EFFECTS OF ALTITUDE UPON CARDIOVASCULAR-DISEASES

Physicians should be aware of sea level cardiovascular problems that may be aggravated by exposure to high altitude. Increasing numbers of middle-aged and elderly individuals are visiting high altitude areas to ski, trek or attend conferences. Many Elder Hostel programs are held in mountain environments. A recent survey of 1909 adult visitors to Keystone, Colorado [altitude 9300 ft (2837 m)] revealed that 48% were 40-60 years of age and 15% were over 60. Sixty-six percent were males [1]. Approximately 10% of trekkers in Nepal were 50 years of age or older [2]. The prevalence of many cardiac conditions rises rapidly after age 50. For example, the mean age of entry of 2234 men into three large randomized studies of surgery in coronary artery disease was 50-51 years [3]. This presentation will review altitude-induced changes that affect the circulatory system and examine three cardiovascular conditions that are adversely affected by altitude. These are coronary artery disease, systemic hypertension, and pulmonary hypertension. High altitude, for the purpose of this presentation, is defined as elevation above 8000 ft (2440 m), since altitude illness and altitude aggravation of sea level conditions are rare below this altitude.