Using of magnetic resonance imaging for diagnosis of noncoronary pathology in children and adolescents with premature ventricular contractions
The purpose of the article was to assess by MRI cardiac output in young patients with ventricular arrhythmias and to identify with the use of contrast enhancement possible changes of the myocardium that may cause these ventricular arrhythmias. Material and methods. Survey data of 11 patients – 7 males and 4 females (mean age 15,6 ± 3,4 years) – with ventricular arrhythmias were analyzed. MR-study was conducted on a CT-scanner with a field strength of 1.5 T and with the use of a special package for scanning. The data were processed on workstations using specialized programs for cardiac MR-images. We evaluated the ejection fraction (EF) of both ventricles, enddiastolic volume (EDV), the size of outlet sections of both ventricles, pathological changes in the myocardium (localization and spread using a segmental model of the heart) before and after intravenous administration of contrast medium (HF ) containing gadolinium dose 0.15-0.2 mg / kg. Results. According to previous studies, patients were divided into 2 groups based on the detected arrhythmia localization: 7 children with right ventricular arrhythmia localization and 4 with left ventricular. Surface mapping (PC) was performed in 8 patients, and topical diagnosis of arrhythmia localization coincided with the localization of the accumulation of MR-contrast agent in 75% of cases. Expansion of outlet sections of right ventricle without signs of left ventricular enlargement (1.40 / 1) was significantly higher (p <0.05) children in Group 1. Ejection fraction of both ventricles in children of Group 2 was below the normal range (mean RV EF 42%, LV ejection fraction 54%), and RV ejection fraction was significantly lower (p <0.05) and segment by segment incidence of edema significantly higher (p <0.05) compared with data from a Group 1. EDV, LVEF, number of post-inflammatory and non-inflammatory changes did not differ significantly (p> 0.05) in both groups. However, the thickness of epicardial fat (2 ± 1 mm) on the localization of the LV in children with postinflammatory change was significantly higher (p <0.05) in both groups. Conclusion. In all cases, we were able to obtain important diagnostic MR-images of the heart with IV-contrast, to show a high accuracy of MRI in the detection of pathological changes in the diagnosis of myocardial contractility disorders not only of the left, but of the right ventricle. Violations of intracardiac hemodynamics were more pronounced in the case of left ventricular localization of arrhythmias than the right one.