Successful Cardiac Resynchronization Therapy in Dilated Cardiomyopathy with Narrow QRS Complex

Abstract

We experienced a case of non-ischemic cardiomyopathy with narrow QRS complex who responded to CRT. A 56-year-old man, with dilated cardiomyopathy admitted to our hospital due to congestive heart failure. Echocardiography showed diffuse hypokinetic left ventricular wall motion with a low EF of 22.7% and LV dyssynchrony was not obvious. ECG showed a narrow QRS complex of 110 ms. Current criterion of QRS duration for CRT is >120 ms, however, we decided to implant CRT-D for this patient since this patient had frequent non-sustained VTs and should be a candidate for ICD. NT-proBNP level decreased from 13957 to 1700 pg/ml after CRT. QRS duration on ECG did not show remarkable change before and after CRT. Echocardiography showed a reduction of MR from III to I–II. NYHA class has improved from IV to II at 2 month after CRT implantation. CRT provides a better prognosis even in a patient with narrow QRS complex. LV dyssynchrony could not be always detected by echocardiography. CRT would be useful beyond the current guidelines in some patients.