Effects of cardiac resynchronization therapy on time-domain T wave alternans in patients with chronic heart failure / 中南大学学报(医学版)

ABSTRACT

OBJECTIVE@#To study the effects of cardiac resynchronization therapy (CRT) with different pacing rates and modes on MTWA.
@*METHODS@#From March, 2012 to October, 2014, 43 patients who received CRT or CRT-D implantation in the first affiliated hospital, Nanjing Medical University were studied. Time-domain MTWA test were assessed following CRT implantation. MTWA was measured at 90 min(-1) and 110 min(-1) by treadmill exercise test with GE CASE 8000 during CRT-on (BIV biventricular) and CRT-off (RA right atrial) pacing modes. The comparsion of MTWA values between different pacing mode and pacing rates were analyzed. According to the heart function classification the patients were divided into 3 groups. The correlation between MTWA and cardiac function was analyzed.
@*RESULTS@#MTWA-AAI was significantly increased compared to MTWA-BIV at the pacing rate of 90 min(-1) [(11.27±9.94) µV vs (7.09±7.16) µV, P=0.001]. The value of MTWA at pacing rate of 110 min(-1) was nonsignificantly higher than MTWA during AAI pacing [(16.91±12.51) µV vs (15.58± 10.97) µV, P=0.517]. The value of MTWA at pacing rate of 110 min(-1) was higher than MTWA at pacing rate of 90 min(-1) during AAI or BIV (P<0.05). MTWA-AAI and MTWA-BIV in group of NYHA IV were higher than those in group of NYHA II (P<0.05).
@*CONCLUSION@#Biventricular pacing mode at lower pacing rates can significantly attenuate MTWA. The value of MTWA is associated with the severity of CHF.