Myocardial tissue Doppler echocardiography and cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) is a promising technique for patients with end-stage, drug-refractory heart failure. Still 20-30% of the patients treated with CRT do not respond. Accordingly, the current selection criteria need to be refined, and it appears that demonstration of left ventricular dyssynchrony may be mandatory for response to CRT. Novel echocardiographic methods are currently investigated to detect left ventricular dyssynchrony and thereby improve the selection of candidates for CRT. In this brief review, these techniques will be discussed.