Revista de Medicina Desportiva (English) September 2018 - Page 24

Rev. Medicina Desportiva informa, 2018; 9(5):22–24. Hypertrophic cardiomyopathy Dr. Hélder Dores Cardiologist. Hospital of the Army and Hospital da Luz. Lisbon, Portugal Hypertrophic cardiomyopathy (HC) is one of the most frequent causes of sudden death in athletes. Is the EKG a good help for the diagnosis? Yes! Despite the diagnosis of HC is an imaging-parietal thick- ness higher than 15mm in the absence of other overload conditions, the EKG is a very important to evaluate patients with HC. This cardiomyopathy is classically characterized by a progressive cascade of changes, in which the electrical changes identified in the EKG are shown earlier than the structural phe- notypic changes. In this context, the inclusion of the EKG in the sports medical exam allows early diagnosis of many cases of HC, described as the leading cause of sudden death in young athletes. Although the vast majority of patients with HC have EKG changes, these are very little specific, and the most frequent changes are in ventricular repolarization, namely inverted T waves. Since the inverted T waves are also frequent in the athlete’s EKG without pathology, the distinction between physiologi- cal adaptations and pathological changes is fundamental and is sometimes very difficult. The inver- sion of T waves in two contiguous leads, notably in the lateral and inferior leads (except III), should raise the suspicion of cardiomyo- pathy and deserve complementary evaluation. On the other hand, the inversion in the anterior-septic lead is difficult to value, and it is crucial to know the demographic charac- teristics of the athlete. For example, the inversion of T waves in V1-V4 preceded by elevation of the point 22 september 2018 www.revdesportiva.pt J / segment ST in black athletes is considered physiological, as is the inversion until V3 in athletes under the age of 16 years, in which it can correspond to the juvenile standard. The pathological changes in the athlete’s EKG should motivate sub- sequent complementary diagnostic tests. However, despite the absence of pathological changes in these exams in asymptomatic athletes with normal physical examination does not contraindicate the practice of competitive sport, the follow-up is justified. It is shown in several studies that a significant percentage of these individuals can develop the long-term HC phenotype. The EKG is thus essential in the evaluation of athletes and of patients with HC, stressing the need to apply specific criteria for their interpretation in the athlete, aim- ing to reduce the impact of their main limitation, the high rate of false-positives due to physiological adaptations induced by the physical exercise. ... But the echocardiogram is fundamental, isn’t it? The echocardiogram is critical in evaluating the HC. Overall, it consti- tutes the first-line image examina- tion for the athlete’s morphological and functional cardiac evaluation, especially for its high accessibility, diagnostic capacity and low cost. In fact, in most cases of HC, it is the transthoracic echocardiogram that establishes the diagnosis of the disease. In addition to the detection of parietal hypertrophy, this examina- tion may provide other very impor- tant information for the diagnosis of HC, such as: asymmetric left ventricular hypertrophy, diastolic dysfunction, apical aneurysms, left ventricular exit chamber obstruc- tion, anomalies on the mitral valve unit and of the insertion of the capillary muscles. However, the interpretation of these changes is often limited by the overlap between pathological hypertrophy and physi- ological hypertrophy induced by physical exercise. Many athletes present characteristics located in the so-called grey zone, in which a) a) Physiologic change: Homem, male, black race, years old, track and field, about 12h of training / week Alteração fisiológica: negro, 27 27 anos, atletismo, ±12h/treino/semana b) b) Athlete with CM: Homem, male, caucasian race, years old, football player, about 8 hours of training / week Atleta com MCH: caucasiano, 22 22 anos, futebol, ±8h/treino/semana Figure 1 – Non-pathological EKG of a black-race athlete (a) and an athlete’s EKG with confirmed diagnosis of HC (b).