In search of the perfect indicators of left ventricular mechanical dyssynchrony

Excerpt

Cardiac resynchronization therapy (CRT) is indicated for the treatment of patients with advanced heart failure (HF) symptoms, a left ventricular (LV) ejection fraction (EF) ≤35 %, and prolonged QRS duration.1 Unfortunately, the sole use of these current patient selection parameters leads to implantation in an estimated third of patients for whom improvement is not demonstrable.2 Alternatively, using QRS duration as a surrogate for electrical dyssynchrony may lead to the inappropriate exclusion of large segments of the HF population that may benefit from CRT. In recent years, there has been a push towards towards investigating non-invasive imaging methods to accurately define LV mechanical dyssynchrony and thus improve patient selection for CRT. …