[Interpretation of the ECG changes using the Minnesota code in the presence of right-ventricular (high-altitude) cardiac hypertrophy]

Abstract

The research showed a high incidence of electrocardiographic signs of hypertrophy of the right ventricle of the heart under high-altitude conditions. Code 2-3 was found in 49.2% of highlanders examined, code 2-4 in 1.5%, code 3-2 in 17.0%, and code 9-4-2 in 54.4%. Some cases of hypertrophy of the right ventricle of the heart (code 3-2, approximately 4-5%) are attended by disturbances in the repolarization processes in the right chest electrocardiographic leads (code 5-1 or 5-2). According to the interpretations of the Minnesota code, these shifts should be considered ischemic. But information yielded by the Rouz questionnaire, the results of clinical examination, and tests with maximum physical load in 8 persons who had such shifts on the ECG did not confirm the presence of symptoms of ischemic heart disease. That is why changes in T wave detected in highland aborigenes with marked right-ventricular hypertrophy but no clinical symptoms of ischemic heart disease should be accepted as evidence of ischemia. Otherwise, if the disturbances in the repolarization processes are interpreted as signs of myocardial ischemia, the prevalence of ischemic heart disease among the population of the highlands may be overestimated. The introductin of restriction in relation to code 3-2 when it is combined with code 5-1 or 5-2 will make it possible to study more exactly the true prevalence of ischemic heart disease in the presence of hypertrophy of the right ventricle of the heart.