Specific Cardiovascular Diseases and Competitive Sports Participation: Left Ventricular Hypertrabeculation

Abstract

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.

Clinical Application

1.1 Questions

• 1. A 17-year-old male, Caucasian, competitive rower is found to have features of LVNC on cardiac MRI, following a private health screening. He has no family history of cardiac disease or sudden cardiac death. His electrocardiogram is normal, and an echocardiogram shows an ejection fraction of 50% and normal LV function. What is the diagnosis, and can he continue to compete in his chosen sport?

• 2. A 23-year-old male, Afro-Caribbean, professional football player presents with syncopal episodes, shortness of breath on exertion and palpitations. His maternal Grandmother died aged 46 in unclear circumstances. His electrocardiogram shows deep inferolateral T-wave inversion. His echocardiogram shows an ejection fraction of 43% and normal LV function. A cardiac MRI shows features of mild myocardial non-compaction. What further tests would you order and how would you manage this patient?

• 3. A 34-year-old female, Caucasian, air race pilot has an annual health check as requested by her insurance company. She is asymptomatic apart from a recent bad cold. Her latest electrocardiogram shows ST depression. An echocardiogram shows an ejection fraction of 49% and normal LV dimensions and function. Cardiac MRI shows evidence of myocardial non-compaction. Ambulatory monitoring and an exercise electrocardiogram show no arrhythmias and no episodes of non-sustained VT. Can she compete in the air show this weekend?

1.2 Answers

• 1. Although this young athlete has a feature of LVNC on imaging, in the absence of symptoms, positive family history, abnormal ECG patterns and, most importantly, impaired LV function, he has no restriction for any competitive sports.

• 2. This patient is symptomatic with concerning features on electrocardiogram and cardiac MRI. He should undergo further testing: an exercise stress test and peak exercise echocardiogram and should refrain from competitive sport until a diagnosis has been confirmed.

• 3. This air race pilot should not compete in the air show this weekend and should refrain from further air races. She is asymptomatic with no prior history of unexplained syncope and has no complex ventricular arrhythmias or episodes of non-sustained VT. She may compete in all competitive sports except those where occurrence of syncope may cause serious harm or death to herself or others. She should be encouraged to consider a ground sport if she wishes to continue competing.