Predictors of left ventricular scar at cardiac magnetic resonance in athletes with apparently idiopathic ventricular arrhythmias

Abstract

Abstract Introduction In athletes with ventricular arrhythmias (VA) and otherwise unremarkable clinical findings, cardiac magnetic resonance (CMR) may reveal concealed pathological substrates. The aim of this multicentre study was to evaluate which VA characteristics were associated with CMR abnormalities. Methods We enrolled a consecutive series of 251 competitive athletes (74% males, mean age 28.5±14.5 years) who underwent CMR for evaluation of VA. We included athletes with >100 premature ventricular beats (PVBs)/24-hour or ≥1 repetitive VA (couplets, triplets or non-sustained ventricular tachycardia) on 12-lead 24-hour ambulatory ECG monitoring and negative family history, electrocardiogram and echocardiogram. Features of VA that were evaluated included number, morphology, repetitivity and response to exercise testing. Results Left-ventricular late gadolinium-enhancement (LGE) was documented in 28 (11%) athletes, mostly (N=25) with a subepicardial/midmyocardial (non-ischemic) distribution. On 24-hour ECG monitoring, PVBs with a right-bundle-branch-block and intermediate/superior axis configuration or multiple morphologies were documented in 24/28 (86%) athletes with versus 55/223 (25%) without LGE (p<0.001). More than 2000 PVBs were recorded in 6 (21%) athletes with versus 127 (57%) without positive CMR (p<0.001). At exercise testing, repetitive VA occurred at high work-load in 12 (43%) athletes with versus 26 (12%) without LGE (p<0.001). At multivariable analysis, all three VA features independently correlated with CMR abnormalities. Conclusions In athletes with apparently idiopathic VA, simple characteristics such as number and morphology of PVBs on 12-lead 24-hour ambulatory ECG monitoring and response to exercise testing predicted the presence of concealed myocardial abnormalities on CMR. These findings may help cost-effective CMR prescription. Flow chart Funding Acknowledgement Type of funding source: None