Septal bounce and septal shudder in constrictive pericarditis
Septal bounce is also called respirophasic ventricular septal shift [1, 2]. It is an early diastolic posterior motion of the interventricular septum. Septal bounce is a sign of ventricular interdependence noted in constrictive pericarditis. The sign may be seen on echocardiography, cardiac magnetic resonance imaging and cardiac computed tomography. Mechanism has been studied by simultaneous cardiac catheterization and echocardiography . Septal bounce was the most consistent sign among 39 cases of constrictive pericarditis evaluated by two independent observers in a study . Septal ‘bounce’ can occur in right ventricular pacing and left bundle branch block. But this occurs in early systole and has been called septal flash. Septal bounce occurred in 93% cases of constrictive pericarditis and 31% of other cases in a study . Ventricular septal shift has been included as one of the five Mayo Clinic echocardiographic criteria for constrictive pericarditis . Increased filling of right sided chambers and decreased filling of left sided chambers in inspiration causes a shift of the septum towards the left ventricle. In expiration, increased filling of left sided chambers and decreased filling of right sided chambers cause a shift of the septum towards the right ventricle. This is respirophasic ventricular septal shift. It typically needs a 10 beat long 2-D echo or M-Mode for documentation .
A systematic review noted almost universal presence of septal bounce on magnetic resonance imaging in constrictive pericarditis with sensitivity of 90-96% and specificity of 85-100% .
Septal shudder is an abnormal beat-to-beat septal motion, seen in constrictive pericarditis, but may also be seen in conduction abnormalities and post operative septum . Septal shudder occurred in 96% cases of constrictive pericarditis and 44% of other cases. Due to lack of specificity, septal shudder was not included in the Mayo clinic criteria for echocardiographic findings in constrictive pericarditis.