Fibrotic Changes in the Myocardium as an Independent Predictor of Rhythm Disturbance in Patients with Hypertrophic Cardiomyopathy

Abstract

The aim: to show the possibilities of the method of magnetic resonance imaging (MRI) in the detection and characterization of hypertrophic cardiomyopathy (HCM). Identify the relationship between the presence of foci of fibrosis in the myocardium of the left ventricle (LV) and the occurrence of arrhythmia.Materials and methods.The study involved 31 patients with HCM and obstruction of the LV outflow tract, who subsequently underwent Morrose's myoseptectomy. In order to detect abnormalities of rhythm, all patients underwent daily Holter monitoring. The presence and nature of the accumulation of contrast medium was assessed by the MRI method in the early and delayed phases of contrasting.Results.The use of MRI with contrast enhancement made it possible to identify areas of delayed contrast in the hypertrophied walls of the LV - fibrotic changes in the myocardium. The centers of fibrosis were revealed in 14 (45.2%) patients. In 5 patients (16.1%), there were no cardiac rhythm disturbances in the presence of changes in the myocardium. Multivariate regression analysis of risk factors showed the relationship between the presence of foci of fibrosis in the myocardium of the LV and the occurrence of arrhythmia (p = 0.021). The presence of violation zones of local contractility (p = 0.327) and the thickness of the hypertrophic wall (p = 0.146) have no significant effect on cardiac rhythm disturbance.Conclusions.The presence of foci of delayed contrast (fibrosis) in the wall of the left ventricle, detected by MRI, increases the chance of arrhythmia in patients with HCM in 12.9 times. MRI with contrast enhancement should be included in the algorithm for diagnosis of HCM, including for evaluating the onset of structural changes in the myocardium.