O papel da ressonância magnética cardíaca na investigação de arritmias ventriculares

Abstract

Background: Ventricular arrhythmias are common findings in clinical practice and may occur in structurally normal heart or in the presence of structural heart disease. Cardiac magnetic resonance (CMR) may be useful in detecting mild heart diseases, undiagnosed by other methods. Objective: To demonstrate the importance of CMR in the diagnosis of ventricular arrhythmias etiology. Methods: This is a cross-sectional observational study that included all consecutive patients referred for CMR presenting ventricular arrhythmia of unknown etiology, from December 2008 to July 2012. Results: We evaluated 288 patients, with a mean age of 48.9 ± 18.6 years. All patients underwent cine-MRI, black-blood and delayed enhancement and 46.8% of the exams were done with pharmacological stress. There were no morphological or functional abnormalities in 194 patients (67.4%). The most prevalent diagnoses with CMR were previous myocarditis and arrhythmogenic right ventricular dysplasia. Other important findings were: myocardial ischemia, noncompacted myocardium, aortic valvular disease and hypertrophic cardiomyopathy. Conclusion: CMR detected anatomical and/or functional changes in 32.6% of the cases, being helpful to define a probably etiology of arrhythmic focus. Future follow-up studies should be done to clarify the actual role of the clinical abnormalities found by this methodology.