Analysis of non-response causes and effect of cardiac resynchronization therapy in patients with advanced congestive heart failure

Objective:To investigate the non-response causes and effect of cardiac resynchronization therapy(CRT) in patients with advanced congestive heart failure by one year follow-up.Method:Twenty-four patients with advanced congestive heart failure underwent CRT with New York Heart association(NYHA) class Ⅲ and Ⅳ.There were 18 patients with dilated cardiomyopathy,2 patients with ischemic cardiomyopathy,one with sick sinus node syndrome with dual-chamber pacemaker implantation,and one with the third AVB with single-chamber pacemaker implantation.Before CRT and 12 months after CRT,the clinical and echocardiographic parameters and complication were analysed.Result:Twenty-three patients were successfully implanted the biventricular pacemaker.The success rate is 95.8%.Compared with before CRT,NYHA class of patients after 12 months's CRT decreased by 1.4 class(P0.01),left ventricular ejection fraction increased by 12%(P0.01),left ventricular end systolic volume decreased by 38%(P0.01),left ventricular synchrony index improved significantly(74.12 ms before CRT vs 40.78 ms after CRT,P0.01).The complications during and after implantation procedure included coronary sinus dissection in 1,left ventricular lead dislodgement in 2,phrenic nerve stimulation in 2,sudden cardiac death in 1.4 patient with non-response were complicated with atrial fibrillation,complete right bundle branch block,narraow QRS wave and diated cardiomyopathy with postero-lateral scar tissue.Conclusion:CRT could improve the cardiac function,correct the mechanical desynchronization and reverse left ventricular remodeling in patients with congestive heart failure,however,there were complications related to the implantation procedure and non-response possibilities.In order to improve the cost-effectiveness ratio of CRT,we must pay attention to the indication,standard procedure,follow-up,and program control.