Acute severe increase in afterload as a new mechanism for "stunning" in the right ventricle

Abstract

Purpose: To determine the effects of an acute severe afterload increase on right ventricular (RV) function. Methods: Twelve patients (16±11 years old) with moderate or severe pulmonary regurgitation after Fallot correction in childhood underwent percutaneous pulmonary valve implantation (PPVI). Deployment of the valve with a balloon results in a complete occlusion of the RV outflow tract (RVOT) for a mean time of 15 seconds. Echocardiograms were taken before (Echo1) and immediately after (Echo2) balloon occlusion as well as at the end of the procedure (Echo 3). Conventional echocardiographic and tissue Doppler based deformation indices of the RV were assessed. Results: See figure. Acute severe increase in RV afterload during balloon inflation resulted in a significant decrease in fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE) and RV free wall deformation (Strain), the latter showing induced pronounced post-systolic shortening (PSS). All parameters had returned close to baseline at the end of the procedure. ![Figure][1] Conclusion: Acute severe increase in RV afterload induces a transient myocardial dysfunction which recovers within minutes. The underlying mechanism is unclear, but observed changes have similarities with ischemic stunning. Further studies are needed to explore this phenomenon. [1]: pending:yes