Therapeutic Research

Abstract

A 57–year–old –male with dilated cardiomyopathy （left ventricular ejection fraction：LVEF 29％） was received right ventricular pacing（RVP） for symptomatic advanced atrioventricular block. Within the first 4 months, functional mitral regurgitation was getting so worse that it needed mitral valve replacement （MVR） and subsequently Cardiac Resynchronization therapy（CRT） upgrade was performed to reverse PICM. After CRT upgrading, QRS duration significantly shortened and clinical indicator such as NYHA functional class, electrophysiologic measurements （shorting paced QRS duration） and biological parameters（B–type natriuretic peptide） are substantially improved but only echocardiographic parameter is limited within LVEF ＜10％ despite of CRT upgrade. Careful consideration for both of pacing modality and underlying cardiac disease should be required at the first implantation. In the future, conduction system pacing like His –bundle pacing and left bundle branch area pacing can be alternative pacing strategy for RV septal pacing and CRT.