![]() ![]() 6,9,10ĭynamic exercise produces a volume load to the left ventricle, while static exercise produces a pressure load to the left ventricle. 9,10 The athlete responds to the increased afterload by increasing his or her heart rate. 6-8 In static exercise, intense muscle contractions cause mechanical constriction of arteries which leads to compensatory increases in the arterial blood pressure, and in turn, the afterload. 6-8 Sympathetic stimulation causes increased contractility which leads to a decreased end-systolic volume, resulting in a significantly increased stroke volume. In dynamic exercise, the athlete's left ventricle quickly relaxes and fills to a larger end-diastolic volume. 6Ĭardiovascular Hemodynamics During Sports ParticipationĮndurance (isotonic or dynamic) exercise and strength (isometric or static) exercise result indifferent cardiovascular hemodynamics and produce different loading conditions for the left ventricle. 6 Most competitive sports require both exercise components at different intensity levels. 5 All competitive sports are classified on the basis of two exercise components: endurance (the relative intensity of dynamic exercise, numerically described as the percentage of maximal aerobic power) and strength (the relative intensity of static muscle contractions, numerically described as the percentage of maximal voluntary contraction). In this Expert Analysis, we will review key cardiovascular hemodynamics during sports participation, the causes of sudden cardiac arrest (SCA) during sports participation in competitive athletes younger than 35-years-old, and the current practice guidelines for the evaluation of competitive athletes for sports participation.Ī competitive athlete is an individual who participates in an organized team or individual sport that requires regular competition against others, places a high premium on excellence and achievement, and requires systematic and usually intense training. 3 Likewise, a recent consensus statement on college student-athletes emphasized the importance of the pre-participation history and physical, emergency action plans, and further research on ECG screening. 3 However, the Committee states that there is insufficient evidence to mandate any specific screening test for elite athletes. The International Olympic Committee Medical Commission recommends that the pre-participation evaluation of elite athletes include a medical history, a physical examination, and a 12-lead electrocardiogram (ECG). This August, more than 10,500 elite athletes will travel to Brazil and compete in the 2016 Summer Olympics. 1 Indeed, the incidence of SCD in National Collegiate Athletic Association (NCAA) athletes may be higher than previously thought. 1 Despite the higher risk of SCD in the general non-athlete population, SCD among athletes garners intense scrutiny by the media and represents an emotionally charged medical topic. 1 The estimated incidence of SCD among athletes versus non-athletes was found to be 0.44 per 100,000 person-years, and 13 per 100,000 person-years, respectively. ![]() In the United States, there are approximately 100 to 150 sudden cardiac deaths (SCD) during competitive sports each year. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |