Features of structural and electrical remodeling of the heart associated with high risk of life threatening ventricular tachyarrhythmias in patients with ischemic and non-ischemic cardiomyopathies

Objective: to identify the features of myocardial fibrosis and ventricular repolarization disorders associated with malignant ventricular tachyarrhythmias (VT) in patients with ischemic (ICM) and non-ischemic cardiomyopathy (NICM).Material and Methods. Fifty consecutive patients (41 men and 9 women aged 60±13 years; 30 patients with ICM and 20 patients with NICM) underwent contrast magnetic resonance imaging (MRI) of the heart, QT dispersion analysis of 12-lead Holter ECG followed by implantation of cardioverter-defibrillator (ICD) or resynchronizing device with defibrillator (CRTD) to prevent sudden cardiac death.Results. According to data of 32 (28-43)-month follow up, VT paroxysms were registered in 20 of 30 patients (67%) with ICM and in 5 of 20 patients (25%) with NICM on follow-up. Data of successive univariate and ROC analyses of MRI indices differed between patients with and without recurrence of VTs in ICM and NICM patient groups. In ICM patients, VTs were associated with the values of QT (peak) interval dispersion over 80 mc according to data of Holter ECG monitoring and higher gray zone in the left ventricle (≥27%) according to contrast-enhanced MRI. Similar analyses in NICM patients showed that the most valuable diagnostic signs associated with the right ventricular tachycardias were the values of QT (peak) interval dispersion over 90 mc according to data of Holter ECG monitoring and the presence of non-transmural fibrosis of the left ventricle (≥27%) according to contrast-enhanced MRI.Conclusion. The features of structural remodeling of the left ventricle predisposing to VTs significantly differ in patients with ICM and NICM. Nevertheless, the presence of ventricular repolarization disorders, associated with onset of VTs, is universal in patients with ischemic and non-ischemic cardiomyopathies.