[Diagnostic characteristics of cardiac insufficiency under mountain conditions]

In patients with mitral lesions and prevalence of stenosis and insufficient circulation of the I, II A and B stages clinical and functional indicators of the cardiac work were studied at three different altitudes, viz. with a low-mountain relief (760 m), middle-mountain relief (1650-2020 m) and in highland (3600-4200 m). In highland decompensated mitral incompetence was found to be characterized by a much higher incidence of such manifestations of the disease as vertigo, syncopal attacks, fits of distressed respiration, epigastral pulsation, positive venous pulse, a significant expansion of the heart to the right, accentuation and splitting of the II tone on the pulmonary artery, overloading of the right ventricle and atrium (according to ECG findings), the absence of peripheral edematization and fibrillation arrythmia, the presence of arterial and venous hypotension, highly intensive hyperventilation, a drop of PAO2 and PACO2. In patients-residents of low- and middle-mountain regions the severity of clinical and hemodynamic disorders depended on the stage of cardiac insufficiency, whereby in residents of the second region the disclosed deviations on the level of circulation proved more marked. It is shown that the correlation links between individual physiological variables become greatly disrupted parallel with progressively increasing severity of cardiac incompetence. In conditions prevailing in the middle and, especially, high altitude areas there are evident links between individual functional indicators which are absent in low-mountain areas. The above data bear evidence not only to the fact that with progressive severity of cardiac insufficiency the disrupted regulation of the circulation system becomes still more aggravated, but also to the presence of other compensatory mechanisms that are operative in mountain areas.