Left Ventricular Trabeculation: Arrhythmogenic and Clinical Significance in Elite Athletes

The spectrum of eccentric left ventricular hypertrophy in endurance sports disciplines

Endurance sports disciplines largely differ in terms of specific training and event modalities, likely resulting in diverse morpho-functional cardiac changes. Our study aims to assess elite athletes engaged in different endurance disciplines and describe cardiac remodelling in each. We enrolled 282 Olympic athletes (58.5% males, mean age 26.7 ± 4.7) practising long-distance running (57, 20.2%), triathlon (18, 6.4%), canoeing/rowing (76, 26.9%), cycling (65, 23%), long-distance swimming (21, 7.4%), cross-country skiing & biathlon (45, 16%). athletes underwent ECG, echocardiogram and exercise stress-test. Eccentric LV hypertrophy (EH) was present in 73.8% of athletes, without gender differences (p = 0.847), varying greatly among disciplines (p = 0.0005). Triathlon (94.4%) and cycling (87.7%) showed the highest prevalence. The largest LV volumes were observed in triathlon-athletes and cyclists (LVEDVi: males, p = 0.009, females, p = 0.002). The lowest LV dimensions were found in rowing/canoeing (males: p < 0.0001; females: p < 0.0001). Long-distance runners and swimmer presented intermediate extent of LV remodelling. Positive correlation between hours of training and LVMi (p = 0.0004) and LVEDVi (p = 0.048) was observed among cyclists. Indeed, cyclists with the highest EH (i.e., lowest LVMi\LVEDVi ratio) achieved the highest workload at exercise stress-test (p = 0.045) and better athletic achievements. Among endurance athletes, cyclists and triathletes present the most marked extent of LV EH, while canoeists and rowers the lowest degree, with major increase in LV mass. Intra-group analysis showed an association between eccentric hypertrophy and superior exercise capacity and higher athletic performances that may be related to an increased stroke volume and cardiac output, which improve cardiovascular efficiency during endurance exercise. These findings could be useful both for clinicians in identifying potential health issues in athletes and for coaches when assessing athletes' training status.

How to Approach Left Ventricular Hypertrabeculation: A Practical Guide and Literature Review

Left ventricular hypertrabeculation is one of the most debated conditions in modern cardiology. Many studies have tried to characterise this disease by addressing the various clinical risks and diagnostic tools, but its very nosological existence is currently being challenged. The latest ESC guidelines on cardiomyopathies state that it should be addressed as a morphologic trait rather than an intrinsic disease of the cardiac muscle. Despite the huge number of diagnostic criteria and possible phenocopies, no specific consensus identifies a specific flowchart regarding the management of patients with suspected hypertrabeculation. This review aims to provide a clinical approach for patients with a phenotypical appearance of excessive trabeculation.

Left Ventricular Hypertrabeculation (LVHT) in Athletes: A Negligible Finding?

Left ventricular hypertrabeculation (LVHT) used to be a rare phenotypic trait. With advances in diagnostic imaging techniques, LVHT is being recognised in an increasing number of people. The scientific data show the possibility of the overdiagnosis of this cardiomyopathy in a population of people who have very high levels of physical activity. We describe the case of a young athlete with no medical history, who presented with syncope during a marathon running race. Initial evaluation showed elevated troponin I; transthoracic echocardiography showed a trabeculated ventricle and subsequent cardiac magnetic resonance (CMR) revealed left ventricular hypertrabeculation (LVHT). During subsequent evaluation by tilt table testing, vasovagal syncope was identified as the likely aetiology of the syncope. The patient was advised to cease sports and stimulants like caffeine use. At the 29-month follow-up, CMR showed the normalisation of the non-compacted to compacted myocardial ratio and an improvement in left ventricular function, with no further syncopal episodes reported. This is an example of the physiological hypertrabeculation of the LV apex in a recreational endurance athlete, with the normalisation of the non-compacted to compacted myocardial layer ratio after detraining. Physiological hypertrabeculation, a benign component of exercise-induced cardiac remodelling, must be differentiated from non-compaction cardiomyopathy and other pathologies causing syncope. This case underscores the importance of distinguishing physiological hypertrabeculation from pathological LVHT in athletes, highlighting that exercise-induced cardiac remodelling can normalise with detraining.