ABC | Volume 111, Nº6, December 2018

Original Article Silva et al Cardiac and vascular features in athletes Arq Bras Cardiol. 2018; 111(6):772-781 damage in the long run. In this regard, impaired vascular function has been demonstrated in strength athletes, though it appears to be related to the use of anabolic agents rather than an effect of training. 33,34 Heffernan et al. found increased forearm reactive hyperemia in healthy young individuals after 6-month strength training. 35 The most likely explanation for increased endothelium-dependent dilation in strength training is the assumption of the mechanical compression of resistance vessel walls during exercise, followed by blood flow release after cessation of exercise, producing a sharp increase in vessel wall shear stress. 36 Although training modalities involve different stimuli (running training: increased continuous blood flow; strength training: intermittent compression of the muscles and restoring blood flow) they ultimately produce the same effects on vessel wall shear stress. It is important to note that, despite increased blood pressure levels and greater posterior wall thickness and LV mass found in our study among powerlifters, they showed no cardiac and endothelial function impairment when compared to runners and all the parameters were above average. Therefore, high blood pressure found in powerlifters seems to be related to increased PVR rather than endothelial function impairment. Study strengths and limitations The key strengths of our study are the use of a homogeneous sample (within each group) and that all echocardiographic images were assessed by two independent examiners, one of them blinded. However, our data should be interpreted with caution due to some limitations including the small sample size (due to recruitment challenges as anabolic steroid use is common among powerlifters and fewmet our inclusion criteria), and the challenge of recruiting a sample of untrained healthy subjects; however, all parameters evaluated were compared with those findings of other studies and/or current guidelines. Conclusion Our study showed that cardiac remodeling seems dependent on training modalities and not on structural difference, as in BSA-indexed LV mass in both powerlifters and long-distance runners. Systolic and diastolic functions were preserved in both modalities. Powerlifters showed higher resting blood pressure, which can be explained by increased PVR. However, FMD measurements were similar in both groups studied and were well above average. Although our findings are comparative in nature and derive from a cross-sectional design, it is possible to speculate that high-intensity strength training for a significant number of years (~5 years or more) may be associated to borderline structural cardiac changes, though they are not accompanied by reduced cardiac function. Author contributions Conception and design of the research: Silva DV, Lehnen AM; Acquisition of data, Analysis and interpretation of the data, Statistical analysis and Writing of the manuscript: Silva DV, Waclawovsky G, Kramer AB, Stein C, Eibel B, Grezzana GB, Schaun MI, Lehnen AM; Obtaining financing: Waclawovsky G, Lehnen AM; Critical revision of the manuscript for intellectual content: Waclawovsky G, Eibel B, Grezzana GB, Schaun MI, Lehnen AM. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding There were no external funding sources for this study. Study Association This article is part of the thesis of master submitted Diego Vidaletti Silva, from Instituto de Cardiologia - Fundação Universitária de Cardiologia (IC/FUC). Ethics approval and consent to participate This study was approved by the Ethics Committee of the Instituto de Cardiologia do RS / Fundação Universitária de Cardiologia under the protocol number #417492. All the procedures in this study were in accordance with the 1975 Helsinki Declaration, updated in 2013. Informed consent was obtained from all participants included in the study. 1. MaronBJ,PellicciaA.Theheartoftrainedathletes:cardiacremodelingandthe risks of sports, including sudden death. Circulation. 2006;114(15):1633-44. 2. McCann GP, Muir DF, Hillis WS. Athletic left ventricular hypertrophy: long- term studies are required. Eur Heart J.2000;21(5):351-3. 3. GotoC, Nishioka K, Umemura T, Jitsuiki D, Sakagutchi A, KawamuraM, et al. 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