Left ventricular dysfunction in coronary heart disease at high altitude

摘要

Official guidelines do not address exposure of patients (pts) with asymptomatic left ventricular dysfunction (LVD) to high altitude (HA). Good tolerance to exercise at 2500 m was observed in coronary (CAD) pts with LVD without residual ischemia, but direct measures of LV function at altitude are not reported in such pts. Fifteen pts (14M, IF) aged 45-70 (mean 58+8 yrs) with CAD, LVD (LVEF 32+7%), all in I NYHA class, without residual ischemia (maximal symptom-limited bicycle stress test, echo-dobutamine stress test), all used to mountaineering or hiking before CAD, were studied after a cardiac rehabilitation program. They underwent a first bidimensional echocardiography with colour-Doppler at low altitude (320m, LA) and a second exam, within one month, at HA (2874m) reached by cablecar and 30 min walking. All pts were asymptomatic at HA; no pts complained of symptoms nor had signs of acute mountain sickness or heart failure. Mean LVEF did not change from LA to HA: 32+-7% vs. 33+-8% respectively, but individual changes ranged from a 9% decrease to a 7% increase; 4 pts had a >5% decrease, 5 pts had a >5% increase. Pts with HA deterioration in LV function showed lower E/A and prolonged deceleration time of early filling at LA Doppler mitral flow velocity profile. LVD does not seem an absolute contraindication to HA (<3000 m), but a more appropriate functional evaluation of these pts needs to be established.