Low risk of myocardial ischemia in the elderly visiting moderate altitude

Abstract

Objective: Ascent to high altitude may be associated with changes in heart rate and systolic blood pressure, resulting in greater cardiac work. In elderly individuals with coronary artery disease, these changes may lead to myocardial ischemia. We studied an elderly population to assess the incidence of myocardial ischemia and the effect on the electrocardiogram (ECG) during a visit to moderate altitude.

Design: Inception cohort study.

Setting: Vail, Colorado (2500 m).

Participants: Members and spouses of the Tenth Mountain Division reunion.

Interventions: Resting 12-lead ECGs and blood pressures were obtained daily for 4 days.

Results: Ninety-seven subjects participated (77 men and 20 women) with a mean age of 69.8 ± 4.4 years. Twenty-one percent of our subjects had some manifestation of coronary artery disease. On arrival, 59 (61%) of the ECGs were normal, 1 (1%) borderline, and 37 (38%) abnormal. No new ST-T-wave abnormalities clearly indicative of myocardial ischemia during the altitude stay were found. When compared to baseline ECGs recorded previously in 56 of our subjects, 8 (14%) had P-wave vector changes probably related to pulmonary hypertension. Cardiac work as estimated by the heart rate-blood pressure double product was increased by 13% at rest.

Conclusions: Despite an increase in cardiac work, no new ST-T-wave abnormalities clearly indicative of myocardial ischemia were present on arrival or during the next 4 days at altitude. Despite a high prevalence of ECG abnormalities and probable coronary artery disease in these elderly subjects, ascent to moderate altitude did not appear to precipitate myocardial ischemia in subjects with asymptomatic coronary artery disease (New York Heart Association Class I).