Role of extensive diagnostic workup in young athletes and nonathletes with complex ventricular arrhythmias

Abstract

Total word count: 4862 24 This research did not receive any specific grant from funding agencies in the public, commercial, 25 or non-profit sectors. 26 2 The authors have no conflicts to disclose. Abstract 41 Background. Ventricular tachyarrhythmias (VA) represent the first cause of death in athletes. The 42 difference between electroanatomic substrate in athletes and non-athletes with complex VA is 43 unknown. 44 45 Objective. To compare the electroanatomic substrate of complex VA in athletes versus non-46 athletes. 47 48 Methods. We prospectively enrolled young athletes and non-athletes with VA. Patients underwent 49 2D echo, cardiac magnetic resonance (CMR), coronary angiography, 3D-electroanatomic mapping 50 (3D-EAM) and 3D-EAM guided endomyocardial biopsy (EMB). Follow-up included 24h ECG 51 Holter or ICD/loop recorder interrogation for VA recurrence.52 53Results. We enrolled 33 consecutive patients, 18 (56%) competitive athletes and 15 (44%) non-54 athletes. Left and right ventricular (LV and RV) findings by echo and CMR did not show 55 structural disease. Nine (50%) athletes were asymptomatic compared to 1 (7%) non-athlete 56 (p<0.05). Unifocal origin of VA was reported in 14 (93%) athletes and in 17 (94%) non-athletes. 57Athletes showed a larger RV unipolar than bipolar scar (18 ± 17 cm 2 versus 3 ± 3.8 cm 2 , p= 0.04). 58 Diagnostic yield of EMB was 50% in athletes and 40% in non-athletes. Among athletes, the final 59 diagnosis was myocarditis in 2 cases, arrhythmogenic ventricular right cardiomyopathy and focal 60 replacement fibrosis in one case each. Among non-athletes, EMB revealed focal replacement 61 fibrosis in 4 cases. At median follow-up of 18.7 months, Kaplan Meyer curves showed lower VA 62recurrence in detrained athletes than non-athletes (53% versus 6%, p= 0.02). 64Conclusions. Our data showed the need for an extensive diagnostic work-up in apparently healthy 65 young patients with complex VA in order to characterize concealed cardiomyopathies. 66 67 4

The arrhythmogenic right ventricular cardiomyopathy in comparison to the athletic heart

“…In particular, these authors considered that a vigorous exercise and the related haemodynamic loading changes, through an increased oxygen demand and increased release of catecholamines/changes in free fatty acid metabolism, may lead to acute effects (right heart dilation, diastolic dysfunction), sub‐acute effects (overexpression of cardiac fibrotic markers, collagens,fibronectin‐1), and finally chronic effects (determining patchy areas of fibrosis, an ideal substrate for VA) 13,14 . Although many studies confirmed exercise‐induced RV fibrosis 21‐23 it is still debated to what extent the controversial “exercise‐induced" ARVC and the “Philippides cardiomyopathy” associated with potential pathological or physiological findings. A RV dilatation and hypokinesia were noted in at least one‐third of endurance athletes, compared with a potential LV impairment 24‐26 .…”

“…The authors concluded that chronic RV damage in endurance master athletes is unlikely, since the RV ejection fraction did not differ between the two groups, and no correlations were found for the LV/RV volumes and the ejection fraction with natriuretic peptide. 29 However, although it is clear that endurance sport may promote RV changes "compatible" with a diagnosis of ARVC, [21][22][23][24][25][26][27][28] the hypothesis of a definite "exercise-induced" cardiomyopathy is still questionable. Cardiac fibrosis and remodeling, although initially reversible, could eventually become permanent due to repeated myocardial injury.…”

Electroanatomic mapping‐guided endomyocardial biopsy in patients with apparently idiopathic ventricular arrhythmias

“…18 Besides necropsy, EMB studies performed in the 1980s and 1990s, provided major insights on possible myocardial disorders that may cause life-threatening VA with an apparently normal heart. [19][20][21][22][23][24][25][26][27][28][29][30][31] Clinical setting and major findings and peculiar features of these studies are summarized in Table 1. Although in most of these studies EMB processing was limited to histology, thus neither including immunohistochemistry nor molecular biology, pathological findings were reported in most patients, even those with a milder arrhythmic burden.…”

“…In the last decades several studies have documented that EMB represents an important tool not only in clinical practice but also for its application as a research tool in the fields of cardiomyopathy and arrhythmias [19][20][21][22][23][24][25][26][27][28][29][30][31] (Table 1).…”

“…Besides necropsy, EMB studies performed in the 1980s and 1990s, provided major insights on possible myocardial disorders that may cause life‐threatening VA with an apparently normal heart 19–31 . Clinical setting and major findings and peculiar features of these studies are summarized in Table 1.…”