Clinical study of wave intensity in assessing short-term effects of cardiac resynchronization therapy

Objective To investigate the clinical application of wave intensity (WI) technique in assessing the short-term effects of cardiac resynchronization therapy(CRT). Methods Sixteen patients with congestive heart failure treated with CRT were chosen. Before the implantation of CRT pacemaker and 1 week, 1 month,3 month after it,the diameters and volumes of left ventricle(LV) in the end-diastole and the end-systole were measured by echocardiography. LV ejection fractions(LVEF) were calculated by Simpson's way,and the variation ratio of left ventricular end-systolic volume(△ESV) was assessed each time after the CRT. The maximal rate of LV pressure rise (LVdP/dtmax) was assessed in the continuous-wave Doppler spectrum of mitral regurgitation. The magnitude of W1, and the length of R-W1 interval as well as W1-W2interval were recorded by WI technique applied on the left carotid artery of each patient. Results Compared to the data before CRT,W1 and W1-W2 interval were significantly higher in different period after CRT (P ＜0. 01). This result was conformed with echocardiographic remodeling data and LV systolic function.Conclusions WI provides a potential usage in conveniently and effectively assessing the CRT effects in short-term. Key words: Echocardiography;  Heart failure, congestive;  Cardiac resynchronization therapy;  Wave intensity