Role of Left Ventricular Strain Imaging in Patients Undergoing Cardiac Resynchronization Therapy

Abstract

Lack of therapeutic response in nearly 30% of patients undergoing cardiac resynchronization therapy (CRT) remains a major therapeutic challenge. Given the role of echocardiography in detecting mechanical dyssynchrony, extensive research has been undertaken to identify the echocardiographic predictors of CRT response. After the initial setback, the interest in this field has renewed with the introduction of speckle-tracking echocardiography (STE) for quantifying myocardial deformation. Several newer and potentially useful indices of mechanical dyssynchrony have been developed. In addition, the non-invasive assessment of myocardial work has also become feasible and many of the myocardial work indices have shown considerable promise in the initial studies. The strain imaging may also help in identifying the optimum site for left ventricular lead placement. This review summarizes the current understanding regarding the role of left ventricular strain imaging in patients undergoing CRT.

Keywords

• apical rocking
• mechanical dyssynchrony
• septal flash
• systolic stretch index
• wasted work