Specific Cardiovascular Diseases and Competitive Sports Participation: Left Ventricular Hypertrabeculation

Left Ventricular Non-Compaction (LVNC) is a relatively rare (0.3% prevalence) cardiac condition, characterised by prominent trabeculations and deep recesses of the endomyocardial tissue of the left ventricle. LVNC may be congenital or acquired and is thought to be reversible with changes in cardiac preload. Athletes and pregnant women have been shown to demonstrate features of left ventricular (LV) hypertrabeculation suggesting that, in low risk cohorts, LVNC may simply be a result of increased cardiac preload. Athletic individuals are usually asymptomatic and are often diagnosed incidentally during routine imaging evaluation. However, currently there is no gold standard for the diagnosis of LVNC, and existing echocardiographic diagnostic criteria is based on the ratio of compacted versus non-compacted LV myocardium on echocardiography and vary in terms of measurements in end-diastole or end-systole. Similarly, there are also cardiac magnetic resonance imaging criteria available for diagnosis. As a high proportion of athletes meet the criteria for a diagnosis of LVNC, without exhibiting other clinical features of the disorder and in the absence of a positive family history, it may be that increased LV trabeculations are of limited significance in this group and simply form part of the ‘athlete’s heart’. The presence of LV hypertrabeculation in asymptomatic athletes in the absence of a family history does not require further evaluation. Athletes with an unequivocal diagnosis of LVNC should be advised to participate in leisure activities only and be closely monitored. The echocardiographic and cardiac MRI diagnostic criteria for LVNC is based on small cohorts and is not ethnically diverse, risking overdiagnosis in some populations. Clearer diagnostic criteria, modified for ethnicity, is required. There is a poor genotype and phenotype correlation, so it is important to look at the overall clinical picture. However, prognosis of LVNC in low risk cohorts remains good.