ABC | Volume 112, Nº3, March 2019

Updated The Brazilian Society of Cardiology and Brazilian Society of Exercise and Sports Medicine Updated Guidelines for Sports and Exercise Cardiology - 2019 Arq Bras Cardiol. 2019; 112(3):326-368 Recommendation grade: III. Evidence level: B. Athletes with a definite DCM diagnosis but a low risk profile (asymptomatic, no family history of SD, slightly reduced ejection fraction, normal pressure response to exercise and no complex ventricular arrhythmias) could participate in low-to- moderate intensity dynamic exercise and low-intensity static exercise (recommendations IA and IB). These recommendations apply to competitive exercise. Physical activity of a therapeutic nature (cardiac rehabilitation) is indicated for all DCM and heart failure patients. 145 4.5. Non-Compacted Cardiomyopathy Non-compacted cardiomyopathy is a rare cardiac disease that has been recently recognized. It is due to embryonic interruption of myocardial compaction and is characterized by segmental thickening of the LV walls that consists of two layers: a compacted epicardial layer and an endocardial layer with marked trabeculations and deep intratrabecular recesses that are filled by blood flow. In non-compacted cardiomyopathy, left ventricular capacity is usually increased and the ejection fraction is reduced. 146,147 Although considered a rare condition by some researchers, the incidence and prevalence of non-compacted cardiomyopathy are uncertain. Using echocardiography, a study at a large institution found a prevalence of 0.05%. Among HF patients, the prevalence of non-compacted cardiomyopathy is 4%. 148 Diagnosis is quite difficult due to the lack of clear criteria, as well as the condition’s heterogeneous clinical spectrum and the usual need for MRI for a reliable diagnosis. This disease may be asymptomatic or present with HF, ventricular and/or atrial arrhythmias, pre-excitation, thromboembolic events or SD. However, the risk of adverse consequences, including SD, seems to be associated with the degree of LV systolic dysfunction and/or ventricular tachycardia. 149 There are no universally accepted criteria or precise guidelines for morphological diagnosis. However, a non- compacted/compactedmyocardium ratio of > 2.1:1 at the end of systole in an echocardiogram or of 2.3:1 at the end of systole in CMRI is currently the most widely accepted criterion. 150 Non-compacted cardiomyopathy can be found alone or combined with congenital heart defects, neuromuscular disorders or as part of genetic syndromes. 149 It is a genetically heterogeneous disease, with familial or sporadic cases, and with pathogenic mutations involving the cytoskeleton, mitochondria, sarcomeres and z-line proteins. Therefore, different forms have been described: autosomal dominant, autosomal recessive, X-linked, and with mitochondrial patterns of inheritance, although the most common form has an autosomal dominant trait. 146 4.5.1. Sports and Non-Compacted Cardiomyopathy Neither the extent to which physical training can alter non-compacted cardiomyopathy nor the prevalence of non- compacted LV morphology among healthy athletes have been determined. 151,152 Since forensic reports of SD in young athletes do not include non-compacted cardiomyopathy as a possible cause, it is not possible to apply risk stratification strategies for new patients with this disease. Recent studies have found a higher prevalence of increased LV trabeculation among athletes than controls (18.3% vs. 7%). It is believed that these abnormalities represent a non-specific epiphenomenon that increases with higher image resolution in echocardiography. In addition, increased LV trabeculation or isolated echocardiographic criteria for cardiomyopathies are likely to be of little significance andmay be a part of the athlete’s heart. 153,154 Thus, not all athletes with isolated ventricular non-compaction should be diagnosed with non-compacted cardiomyopathy. Therefore, functional parameters such as ejection fraction must be considered in patient management. 154 4.5.1.1. Recommendations for Athletes Diagnosed with Non-Compacted Cardiomyopathy Athletes with an unequivocal diagnosis of non-compacted cardiomyopathy and compromised systolic function, major ventricular tachyarrhythmias in Holter monitoring or at an exercise testing or a history of syncope should not participate in competitive sports, with the possible exception of low- intensity sports (class IA), at least until more clinical information becomes available. Recommendation grade: III. Evidence level: C. 4.6. Chagas Disease Chagas disease continues to be one of the most important causes of non-ischemic cardiomyopathy in Latin America. Approximately 8-10million people are estimated to be infected with Trypanosoma cruzi , 155 and this protozoa is responsible for approximately 12,000 deaths per year. 156 The disease usually manifests itself in 30% to 40% of those infected, and clinical findings usually appear 10 to 30 years after initial infection. 157 Cardiac arrhythmias and SD are common and may occur at any stage of progression, even in individuals without significant structural disease. 158,159 Sustained ventricular tachycardia is the main cause of SD, and is associated with LV dysfunction, syncope and non-sustained ventricular tachycardia in Holter monitoring or the exercise testing. 160,161 In addition, sinus node dysfunction, atrioventricular and intraventricular conduction disorders are common findings in patients with Chagas disease and may progress to complete atrioventricular block. Few studies have evaluated the risk of SD in Chagas patients during intense exercise, and a lack of symptoms does not exclude the presence of cardiomyopathy, even in high-level athletes. 162 Diagnosis involves epidemiological and serological evaluation (immunofluorescence). ECG and echocardiogram facilitate diagnosis of cardiomyopathy and conduction disorders. An exercise stress testing or a CPET, MRI, Holter monitoring and even electrophysiological study can more accurately assess the risk of SD. The exercise recommendations are similar to those for individuals with DCM. 344