A Practical Approach to Syncope

Abstract

P.S. is a 68-year-old retired sales representative who presented with two episodes of syncope which have occurred over the previous three months. The first syncopal episode occurred following dinner while he was helping his wife clear the table. P.S. felt light-headed then suddenly lost consciousness, fell and suffered facial lacerations. The patient’s wife stated that while he was unconscious he appeared blue and was motionless. The patient remained unconscious for approximately 1–2 minutes, then spontaneously regained consciousness with a clear sensorium. He underwent evaluation by his personal physician, including a 12 lead ECG, which revealed first degree atrioventricular block, heart rate of 60, and Q waves in leads V-2 through V-5 consistent with an old anterior wall myocardial infarction. The chest x-ray was unremarkable. Serum electrolyte screen including potassium, magnesium and calcium was within normal limits. A 24-hour ambulatory ECG revealed frequent premature ventricular beats and a four-beat run of wide complex tachycardia. A head CT scan and EEG were within normal limits. A two-dimensional echocardiogram revealed normal heart valves with depressed left ventricular function. An exercise tolerance test revealed that the patient exercised for 10 minutes without chest pain or ischemic ST segment changes. Cardiac catheterization demonstrated a left ventricular ejection fraction of 45 percent with anterolateral wall akinesis and total occlusion of the left anterior descending coronary artery. Because no definitive source for syncope could be found, the patient was left untreated. P.S. suffered a second syncopal episode while walking the family dog. This episode was similar to his first episode.