Arquivos Brasileiros de Cardiologia (Sep 2005)
Hipertrofia ventricular esquerda do atleta: resposta adaptativa fisiológica do coração Left ventricular hypertrophy of athletes: adaptative physiologic response of the heart
Abstract
OBJETIVO: Verificar se a hipertrofia ventricular esquerda (HVE) de atletas competitivos de resistência (maratonistas) representa processo adaptativo, puramente fisiológico, ou se pode envolver aspectos patológicos em suas características anatômicas e funcionais. MÉTODOS: De novembro de 1999 a dezembro de 2000, foram separados consecutivamente de 30 maratonistas em atividade esportiva plena, idade inferior a 50 anos, com HVE, previamente documentada, e sem cardiopatia subjacente. Foram submetidos aos exames: clínico, eletrocardiograma, ecodopplercardiograma, e teste ergométrico (TE). Quinze foram sorteados para realizar, também, teste ergoespirométrico e ressonância magnética (RM) do coração. RESULTADOS: Nos TE, todos apresentavam boa capacidade física cardiopulmonar, sem evidências de resposta isquêmica ao exercício, sintomas ou arritmias. No ecodopplercardiograma, os valores do diâmetro e espessura diastólica da parede posterior do ventrículo esquerdo (VE), do septo interventricular, massa do VE e diâmetro do átrio esquerdo, foram significativamente maiores que os do grupo de não atletas, com idades e medidas antropométricas semelhantes. A média da massa do VE dos atletas indexada à superfície corpórea (126 g/m2) foi significativamente maior que a do grupo controle (70 g/m2) (pOBJECTIVE: To verify whether left ventricular hypertrophy (LVH) of elite competition athletes (marathoners) represents a purely physiological, adaptative process, or it may involve pathological aspects in its anatomical and functional characteristics. METHODS: From November 1999 to December 2000, consecutive samples from 30 under 50-year-old marathoners in full sportive activity, with previously documented LVH and absence of cardiopathy were selected. They were submitted to clinical exams, electrocardiogram, color Doppler echocardiogram and exercise treadmill test (ETT). Fifteen were assorted to be also submitted to ergoespirometric test and heart magnetic resonance imaging (MRI). RESULTS: In ETT, all of them showed good physical pulmonary capacity, with no evidences of ischemic response to exercise, symptoms or arrhythmias. In Doppler echocardiogram, values of diameter and diastolic thickness of LV posterior wall, interventricular septum, LV mass and left atrium diameter, were significantly higher when compared to non-athlete control group, with similar ages and anthropometric measurements. The mean of LV mass of athletes indexed to body surface (126 g/m2) was significantly greater than the one in control group (70 g/m2) (p<0.001). Magnetic resonance imaging (MRI) showed there was not impairment of contractile strength or LV performance, and values of end diastolic volume, end systolic volume and EF within limits of normality. On the other hand, average ventricular parietal mass, 162.93±17.90 g, and LV parietal thickness, 13.67±2.13 mm, at the end of diastole in athlete group, differed significantly from control group: 110±14.2 g (p=0.0001) and 8±0.9 mm, respectively (p=0.0001). The same happened to the thickness at the end of systole, which was 18.87±3.40 mm (control group: 10±1.80 mm, p=0.0001). CONCLUSION: Results allowed for concluding that LVH in marathoners in full sportive activity period, assessed by non-invasive methods, represents an adaptative response to intensive and prolonged physical training, with purely physiological characteristics.
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