Diagnostic capabilities of electrocardiography systolic heart failure

Abstract

The contractility of the myocardium is determined by the strength and speed of contraction of the ventricles. It can be estimated from the Q-T interval of the electrocardiogram, which is an electrical systole of the ventricles. Set the change in ventricular systole by the deviation of the actual interval of Q-T from the corrected one. Elongation of ventricular systole indicates a violation of myocardial contractility, which causes the development of systolic heart failure. When comparing this indicator with the results of echocardiography, reflecting the contractility of the left ventricle, their direct dependence was established. The greater the degree of breach of myocardial contractility, the higher the percentage of the deviation of the actual Q-T interval from the corrected one. The maximum figures were recorded in patients with a global contractility disorder. This indicator can be used to detect both acute and chronic systolic insufficiency. It was established that in all patients with heart failure there was an increase in the Q-T interval. The magnitude of it depended on the degree of manifestation of heart failure. The increase in the percentage deviation of the actual value from the control occurred in patients with heart failure from I functional class to IV. Only in 1/5 of patients with heart failure of I functional class, the actual value did not differ from the control one, but under physical load, it increased significantly, which indicates the presence of latent systolic insufficiency. It is also found in patients with heart failure with a preserved ejection fraction, the development of which is associated with diastolic dysfunction. Electrocardiography can be used as a method of diagnosing systolic heart failure, which is highly informative and specific.