[Total atrioventricular block as the primary clinical manifestation of undiagnosed aortic dissection].

We describe the case of a 54-year-old male who was examined due to light chest pain experienced the previous day. The man was admitted to the cardiology division for the presence of a complete atrioventricular block. On admission the echocardiogram showed a large aortic regurgitation not present two years earlier. Suspecting an aortic dissection we performed a transesophageal echocardiography and a contrast computerized tomography: the two examinations were negative. The next days the patient had two episodes of acute pulmonary edema so he was transferred to the regional reference hospital where an hemodynamic unit and cardiac surgery division were available. There, he repeated a transesophageal echocardiography which was negative. The man had aortic valve replacement without angiography for his very critical condition. The surgeon identified a small aortic dissection, just above the aortic valve plane, which was responsible for valve leaflets prolapse and aortic regurgitation; the hematoma deepened towards the interatrial septum and atrioventricular junction justifying the atrioventricular block. In conclusion, a small aortic dissection can offer an atypical picture, and in this condition even very valuable diagnostic techniques may fail the diagnosis.