A 64-year-old woman was admitted to our hospital with sudden chest and back pain. Computed tomography showed acute type A aortic dissection complicated with malperfusion of the left main coronary artery (LMT). Immediately after the CT, the patient went into sudden shock. Electrocardiogram showed ventricular tachycardia and ventricular fibrillation. Percutaneous cardio-pulmonary support was administered and coronary arteriogram (CAG) was performed. CAG revealed LMT stenosis and intravascular ultrasound showed mobile intimal flap at the LMT. Percutaneous coronary intervention of the LMT was performed. The patient recovered from shock and was treated with ascending aorta replacement with CABG. The patient was discharged from the hospital without any major complication.