Prevalence and Prognostic Value of Concealed Structural Abnormalities in Patients with Apparently Idiopathic Ventricular Arrhythmias of Left Versus Right Ventricular Origin: A Magnetic Resonance Imaging Study
Background—Routine diagnostic work-up occasionally does not identify any abnormality among patients with monomorphic ventricular arrhythmias of left ventricular origin (VAs-LV). Aim of the present study was to investigate the value of cardiac magnetic resonance imaging (cMRI) for the diagnostic work-up and prognostication of these patients.
Methods and Results—46 consecutive patients (65% males, mean age 44±15 years) with monomorphic VAs-LV and negative routine diagnostic work-up were included. 74 consecutive patients (60% males, mean age 40±17 years) with apparently idiopathic monomorphic VAs of right ventricular origin (VAs-RV) served as control group. Both groups underwent comprehensive cMRI study and were followed-up for a median of 14 months (25th-75th percentiles 7-37 months). The outcome event was an arrhythmic composite end-point of sudden cardiac death (SCD) or nonfatal episode of ventricular fibrillation or sustained ventricular tachycardia requiring external cardioversion or appropriate implantable cardioverter defibrillator therapy. The 2 groups of patients did not differ in age (p=0.14) and gender (p=0.57). No significant difference was observed between patients with VAs-LV and VAs-RV regarding biventricular volumes and systolic function. Cardiac MRI demonstrated myocardial structural abnormalities in 19 (41%) patients with VAs-LV vs. 4 (5%) patients with VAs-RV (p<0.001). The outcome event occurred in 9 patients; myocardial structural abnormalities on cMRI were significantly related to the outcome event (HR 41.6, 95%CI 5.2-225.0; p<0.001).
Conclusions—Myocardial structural changes are detected by cMRI in a non-negligible proportion of patients with apparently idiopathic monomorphic VAs-LV and are associated with worse outcome.
- left ventricle
- arrhythmogenic right ventricular cardiomyopathy
- myocardial fibrosis
- ventricular arrhythmia
- cardiac magnetic resonance imaging
- Received March 19, 2013.
- Revision received March 25, 2014.
- Accepted March 28, 2014.