Dr. Luis Serratosa
The meaning of isolated nonischemic left ventricular (LV) late gadolinium enhancement (LGE) at contrast-enhanced cardiac magnetic resonance (CE-CMR) in athletes with apparently idiopathic ventricular arrhythmias (VA) and/or repolarization abnormalities is still not clear. While a nonischemic subepicardial/midmyocardial LV scar can be found in several myocardial diseases at risk of sudden cardiac death (SCD), the presence of spotty LGE at the junction of the right ventricle (RV) with the interventricular septum has been considered as part of the physiological adaptations to long term intense endurance training.
In order to characterize their clinical and imaging profile and arrhythmic outcome, the present study compared 35 athletes with VA (frequent PVB or complex VA) and LV nonischemic subepicardial/midmyocardial LGE (group A) with 38 athletes showing VA and a totally negative CE-CMR (group B) and a control group of 40 healthy athletes (group C).
A stria LGE pattern with subepicardial/midmyocardial distribution, mostly involving the lateral LV wall (89%), was found in 27 (77%) of group A athletes versus 0 controls, whereas a junctional spotty LGE pattern was respectively found in 11 (31%) versus 10 (25%) of the athletes. Among the 27 athletes with a stria pattern, all had VA with a predominant right bundle branch block (RBBB) morphology, 13 (48%) showed repolarization abnormalities and 5 (19%) hypokinesis of the LV lateral wall on echocardiography. Most of the athletes with no or a junctional spotty LGE pattern showed VA with a predominant left bundle branch block (LBBB) morphology, and no ECG or echocardiographic abnormalities. During the 38±25 months follow-up period, 6 of the 27 (22%) athletes with a stria pattern experienced malignant arrhythmic events such as appropriate ICD shocks (4), sustained ventricular tachycardia (1) and SCD (1) compared with no or LGE spotty pattern and controls.
Although still a relatively small number, the present study reports results of the largest cohort of athletes with VA and LV LGE. The pathogenetic hypothesis is that the stria pattern LV scar may reflect a left-dominant arrhythmogenic right ventricular cardiomyopathy (ARVC). The inherited nature of this cardiomyopathy was at least partly supported in this study by the family history of SCD in 3 of the group A athletes and the clinical evidence of familial recurrence of the disease in 2 athletes. Because of its focal and/or non-transmural wall distribution these stria pattern LV scars may be undetectable by echocardiography, so performing CE-CMR in athletes with frequent PVB or complex VA with a predominant RBBB morphology should be at least considered. ECG abnormalities (T-wave inversion in the inferolateral leads and/or low QRS voltages in the limb leads) may help in suspecting the disease at a presymptomatic stage.
The appropriate management of athletes with a nonischemic stria pattern LV scar and frequent PVB or complex VA, especially if worsened by exercise, should include adequate medical treatment, accurate evaluation (including family screening) and prudential advice to refrain from physical exercise or sports with high cardiovascular demand.
Further prospective studies with larger samples of athletes showing a nonischemic LV LGE (stria and spotty pattern), with and without VA, are needed to provide adequate guidelines on risk stratification and management of these individuals.
The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.
Nonischemic Left Ventricular Scar as a Substrate of Life-Threatening Ventricular Arrhythmias and Sudden Cardiac Death in Competitive Athletes
Zorzi A, Perazzolo Marra M, Rigato I et al.
Circ Arrhythm Electrophysiol. 2016 Jul;9(7). pii: e004229. doi: 10.1161/CIRCEP.116.004229
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