Diagnosing acute Stanford type A aortic dissection with the uncommon involvement of the left main coronary artery(LMCA) remains challenging for the emergency physician because it can resemble acute myocardial infarction with cardiogenic shock. The following case report illustrate this infrequent but critical situation. A 52-year-old woman with a history of hypertension awakened with acute retrosternal chest pain accompanied by nausea and vomiting. She was referred to our hospital for primary coronary intervention because of acute myocardial infarction with cardiogenic shock. Coronary angiography indeed revealed LMCA occlusion. Subsequently successful percutaneous coronary intervention with stent implantation was performed, followed by immediate clinical improvement of the patient. Soon after admission at the coronary care unit, severe chest pain, hypotension, and electrocardiographic signs of diffuse myocardial ischemia relapsed. Control coronary angiography,however, showed no in-stent thrombosis. Review of clinical examination revealed an aortic regurgitation murmur. Because of this dynamic pattern of (1) signs of acute myocardial ischemia, (2) relapse of hemodynamic collapse, and (3) unaltered control coronary angiography together with the confirmed aortic regurgitation at transthoracic echocardiography, the patient was suspected of having aortic dissection. Transesophageal echocardiography revealed Stanford type A aortic dissection with severe eccentric aortic regurgitation and no pericardial effusion. Emergent valve-sparing aortic replacement was performed. The patient recovered completely. In this case, the lifesaving element was primary coronary intervention with stenting of the LMCA preventing extensive myocardial damage followed by a surgical correction of the aorta.