IJCS | Volume 31, Nº3, May/ June 2018

DOI: 10.5935/2359-4802.20180012 Introduction Since the 19 th century, cardiac adaptations induced by physical exercise have been known. Henschen, in 1899, recognized cardiomegaly in long distance skiers through percussion of heart borders, concluding that this increase was related to cavity dilatation and wall hypertrophy of the left ventricle (LV), and that these changes resulted in physical benefits for the athletes. 1,2 With the evolution of complementary diagnostic means, mainly echocardiography, Morganroth et al., 3 in 1975, developed the hypothesis that cardiac morphological changes depended on hemodynamic overload associated with physical exercise: dynamic exercise associated with eccentric hypertrophy due to volume overload, resulting in increased cardiac cavities by serial sarcomere addition; and static exercise associated with concentric hypertrophy due to pressure overload, with LV wall hypertrophy and parallel sarcomere addition. 3-5 209 ORIGINAL ARTICLE International Journal of Cardiovascular Sciences. 2018;31(3)209-217 Additional Cardiac Remodeling Induced by Intense Military Training in Competitive Athletes Paulo Dinis 1,2 , Hélder Dores 3 , RogérioTeixeira 1,4 , Luís Moreno 2 , Joselito Mónico 2 , Marie Bergman 5 , Hanna Lekedal 5 , Maria Carmo Cachulo 1 , Joaquim Cardoso 2 , Lino Gonçalves 1,4 Serviço de Cardiologia, Centro Hospitalar e Universitário de Coimbra 1 , Coimbra - Portugal; Centro de Saúde Militar de Coimbra 2 , Coimbra, Portugal; Hospital das Forças Armadas 3 , Lisboa - Portugal; Faculdade de Medicina Universidade de Coimbra 4 , Coimbra - Portugal; University of Linköping 5 - Sweden Manuscript received on May 10, 2017; manuscript revised on August 25, 2017 accepted on September 22, 2017. Mailing Address: Paulo Dinis Centro Hospitalar de Coimbra Quinta dos Vales - 3041-801 São Martinho do Bispo, Coimbra - Portugal E-mail: paulogdinis@gmail.com , dinis17@hotmail.com Abstract Background: Cardiac remodeling depends on the intensity, duration, and training method. Objective: To evaluate if the training performed in a Portuguese military special operations troop increases cardiac remodeling in a sample of young individuals who previously practiced competitive sports. Methods: A prospective study involving 76 military candidates for military special operations, 45 of whom previously practiced at competitive level (> 10 hours per week). Of these military athletes, only 17 successfully completed the course. The evaluation was performed at 6 months intervals and included a complete clinical history, physical examination, vital signs, anthropometric data and echocardiographic evaluation. Statistical significance was considered when p < 0.05, with a 95% confidence interval. Results: At the end of the course, there was a decrease in the percentage of fat mass (19.1 ± 3.3% vs. 13.1 ± 3.5%; p < 0.01), an increase in the percentage of lean mass (41.3 ± 2.1% vs. 44.4 ± 1.8%; p < 0.01), and decreased systolic and diastolic blood pressure and heart rate. Regarding cardiac remodeling, there was an increase in left ventricular diastolic diameter (49.7 ± 3.2 mm vs. 52.8 ± 3.4 mm; p < 0.01), an increase trend in left atrial volume (27.3 ± 4.5 mL/ m 2 vs. 28.2 ± 4.1 mL/m 2 ; p = 0.07) and increased left ventricular mass (93.1 ± 7.7 g/m 2 vs. 100.2 ± 11.4 g/m 2 ; p < 0.01). Functional variables also changed, with an increase in S’ (15 (13-16) cm/s vs. 17 (16-18) cm/s; p < 0,01) and a decrease in left ventricular ejection fraction (60 ± 6% vs. 54 ± 6%; p < 0.01). Conclusion: Intense military physical training resulted in additional cardiac remodeling in athletes of competitive level, both structural and functional. (International Journal of Cardiovascular Sciences. 2018;31(3)209-217) Keywords: Atrial Remodeling; Exercise; Athletes; Military Personnel.