Predictors of Left Ventricular Scar Using Cardiac Magnetic Resonance in Athletes With Apparently Idiopathic Ventricular Arrhythmias

Abstract

Background In athletes with ventricular arrhythmias (VA) and otherwise unremarkable clinical findings, cardiac magnetic resonance (CMR) may reveal concealed pathological substrates. The aim of this multicenter study was to evaluate which VA characteristics predicted CMR abnormalities. Methods and Results We enrolled 251 consecutive competitive athletes (74% males, median age 25 [17‐39] years) who underwent CMR for evaluation of VA. We included athletes with >100 premature ventricular beats/24 h or ≥1 repetitive VA (couplets, triplets, or nonsustained ventricular tachycardia) on 12‐lead 24‐hour ambulatory ECG monitoring and negative family history, ECG, and echocardiogram. Features of VA that were evaluated included number, morphology, repetitivity, and response to exercise testing. Left‐ventricular late gadolinium‐enhancement was documented by CMR in 28 (11%) athletes, mostly (n=25) with a subepicardial/midmyocardial stria pattern. On 24‐hour ECG monitoring, premature ventricular beats with multiple morphologies or with right‐bundle‐branch‐block and intermediate/superior axis configuration were documented in 25 (89%) athletes with versus 58 (26%) without late gadolinium‐enhancement ( P <0.001). More than 3300 premature ventricular beats were recorded in 4 (14%) athletes with versus 117 (53%) without positive CMR ( P <0.001). At exercise testing, nonsustained ventricular tachycardia occurred at peak of exercise in 8 (29%) athletes with late gadolinium‐enhancement (polymorphic in 6/8, 75%) versus 17 athletes (8%) without late gadolinium‐enhancement ( P =0.002), ( P <0.0001). At multivariable analysis, all 3 parameters independently correlated with CMR abnormalities. Conclusions In athletes with apparently idiopathic VA, simple characteristics such as number and morphology of premature ventricular beats 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.

Cardiac Magnetic Resonance to Detect the Underlying Substrate in Patients with Frequent Idiopathic Ventricular Arrhythmias

“…Although one study showed that the PVC burden was higher in patients with abnormal CMR findings [ 7 ], our study confirmed previous observations that the number of PVCs was not predictive of pathological CMR findings [ 5 , 29 ]. On the contrary, one study in athletes found that those with no scarring on LGE imaging had a higher PVC burden than athletes with LGE findings [ 30 ]. This may be explained by the fact that ectopic foci located in the outflow tract of the ventricles may give rise to very frequent PVCs [ 31 ].…”

Role of Cardiac Magnetic Resonance Imaging in the Evaluation of Athletes with Premature Ventricular Beats

“…The scar often showed a subepicardial/midmyocardial distribution (non-ischemic) and was more likely when PVBs depicted an RBBB-like pattern or multiple morphologies, or when non-sustained VT was recorded during exercise testing. Conversely, a high number of PVBs (>3300/day) predicted a normal CMR (Figure 5) [23].…”

“…Biventricular myocardial fibrosis was found in the postmortem examination of a famous Italian footballer who died suddenly during a competition [20]. No matter the cause, a NLVS should be regarded as clinically significant because it is a possible substrate for macro-reentrant VT [21][22][23][24].…”

“…Figure 5. Summary of the main findings of a multicenter study on 251 athletes with ventricular arrhythmias, normal echocardiography and unremarkable ECG findings and a negative family history.Reproduced with permission from[23].…”

Premature ventricular complexes : Systematic review, evaluation and management

“…The appearance of PVCs or even VT during exercise is more frequent in individuals with SHD, fact that implies a worse prognosis and a need for deeper evaluation. In a study with otherwise apparently healthy athletes, those with repetitive PVCs during exercise were found to represent a high-risk subgroup and the presence of exercise-induced non-sustained polymorphic VT was associated with a probability of an underlying LV scar of 67% (22,23). Anyway, patients with idiopathic PVCs who develop monomorphic VT during exercise testing are still considered to have good prognosis, but a thorough investigation is necessary to ensure its benign nature (24).…”