High Altitude and Intracardiac Devices (Pacemaker and Intracardiac Defibrillator and Cardiac Resynchronisation Therapy)

Cardiovascular system responds to high altitude short after exposure. Hypoxia induces increase in heart rate, myocardial contractility, and cardiac output. This may have clinical implications in patients with underlying heart disease such as coronary artery disease, heart failure and rhythm disorders. Past studies have showed that patients may experience altitude-induced arrhythmias. However, there are conflicting data for patients with cardiac devices such as permanent pacemaker, intracardiac defibrillators (ICDs) and cardiac resynchronisation therapies (CRTs). Limited studies demonstrate that patients with pacemakers can be safely exposed to high altitudes with no impact on ventricular stimulation thresholds, however effects of altitude on ICDs or CRTs are still unknown at the present time requiring further research.