High Altitude and Pulmonary Arterial Hypertension

Physiological Response to High Altitude

• The body compensates for high altitudes through increased pulmonary ventilation, increased cardiac output by raising heart rate, changes in vascular tone, and eventually an increase in hemoglobin concentration, as noted by the European Society of Cardiology 1, 2
• Pulmonary vasoconstriction is a direct response to acute hypoxia, cold exposure, and increased ventilation, according to the European Heart Journal 1, 3

Management Recommendations

• The European Society of Cardiology recommends that patients with known pulmonary hypertension consider using supplemental oxygen when exposed to altitudes >1500-2000m 5, 6, 7
• For patients with WHO Group 1 PAH with functional class III-IV symptoms, in-flight oxygen administration should be considered, as well as for those with low oxygen levels, as suggested by the European Society of Cardiology 5, 7

Special Considerations

• Patients with congenital heart disease and concurrent pulmonary hypertension should be particularly careful when going to high altitude, as elevated pulmonary pressure due to pre-existing conditions worsens the effects of high-altitude exposure, according to the European Society of Cardiology 5, 8
• The increase in pulmonary vascular resistance at high altitude can worsen right-to-left shunting in patients with cyanotic heart conditions, as noted by the European Society of Cardiology 5, 8