Global and regional cardiac function in lifelong endurance athletes with and without myocardial fibrosis

Abstract

The aim of the present study was to compare cardiac structure as well as global and regional cardiac function in athletes with and without myocardial fibrosis (MF). Cardiac magnetic resonance imaging with late gadolinium enhancement was used to detect MF and global cardiac structure in nine lifelong veteran endurance athletes (58 ± 5 years, 43 ± 5 years of training). Transthoracic echocardiography using tissue-Doppler and myocardial strain imaging assessed global and regional (18 segments) longitudinal left ventricular function. MF was present in four athletes (range 1-8 g) and not present in five athletes. MF was located near the insertion points of the right ventricular free wall on the left ventricle in three athletes and in the epicardial lateral wall in one athlete. Athletes with MF demonstrated a larger end diastolic volume (205 ± 24 vs 173 ± 18 ml) and posterior wall thickness (11 ± 1 vs 9 ± 1 mm) compared to those without MF. The presence of MF did not mediate global tissue velocities or global longitudinal strain and strain rate; however, regional analysis of longitudinal strain demonstrated reduced function in some fibrotic regions. Furthermore, base to apex gradient was affected in three out of four athletes with MF. Lifelong veteran endurance athletes with MF demonstrate larger cardiac dimensions and normal global cardiac function. Fibrotic areas may demonstrate some co-localised regional cardiac dysfunction, evidenced by an affected cardiac strain and base to apex gradient. These data emphasize the heterogeneous phenotype of MF in athletes.

The “Extreme Exercise Hypothesis”: Recent Findings and Cardiovascular Health Implications

“…Schnell et al reported a case series of serious cardiac complications in Belgian athletes with isolated subepicardial fibrosis, such as non-sustained ventricular arrhythmias, symptomatic ventricular tachycardia, and progressive LV dysfunction [ 34 ]. British veteran athletes with myocardial fibrosis demonstrated normal cardiac function, but co-localized regional cardiac dysfunction was found in fibrotic areas, substantiated by evidence of an attenuated cardiac strain and base to apex gradient [ 38 ]. These observations suggest that the presence of myocardial fibrosis requires appropriate clinical follow-up to evaluate the possibility of future adverse cardiovascular outcomes.…”

Myocardial fibrosis — a new component of heart remodeling in athletes?

“…Последующие наблюдения за элитными спортсменами показали, что диффузный фиброз миокарда регистрируется у них в 4,6 раза чаще по сравнению с контрольными группами, может присутствовать при нормальных коронарных артериях, и занимать до 10% от объема сердечной мышцы [6]. В отдельных спортивных популяциях частота фиброза доходит до 50% [7], особенно у лиц с большими и длительными объемами нагрузок на выносливость. Подобные изменения могут не нарушать глобальную функцию миокарда, однако в фиброзно-модифицированных областях имеется региональная дисфункция, проявляющаяся в изменении напряжения и продольного градиента в миокарде, а конечно-диастолический объем и ОТС ЛЖ в таких случаях достоверно выше, чем у спортсменов без фиброза.…”

The Role of Cardiovascular Magnetic Resonance in Sports Cardiology; Current Utility and Future Perspectives

“…On the other hand, Tahir et al [ 47 ••] demonstrated in 83 asymptomatic triathletes using LGE and ECV CMR focal non-ischemic MF in 9 of 54 (17%) males but in none of the female triathletes. In lifelong veteran endurance athletes, MF has been reported near the septal insertion points of the RV free wall in 37% of the athletes with just one subject exhibiting sub-epicardial lateral wall fibrosis [ 51 ]. This phenotype seems to differ from that in the general population, which may be relevant for the underlying mechanisms and clinical prognosis of MF in apparently healthy athletes.…”

“…The presence of MF is an important risk factor for adverse cardiac outcomes in clinical populations. However, the prognostic value of MF has not been extensively studied in athletic population [ 51 ]. The impact of lifelong exercise training is still a matter of ongoing debate.…”

“…The impact of lifelong exercise training is still a matter of ongoing debate. Although there are data supporting a U-shaped association between exercise volume and cardiovascular risk, most available evidence suggests a curvilinear relationship, with greater health benefits at larger exercise doses [ 51 , 57 ]. Several studies have identified the presence of LGE in the heart of extensively trained veteran athletes.…”