Utility of Echocardiography for Cardiac Resynchronization Therapy：What Should Be Evaluated by Sonographers in Clinical Settings?

Abstract

Cardiac Resynchronization Therapy（CRT）is the therapeutic option for patients with advanced heart failure. We can detect characteristic left ventricular abnormal movements called “septal flash” and “apical shuffle motion” as a visual feature of dyssynchrony by echocardiography, and CRT can be effective for patients with such findings suggesting dyssynchrony. Such findings detected by echocardiography can give us information on potential candidates for CRT. We can also evaluate the myocardium itself in the posterior and lateral walls where the left ventricular lead is usually fixed, and it can be inferred that myocardial scar in lead-positioned site has poor effect for CRT. Therefore, echocardiography can help us decide lead position. It can also be used to evaluate the disappearance of dyssynchronization by evaluating left ventricular size / volume and, contractility ability after CRT. Assessment of right-side cardiac function is also important, because deterioration of tricuspid annular plane systolic excursion（TAPSE）and the presence of pulmonary hypertension predict poor prognosis after CRT. In this article, we explain the importance of and some points of evaluation in echocardiography before and after CRT in the clinical setting.