Echocardiographic assessment of mechanical dyssynchrony for CRT selection lacks RCT validation and should not alter current guidelines based on electrocardiogram criteria.
Does echocardiographic measurement of mechanical dyssynchrony better identify patients likely to benefit from CRT compared to ECG?
Echocardiographic assessment of mechanical dyssynchrony should not be used to select patients for CRT until proven beneficial in large randomized trials.
Cardiac resynchronization therapy (CRT) markedly reduces morbidity and mortality in patients with heart failure and prolonged QRS duration. Landmark trials have included over 4000 patients based on their electrocardiogram. A few small, observational, non-randomized, single centre studies of short duration have suggested that echocardiographic measurement of mechanical dyssynchrony may better identify patients likely to benefit from CRT. We objectively review the meaning and measurement of electrical and mechanical dyssynchrony, the strengths and weaknesses of echocardiographic indices of dyssynchrony, and the controversial issue of predicting response to treatment. We conclude that proposals to alter current guidelines for patient selection, and include echocardiography, are misguided. Echocardiographic assessment will only become credible and applicable to clinical practice once used to select patients for large prospective randomized trials which show an improvement in clinical outcome.
Hawkins et al. (Thu,) conducted a review in Heart failure with prolonged QRS duration. Echocardiographic assessment of mechanical dyssynchrony vs. Electrocardiogram (QRS duration) was evaluated. Echocardiographic assessment of mechanical dyssynchrony for CRT selection lacks RCT validation and should not alter current guidelines based on electrocardiogram criteria.