[Incidence of heart rhythm and conduction disorders in chronic cor pulmonale among alpine inhabitants].

Electro- and echocardiographic studies were carried out in 708 male mountain-dwellers (at altitudes of 2800--4200 m) and 1047 male dwellers of lower altitudes (700--800 m), aged 30 to 59 years. One-hour ECG monitoring was conducted in 90 mountaineers. The latter population showed a high incidence of echocardiographically-confirmed signs of right-ventricular hypertrophy (RVH) of varying degrees. They also showed relatively high rates of heart rhythm and conductivity disorders (13.7% vs. 3.18% of low-altitude dwellers; p less than 0.001). As RVH gained in markedness, and as the recording time grew longer, the frequency of detected cardiac arrhythmias increased dramatically. RVH, arterial hypoxemia and pulmonary arterial hypertension are risk factors contributing to cardiac arrhythmias.