The Clinical Evaluation Of Cardiac Resynchronization Therapy Optimized AV/VV Delay Dynamic For Patients With Chronic Heart Failure

Objective To evaluate the clinical effectiveness of cardiac resynchronization therapy optimized AV/VV delay. Methods the study included 26 patients who underwent implantation 0f biventricular pacemakers for chronic heart failure. the dynamic AV/VV delay was optimized on the day 1 week,6 months and 12-18 months after pacemaker implantation. The echocardiology and tissue doppler imaging ,ECG, 6MHW,the plasma BNP and the chest radiography were carried out on the day before and 1 week after pacemaker implantation,6 months later,12-18 months later. Results The best optimized AV delay was between 110ms and 140ms(122.69±9.62), and the best optimized VV delay was between 4ms and 24ms(13.08±5.07). The best optimized AV delay varied from -10ms to 10ms On different periods,and the best optimized VV delay changed from -4ms to 4 ms. Comparing the effectiveness 1 week after CRT with the day before CRT: The LVEF increased from (29.5±3.66)% to (31.69±3.00)%, The VTImr decreased from (18.97±3.81)cm to(16.04±3.64)cm; The septal-to-posterior wall motion delay(SPWMD) which represents left ventricular asynchrony dropped from (125.06±7.47)ms to (105.06±7.47)ms; The QRS interval decreased from(144.35±10.76)ms to (129.00±6.65) ms;6MHW upgraded from (278.46±12.55)m to (324.62±25.49)m;the plasma BNP degraded from(672.79±98.36)pg/ml to(484.03±106.02)pg/ml.Comparing the effectiveness of the day before and CRT Optimized AV/VV delay after 12-18months :the LVEF increased from(31.69±3.00)% to(39.54±3.39)%, the VTImr decreased from (16.04±3.64) cm to (8.67±1.18)cm; the SPWMD dropped from (105.06±7.47)ms to (101±7.56) ms; there is no difference in QRS intervals;the 6MHW upgraded from (324.62±25.49)m to (347.12±15.24)m;the plasma BNP degraded from (484.03±106.02) pg/ml to (98.41±8.57) pg/ml. The LVEDd dropped from (71.73±7.07)mm to (64.46±4.95) mm; The ratio between the heart and the chest decreased from (71±5)% to (63±4)%. Conclusion Optimized AV/VV delay of the pacemaker parameters enhanced the short-term, middle-term and long-term efficacy of CRT.