POLYMORPHIC VENTRICULAR EXTRASYSTOLIA IN PATIENTS WITHOUT STRUCTURAL CHANGES IN THE HEART: CLINICAL AND PROGNOSTIC SIGNIFICANCE AND ASSESSMENT OF THE EFFECTIVENESS OF THE THERAPY (CLINICAL AND EXPERIMENTAL STUDY)

Highlights In patients without structural changes in the heart, predictors of arrhythmogenic cardiomyopathy were recorded significantly more often when polymorphic left ventricular extrasystole was detected. When predominantly polymorphic right ventricular extrasystoles were detected in patients without structural changes in the heart, the pathology of the cardiovascular system was not recorded, but with polymorphic left ventricular extrasystole, the development of pathology of the cardiovascular system, such as various clinical forms of coronary heart disease, hypertension, and mitral valve prolapse, was observed. Summary Aim. To individualize the choice of drug therapy for polymorphic ventricular extrasystole (PVC) in patients without structural heart changes (PWSHC) by assessing predictors of arrhythmogenic cardiomyopathy (PAC) and the clinical and prognostic value of its course. Methods. Experimental study. Modeling of PVC was carried out in animals using the mechanism of delayed postdepolarization (LDP) using barium chloride, strophanthin and adrenaline. In electrocardiography (ECG), in addition to generally accepted parameters, PAC such as the pre-ectopic interval, its variability, the maximum index of internal deviation of the PVC (MIVDpvc), the duration of the QRS complex PVC (QRSpvc), QRS sinus rhythm (QRSsr), their ratio (QRSpvc/QRSsr) were analyzed. Clinical study. There were 272 PWSHC aged from 16 to 34 years with PVC classes IV–V (B.Rayn, 1984). The ECG determined the same parameters as for experimental arrhythmias. The duration of observation of patients was up to 10 years. The end point of observation was the detection or absence of pathology of the cardiovascular system. Results. Experimental study. In all animals, when modeling ventricular arrhythmias using the LDP mechanism, PVC was recorded. PAC were identified when modeling arrhythmia using strophanthin and adrenaline. Clinical study. In PWSHC PVC from the right ventricle without PAC, it was highly correlated with barium chloride-induced ventricular ectopy (r = 0.94). In 160 (58.82%) PWSHC with right ventricular premature complexes, the pathology of the cardiovascular system was not registered, and in 112 (41.18%) – with left ventricular ectopy with detected PAC, an average of 5.5 ± 0.14 years after inclusion in the study was observed development of arterial hypertension, mitral valve prolapses. In all patients, antiarrhythmic drugs of class II and, to a lesser extent, class III were the most effective for stopping polymorphic PVC. Conclusion. In PWSHC, the development of diseases of the cardiovascular system, such as arterial hypertension, mitral valve prolapse, was observed when polymorphic left ventricular ventricular ectopy was detected in combination with PАC.