Biventricular pacing in severe heart failure patients reverses electromechanical dyssynchronization from apex to base.

Biventricular (BV) pacing is an emerging treatment for patients with severe dilated cardiomyopathy and ventricular asynchrony. Radionuclide angioscintigraphy has shown that BV can reduce activation delays between left (LV) and right ventricles (RV), but alterations of electromechanical asynchrony between the LV base and apex have not been previously described. Radionuclide angioscintigraphy with Tc99m red cell labeling was performed in 21 patients, 64 +/- 17 years of age, in NYHA functional Class III or IV, and with a mean QRS duration of 180 +/- 15 ms.