Abstract
A substantial number of men and women over 50 years of age engage in trekking, skiing and mountaineering, in many instances at elevations from 8000 ft (2440 m) to 18000 ft (5490 m). Many of these individuals have known coronary artery disease or, if asymptomatic, may have subclinical coronary disease. Several observations are pertinent: (1) The risk of sudden death or acute infarction during vigorous exercise, such as during symptom limited exercise tests, rehabilitation programs or jogging, is extremely small; (2) In patients with known or suspected coronary disease, exercise testing should be performed to determine risk status before starting a program of vigorous exercise; (3) Low risk patients can be reassured that exercise is not harmful and appropriate medical management can be instituted; (4) High risk patients should be referred for coronary arteriography to establish the appropriate management, i.e., medical, surgical or angioplasty. Exercise testing in asymptomatic patients without risk factors for coronary disease is not usually indicated; and (5) Upon ascent to high altitude, symptoms of coronary disease are usually increased for the first few days after arrival due to increased sympathetic stimulation induced by hypoxemia. There is no evidence that exercise after acclimatization at high altitude is of greater risk to the heart than similar exercise performed at sea level.