Diagnostic Value of Cardiac Magnetic Resonance in Patients with Frequent Ventricular Arrhythmia and Normal Doppler Echocardiography.

IntroductionFrequent ventricular arrhythmia can be a primary electrical disturbance or may beassociated to cardiomyopathy. The prognostic and therapeutic impact depends onthe presence of structural heart disease. Transthoracic Doppler echocardiographyhas been the most important complementary study to evaluate the presence of cardiacstructural abnormalities.ObjectivesThe aims of this study were to determine the ability of cardiac magnetic resonanceimaging to detect structural heart disease in patients with normal Doppler echocardiogramand to assess the incidence of adverse cardiovascular events during followup.MethodsThe study included 66 consecutive patients with frequent ventricular arrhythmiadefined as > 5000 ventricular extrasystoles in 24-hour Holter monitoring, ventriculartachycardia or resuscitated cardiac respiratory arrest with normal Dopplerechocardiogram. All patients underwent cardiac magnetic resonance imaging to assesscardiomyopathies.ResultsFifty-seven percent of patients had structural heart disease. The most prevalentdiagnosed pathologies were myocarditis sequelae, non-compacted myocardium andsubendocardial infarction scar. At mean follow-up of 24 ± 22 months, the incidenceof adverse cardiovascular events was 6.06 %. The number of ventricular extrasystoleswas higher in patients with abnormal cardiac magnetic resonance.DiscussionThis work demonstrates that in patients with frequent ventricular arrhythmia andnormal Doppler echocardiogram, gadolinium cardiac magnetic resonance imagingcan detect structural heart disease in more than half of the cases. Patients with frequentventricular arrhythmia during Holter monitoring, normal Doppler echocardiogramand mild alterations in the magnetic resonance present low risk of cardiovascularevents.