RV is doing well at high altitudes!--Always?

Altitude exposure has long been recognized as a cardiac stress. Early accounts of alpine climbs mention a diagnosis of “cardiac fatigue” based on tachycardia, palpitations, shortness of breath, and chest percussion (fonendoscopy) of enlarged hearts (1). Heart failure syndromes have been reported at high altitudes under various names including brisket disease in cattle brought to high-altitude pastures in Utah and Colorado (2), chronic mountain sickness (CMS) or Monge’s disease in the inhabitants of the South American altiplano (3), less frequently in Han Chinese immigrants to Tibet (4), subacute mountain sickness corresponding to a form of rapidly evolving right ventricular failure observed in Indian soldiers posted at the high-altitude borders in China (5), in Han Chinese infants brought to reside in Tibet (6), and occasional echocardiographic highaltitude right heart failure in previously healthy travelers (7). When diagnosed at high altitudes, heart failure is almost always predominantly right sided. This is explained by hypoxic pulmonary vasoconstriction and remodeling as a cause of increased right ventricular (RV) afterload and possibly a contribution of negative inotropic effects of ambient hypobaric hypoxia (8).