The Safety of Trekking at High Altitude After Coronary Bypass Surgery

To the Editor.— In a recent QUESTIONS AND ANSWERS section,1it was asked if a 51-year-old patient with an excellent result from coronary bypass surgery should go on a trek to Nepal up to altitudes of 5760 m (19 008 ft). An exercise treadmill test and a thallium scan had shown "good results" and the patient had been doing long-distance jogging. Two consultants stated that "some risk" would be entailed owing to the low arterial oxygen partial pressure at that altitude and the patient was advised not to go, since "it would be better to err on the side of being safe rather than sorry." I have reservations regarding this advice. If this policy is applied to the many thousands of active individuals who have had coronary bypass surgery, it will result in needless fear and concern about the effect of altitude on the heart and continue to promote