Abstract 3541: Acute Aortic Dissection With Massive Pericardial Effusion in Cardiopulmonary Arrest on Arrival
The natural history of aortic intramural hematoma (IMH) is still controversial. Previous reports on the prognosis of acute aortic dissection (AAD) have investigated the survival cases upon arrival. The clinical courses of AAD during hyperacute phase before arrival to the hospital have yet to be clarified. The aim of this study is to elucidate the pathophysiology of AAD by investigating the prevalence of IMH and classic dissection with pseudo-lumen (PSL) in patients with AAD who developed cardiopulmonary arrest on arrival (CPAOA). Among patients who were carried to our hospital in CPAOA, the prevalence of IMH and PSL in AAD with massive pericardial effusion was evaluated, as well as among AAD patients presenting with cardiac tamponade who were alive upon arrival during the same period. Among consecutive 1063 patients of CPAOA after excluding CPAOA due to injury or suicide, 152 patients underwent echocardiography due to cardiac enlargement observed in chest X-ray. Among them, 40 patients were presented with a significant pericardial effusion. Of these, 29 patients underwent CT study, while the remaining 11 patients did not undergo CT study with various reasons. Of the 29 patients, 26 patients were diagnosed of Stanford type A AAD. Of them, 16 patients (62%) were diagnosed of IMH by a typical ring-shaped high-density lesion at the aortic wall. The remaining 10 patients were diagnosed of PSL by a flap-shaped lesion in the aorta. Among consecutive 134 living patients with a diagnosis of AAD during the same period, 53 patients were diagnosed of type A, of whom 25 patients (47%) were presented with IMH and 28 (53%) were with PSL. The frequency of cardiac tamponade was slightly higher in IMH than in PSL (13/25:52% vs. 8/28:28%, p=0.081). The prevalence of IMH in these 21 patients with cardiac tamponade was as same as that in patients with CPAOA-AAD (13/21:62% vs. 16/26:62%). The prevalence of IMH in CPAOA with massive pericardial effusion was more than half of AAD, suggesting the very early prognosis of type A IMH is worse than expected and the frequency of type A IMH is higher than that in the previous reports.