Impacts of acute severe pulmonary regurgitation on right ventricular geometry and contractility assessed by tissue-Doppler echocardiography.

AIMS: Little is known of the impact of acute right ventricular (RV) volume overload on RV function. We assessed the impact of acute severe pulmonary regurgitation (PR) on global and regional RV function by applying novel quantitative echocardiographic markers of myocardial performance in an animal model.

METHODS AND

RESULTS

Transthoracic echocardiography, including tissue-Doppler echocardiography for the evaluation of regional longitudinal function, was performed immediately before and after induction of severe PR by deployment of a stent in the pulmonary valve annulus of 32 farm pigs. Acute PR was associated with significant changes in RV geometry illustrated by an increase in RV diameter and area by 22 and 32%, respectively, P < 0.001 for both, and the eccentricity index increased by 21% in end-diastole, P < 0.0001. RV radial function as assessed by RV short-axis fractional shortening increased by 18%, P = 0.03, whereas other measures of RV ejection fraction by longitudinal function remained unchanged. There were no changes in the longitudinal basal myocardial isovolumic acceleration, peak systolic velocity, strain rate, or strain.

CONCLUSION

The RV seems to accommodate well to acute severe PR. No changes in global or regional longitudinal contractility or deformation were observed despite significant changes in the cardiac chamber geometry. An increase in radial shortening may imply that the RV compensates by increasing radial contraction as an adjunct to dilatation.