[Acute thoracic aortic dissection with occlusion of the left coronary artery]

Aortic dissection is the most common fatal condition that involves the aorta. Occasionally, symptoms mimic acute myocardial infarction leading to thrombolytic treatment. Accurate diagnosis in patients with chest pain is therefore essential. We describe a case of acute aortic dissection which resulted in myocardial infarction due to obstruction of the left coronary ostium. A 65-year-old female patient with no previous cardiac history was admitted to a local hospital because of severe chest pain of acute onset. Physical examination was normal except for a low blood pressure (90/50 mm Hg), heart rate 45 beats/min and parasthesia in both hands. The ECG showed sinus bradycardia with negative T-wave in VI and with 1 mm ST-segment elevation in V3. A chest X-ray was normal. Five hours later, the patient experienced once more severe chest pain followed by non-sustained polymorphic ventricular tachycardia (Figure 1). Another ECG showed bifascicular bundle branch block (right bundle branch block and left anterior fascicular block). The ECG was interpreted as showing acute myocardial infarction and treatment with intravenous streptokinase started. Since the patient remained severely hypotensive despite infusion of dobutamine, she was intubated, ventilated and transferred to our hospital. Cardiac catheterization showed acute dissection of the ascending aorta with an aortic intimal flap and an occlusion of the left coronary artery (Figures 2a and b). During catheterization, she suffered a cardiac arrest from which she could not be resuscitated. A postmortem examination confirmed the acute aortic dissection which reached to the ostium of the left coronary artery (Figures 3a and b, 4a and b) and an anterior myocardial infarction probably due to intermitted diastolic obstruction of the ostium of the left coronary artery by an aortic intimal flap.