Table II summarizes the key studies and findings of altitude effect on arrhythmias.
Heightened sympathetic activity associated with rapid ascent to altitude and subsequent exercise may increase the frequency and duration of supraventricular and ventricular arrhythmias in patients with underlying heart disease as well as healthy volunteers.[54,55] Patients with atrial fibrillation or flutter have been noted to have higher ventricular response rates after rapid ascent to altitude. Theoretically, high sympathetic and/or reduced parasympathetic tone may increase risk for ventricular arrhythmias and sudden death in patients 6 to 12 months after a myocardial infarction when exercising in a hypoxic and often cold environment based on heart rate variability analysis. However, this has not translated into a significant demonstrable increase in ventricular tachycardia at altitude.[6,36]
In summary, rapid ascent to altitude may result in faster heart rates in patients with atrial fibrillation or atrial flutter, and consideration to increasing doses of rate limiting medications (eg, β-blockers) may be regarded. Although there is a theoretical risk of increased ventricular arrhythmias based on increased sympathetic tone, this does not appear to be clinically relevant.
Am Heart J © 2010
Cite this: Altitude and the Heart: Is Going High Safe for Your Cardiac Patient? - Medscape - Jan 01, 2010.