Ventricular septal defect Doppler peak gradient underestimates right ventricular systolic pressure in the presence of right bundle branch block.

Estimation of the right ventricular systolic pressure (RVSP) using echocardiographically derived maximal instantaneous gradient across the ventricular septal defect is a well-utilized tool, which can potentially underestimate the RVSP in patients with conduction abnormalities as such its utility in these patients is questionable.