Determinants of the athlete’s heart: a cardiovascular magnetic resonance imaging study

Abstract

Regular physical training is associated with several physiological alterations in cardiac structure and function to promote a substantial and sustained increase in cardiac output during intensive exercise. Increased cardiac mass, chamber size, left ventricular wall thickness, stroke volume and enhanced diastolic filling are well established features of the 'athlete's heart'. Large echocardiographic studies in athletes have shown that the majority reveal modest increases in cardiac dimensions compared with the sedentary population; however, both qualitative and quantitative differences in cardiac dimensions among athletes are governed by several factors including age, sex, size, ethnicity and the type and intensity of the sporting discipline. A small proportion of male athletes engaging in endurance sports and black men engaging in sports associated with explosive bursts of sprinting may develop a substantial increase in cardiac dimensions that overlaps with cardiomyopathy.Over the past two decades, there has been an exponential increase in the utility of cardiovascular magnetic resonance (CMR) imaging for assessing athletes with marked repolarisation changes on the ECG and those with cardiac dimensions exceeding normal ranges, particularly with respect to left ventricular wall thickness. 1 CMR is recognised for its superior temporal and spatial resolution and its ability to provide detailed characterisation of the ventricular myocardium. Functional cine CMR sequences permit accurate quantification of left and right ventricular volumes and left ventricular mass (LVM). CMR with gadolinium contrast bolus provides the unique ability to detect myocardial inflammation and fibrosis. T1 mapping enables the detection of interstitial fibrosis and T2 mapping is invaluable for detecting myocardial oedema in athletes with myocarditis. Other uses of CMR include stress perfusion for the assessment of myocardial ischaemia. Given the large number of athletes being subjected to CMR, there is a clinical necessity to provide normal CMR values for cardiac dimensions in athletes that account for various demographics that impact on cardiac size. In addition, CMR has the potential to provide an in-depth understanding of mechanisms for cardiac enlargement, but probably more importantly to assist in the differentiation between physiological cardiac enlargement and mild or subtle manifestations of cardiomyopathy, especially in the absence of myocardial scar.Previous CMR studies in healthy athletes have been confined to white men engaging in a limited number of sporting disciplines, making them difficult to generalise to all athletic populations. 2 In a recent meta-analysis involving 983 healthy male competitive athletes aged between 18 and 55 years, D'Ascenzi et al. provided 5th and 95th percentiles for absolute and indexed ventricular volumes, ventricular mass and ejection fraction. 3 Athletes, particularly those participating in endurance sport, showed larger mean ventricular volumes compared to non-athletes. Irrespective of the sporting...

Role of cardiac magnetic resonance imaging in troponinemia syndromes

“…LV dilatation is less severe as compared to the RV dilatation. Stress echocardiography observation of improvement in LVEF by > 11%, and presence of mid-wall LGE may help to discriminate between AHS and pathological dilated cardiomyopathy[ 95 , 96 , 110 , 111 ] but this has not yet been investigated in large studies. In a meta-analysis performed by D’Ascenzi et al [ 102 ], in high-performance athletes, RV end-diastolic volume (EDV) and end-systolic volume (ESV) exhibited the greatest relative increase in ventricular remodelling, compared to baseline parameters.…”