Pericardial Knock (Constrictive Pericarditis)

The early diastolic sound of pericardial constriction occurs slightly earlier than the average third heart sound. Its frequency is somewhat higher, allowing you to hear it throughout the precordium using the diaphragm and the bell. Common causes of pericardial constriction include prior cardiac surgery and uremic pericarditis. Copyright 2011 by the Texas Heart Institute at St. Luke's Episcopal Hospital.