Tackling an unmet need in sports cardiology: understanding exercise-induced cardiac remodelling and its clinical consequences

The field of sports cardiology has surpassed many hurdles over the past decades. From initial findings of cardiac enlargement by clinical examinations and chest radiographs, through the better phenotyping of exercise-induced cardiac remodelling (EICR) on electrocardiography, echocardiography and cardiac MRI, our understanding of the spectrum of the athlete’s heart has greatly advanced.

The limits of research on EICR

Prior scientific endeavours have largely focused on describing EICR in healthy athletes and contrasting this with pathological mimics. For example, early studies contrasted the ‘physiological’ left ventricular wall thickening associated with athlete’s heart to hypertrophic cardiomyopathy.1 These studies provided some invaluable clinical tools enabling better discrimination of physiology from pathology, although recent observations have questioned the dichotomous separation between healthy ‘physiological’ myocardial hypertrophy and disease.

Several questions exemplify current knowledge gaps and the limits of our understanding of EICR. Why does EICR incompletely resolve on detraining? Why does myocardial scar exist in some of the fittest athletes? Why are arrhythmias more prevalent in ostensibly healthy athletes? Could certain features of EICR predispose some athletes to arrhythmias and thus discriminate between athletes with a lower and higher arrhythmic risk?

Defining the determinants of exercise-induced cardiac remodelling

Despite all the advances, there are persisting uncertainties regarding the determinants and prognosis of EICR. Foremost is the need to dissect …