Type A aortic dissection manifesting as acute myocardial infarction: still a lesson to learn.

OBJECTIVE

Type A aortic dissection manifesting as acute myocardial infarction (AMI) is relatively rare but could be catastrophic if the management is not appropriate. This study investigated the incidence, outcome and potential diagnostic pitfalls of patients with such manifestations, and proposes a useful diagnostic paradigm.

METHODS AND

RESULTS

From 1 January 1995 to 31 July 2006, 531 patients admitted to our hospital with the initial or later diagnosis of acute aortic dissection were reviewed. Two hundred and thirty-nine patients were diagnosed as Stanford type A aortic dissection with a mortality rate of 17% (41/239). Eleven (5%) of the 239 patients had initial presentation of AMI (chest pain and elevation of cardiac enzymes, with or without ST-segment elevation) and a high mortality rate of 36% (4/11). All six patients with ST-segment elevation underwent coronary angiography without awareness of type A aortic dissection; three patients were detected to have eccentric aortic regurgitation by transthoracic echocardiography (TTE) before angiography but type A aortic dissection was neglected at that time. Three of the five patients without ST-segment elevation also had eccentric aortic regurgitation by TTE before the confirmative diagnosis was made; prompt suspicion of type A aortic dissection was assisted with an elevation of D-dimer value in one of these three patients. The presence of eccentric aortic regurgitation by TTE, and the increased D-dimer value provided hints of the coexistence of AMI and type A aortic dissection.

CONCLUSIONS

Type A aortic dissection manifesting as AMI is a catastrophe in disguise. Prompt checks of TTE and the D-dimer value would bring the hidden diagnosis of acute aortic dissection more to the forefront.