend the understanding of beneficial effects of CRT on LV function.