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5.5.3 Exercise recommendations in individuals with left ventricular non-compaction LV non-compaction (LVNC) is an unclassified cardiomyopathy characterized by prominent trabeculation and deep recesses that communicate with the LV cavity.403,404 Clinical presentation of LVNC includes progressive LV systolic dysfunction, ventricular tachyarrhythmias, and thromboembolic events.404 Athletes often demonstrate LV hypertrabeculation and up to 8% fulfil the echocardiographic criteria for a diagnosis of LVNC.405 It is hypothesized that an increased cardiac preload may unmask LV trabecular morphology.406 Therefore, among athletic individuals, the suspicion of LVNC should only be considered in those who fulfil echocardiographic criteria for LVNC but also have either LV systolic dysfunction (EF < 50%), symptoms suggestive of cardiac disease, or a positive family history of LVNC.407409 Additional echocardiographic criteria include a very thin compacted epicardial layer (5 mm in end-diastole on CMR, or <8 mm in systole) and abnormal myocardial relaxation (average E’ < 9 cm/s on tissue Doppler imaging).404,405,410,411 Such athletes will require further assessment with CMR, exercise echocardiography, and Holter monitor to assess the presence of LV fibrosis, cardiac thrombi, contractile reserve, and exercise-induced complex arrhythmias.405,406

5.5.3.1 Risk stratification The clinical outcomes of LVNC are determined by the presence of symptoms, severity of LV dysfunction, and the nature of the VAs. There are no reported adverse cardiac events in the absence of LV dysfunction regardless of the severity of LV trabeculation.405409

5.5.3.2 Follow-up Regular follow-up is recommended for individuals with LVNC. New symptoms should prompt interruption of exercise and re-evaluation. 5.5.4 Exercise recommendations in individuals with dilated cardiomyopathy DCM is characterized by LV or biventricular systolic dysfunction with or without dilatation that are not explained by abnormal loading conditions or CAD. Possible causes include genetic predisposition, myocarditis, drugs, toxins, peripartum cardiomyopathy, and, in some cases, the cumulative effect of more than one factor.412

The clinical spectrum of disease may range from a mild phenotypic expression characterized by absence of symptoms, isolated LV dilatation and normal or low-normal systolic function, to an overt disease phenotype with limiting symptoms and significant systolic dysfunction. Ventricular arrhythmias are common in DCM, particularly in individuals with previous myocarditis, or with lamin A/C mutations and filamin C mutations.413,414 The risk of SCD in DCM is 23% per year and increases with lower EF and higher NYHA class.415 Exercise training improves functional capacity, ventricular function, and quality of life in patients with DCM and should therefore be considered as an integral part of the management of affected individuals.416,417 However, intensive exercise and competitive sports are reported as a cause of SCD in DCM. 28,46,58,413,418 LV cavity enlargement in trained individuals that is not associated with systolic dysfunction and outside the context of a familial disease, represents a benign physiological adaptation if it is consistent with the type of sports participated (usually, endurance sports) and the body size of the athlete. Conversely, a mildly reduced EF (4550%) in an athlete with an enlarged LV cavity should not merely be considered as a normal adaptation. In such cases assessment of LV function during exercise may provide important diagnostic clues.319 Failure to increase EF at peak exercise by >10% compared with the baseline value may suggest a pathological condition.319,419,420 The presence of diastolic dysfunction or reduced peak oxygen consumption on CPET may also provide supporting information for the differential diagnosis. CMR has emerged as an important tool for the diagnosis and risk stratification of DCM.

Recommendations for exercise in individuals with left ventricular non-compaction cardiomyopathy

Recommendation for diagnosis Classa Levelb

A diagnosis of LVNC in athletic individuals should be considered if they fulfil imaging criteria, in association with cardiac symptoms, family history of LVNC or cardiomyopathy, LV systolic (EF<50%) or diastolic (E’<9 cm/s) dysfunction, a thin compacted epicardial layer (<5 mm in end-diastole on CMR, or <8 mm in systole on echocardiography), or abnormal 12-lead ECG.404,405,410,411 IIa B Exercise recommendations Participation in high-intensity exercise and all competitive sports, if desired, with the exception where syncope may cause serious harm or death, may be considered in asymptomatic individuals with LVNC and LVEF>_50% and absence of frequent and/or complex VAs. IIb C Participation in recreational exercise programmes of low to moderate intensity, if desired, may be considered in individuals with LVEF 4049% in the absence of syncope and frequent or complex VAs on ambulatory Holter monitoring or exercise testing. IIb C

Continued Participation in high- or very high-intensity exer-

cise including competitive sports, if desired, may be considered for individuals who are gene positive for LVNC but phenotype negative (with the exception of lamin A/C or filamin C carriers). IIb C Participation in high-intensity exercise or competitive sports is not recommended in individuals with any of the following: symptoms, LVEF<40% and/or frequent and/or complex VAs on ambulatory Holter monitoring or exercise testing. III C Follow-up and further considerations Annual assessment for risk stratification is recommended for individuals with LVNC and genotypepositive/phenotype-negative individuals who exercise on a regular basis. I C

CMR = cardiac magnetic resonance; ECG = electrocardiogram; EF = ejection fraction; LV = left ventricular; LVEF = left ventricular ejection fraction; LVNC = left ventricular non-compaction; VA = ventricular arrhythmia. aClass of recommendation. bLevel of evidence. Downloaded from academic.oup.com/eurheartj/article/42/1/17/5898937 by guest on 07 October 2026