Ventricular tachyarrhythmias prediction in patients with ischemic cardiomyopathy

Aim . To identify predictors of ventricular tachyarrhythmias (VTA) in patients with ischemic cardiomyopathy. Materials and methods . The study included 40 patients (males - 36, mean age - 63,4 ± 7,8 years) with coronary artery disease (CAD), II-III functional class of chronic heart failure, left ventricle ejection fraction 35% or less, without sustained VTA and cardioverter-defibrillator (CD) implantation indications (primary prevention of the sudden cardiac death). Patients before CD implantation underwent 6-minute walk test, echocardiography, heart rate variability (HRV) analysis and cardiac single-photon emission computed tomography with 123I-meta-iodobenzylguanidine ( 123 I-MIBG). All patients after CD implantation were followed-up during two years and divided into two groups. The 1-st group consisted of patients with VTA events, the 2-nd group - without VTA events. Results . The 1-st group consisted of 36 (90,0%) patients, the 2-nd group - 4 (10,0%) patients. The univariate ROC-analysis showed that the low values of the HRV, reflecting a decrease of the parasympathetic effect on the heart, as well as an increase in indexed left ventricle volumetric and dimensional indicators (end-diastolic and end-systolic indices) and 123 I-MIBG accumulation defect on early and delayed scintigrams, reflecting an increase of the sympathetic effect on the heart leaded to frequent occurrences of the VTA (p=0,0001). The multivariate ROC-analysis demonstrated that only LF (p=0,0136), which associated with sympathoparasympathetic imbalance, leaded to frequent occurrences of the VTA. Also, increase of the VTA predictive ratio, calculated according to this predictive model, more than 0,8936 leaded to frequent occurrences of the VTA (p=0,0001). Conclusion . In patients with ischemic cardiomyopathy, the predominance of sympathetic and a decrease of parasympathetic effects on the heart, assessed by the analysis of heart rate variability, is a predictor of the life-threatening ventricular arrhythmias.