Cardiac resynchronization therapy in clinical responders: right ventricular echocardiographic changes at mid-term...

The objective of this study was to assess the mid-term effects of cardiac resynchronization therapy on systolic function and remodelling of the right ventricle in clinical responders and non-responders.

A biventricular system was implanted between July 2005 and May 2008 in 58 patients with heart failure NYHA class II-IV. At baseline, three and 15 months after implantation, the following parameters were determined: NYHA class, quality of life, six-minute walk test, echocardiography including assessment of right ventricular systolic function by tricuspid annular plane systolic excursion and by pulsed tissue Doppler imaging (myocardial peak systolic velocity was measured at the tricuspid annulus). We also assessed the presence of ventricular dyssynchrony.

There were no significant changes after three months of cardiac resynchronization therapy on right ventricular systolic function and remodelling in responders and non-responders. Among responders, we found a statistically significant improvement of right ventricular systolic function and also a significant decrease in the size of the right ventricle after 15 months of therapy (systolic excursion before therapy 17.8 +/- 4.0 mm vs. 19.4 +/- 3.7 mm, P < 0.05, after therapy; peak systolic velocity initially 11.9 +/- 2.9 cm/s vs 12.7 +/- 3.2 cm/s; right ventricle size before therapy 29.3 +/- 5.0 mm vs. 27.8 +/- 4.2 mm, P < 0.05, after therapy. These changes were not observed in non-responders.

Fifteen months after cardiac resynchronization therapy, we found a statistically significant improvement of right ventricular systolic function and a significant reduction of right ventricular size in responders to cardiac resynchronization therapy.