Cardiac Arrhythmias at Extreme Altitude

Background: Exposure to high altitudes has been associated with an increased risk of cardiac arrhythmias in healthy subjects and an increased risk of sudden cardiac death.Aim: The aim of the present study is to evaluate the risk and the incidence of cardiac arrhythmias at extreme altitude.Methods: This is a prospective cohort study of healthy volunteers determined to climb Mount Everest. Subjects will be evaluated for eligibility by electrocardiography and echocardiography. All study participants will undergo ambulatory rhythm monitoring in their home environment within 12 weeks of the climb. Subsequently, ambulatory rhythm monitoring will be repeated during the ascent from basecamp to the summit of Mount Everest. The primary endpoint will be the composite of supraventricular and ventricular tachyarrhythmias, and bradyarrhythmias.

Inclusion Criteria:Age ≥18 yearsNormal electrocardiogramNormal echocardiographyWritten informed consentExclusion Criteria:Known cardiac arrhythmiaEvidence of AV-block, left bundle branch block, or repolarization disorders on electrocardiogramEvidence of structural heart disease (valve disease more than mild) or compromised left ventricular ejection fraction as assessed by echocardiographySymptoms or history of skin cancer, rash, skin disease, keloid or injuryCardiac pacemakers, cardiac defibrillators, implantable electrical devicesPregnancy, breastfeeding