CMR for Identifying the Substrate of Ventricular Arrhythmia in Patients with Q1 Normal Echocardiography

<p>OBJECTIVES This study sought to determine whether cardiac magnetic resonance (CMR) may identify structural heart<br> disease (SHD) in patients with ventricular arrhythmia who had echocardiography ruled out pathological findings.<br> BACKGROUND Approximately one-half of sudden cardiac deaths are attributable to malignant VA. Echocardiography is<br> commonly used to identify SHD that is the most frequent substrate of VA.<br> Q6 METHODS A single-center prospective study was conducted in consecutive patients with significant VA, categorized as<br> &gt;1,000 but &lt;10,000 ventricular ectopic beats [VEB]s/24 h; $10,000 VEBs/24 h; nonsustained ventricular tachycardia,<br> sustained ventricular tachycardia (SVT), or a history of resuscitated cardiac arrest, and no pathological findings at<br> echocardiography, requiring a clinically indicated CMR. Primary endpoint was CMR detection of SHD. Secondary endpoints<br> were a composite of CMR detection of SHD and abnormal findings not specific for a definite SHD diagnosis.<br> RESULTS A total of 946 patients were enrolled (mean 41 16 years of age; 64% men). CMR studies were used to<br> diagnose SHD in 241 patients (25.5%) and abnormal findings not specific for a definite SHD diagnosis in 187 patients<br> (19.7%). Myocarditis (n &frac14; 91) was the more frequent disease, followed by arrhythmogenic cardiomyopathy (n &frac14; 55),<br> dilated cardiomyopathy (n &frac14; 39), ischemic heart disease (n &frac14; 22), hypertrophic cardiomyopathy (n &frac14; 13), congenital<br> cardiac disease (n &frac14; 10), left ventricle noncompaction (n &frac14; 5), and pericarditis (n &frac14; 5). The strongest univariate and<br> multivariate predictors of SHD on CMR images were chest pain (odds ratios [OR]: 2.52 and 2.38, respectively) and SVT<br> (ORs: 2.67 and 2.23, respectively).<br> CONCLUSIONS SHD was able to be identified on CMR imaging in a sizable number of patients with significant VA and<br> completely normal echocardiography. Chest pain and SVT were the strongest predictors of positive CMR imaging<br> results.&nbsp;</p>