April 22, 2017 Abraham Rothman, MD

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1 April 22, 2017 Abraham Rothman, MD University of Nevada School of Medicine

2 } Definitions } Adults } Children } Heart beats

4 } Children and adolescents who want to participate in intensive exercise. } Just as there is too much exercise for skeletal muscles and bones, it is intuitive that there should be a limit to cardiac muscle exercise / function } What is that limit? } What is the evidence?

5 } 490 BC: Phidippides, young Greek messenger } Ran 26.2 miles from Marathon to Athens } Delivered the news of the Greek victory over the Persians } Immediately collapsed and died. } 1984: Jim Fixx, author of The Complete Book of Running (1977), collapsed and died while running. }? Adverse effects of exercise on the heart?

6 } Webster: physical activity that is done in order to become stronger and healthier. } Wikipedia: any bodily activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons, including strengthening muscles and the cardiovascular system, honing athletic skills, weight loss or maintenance, and merely enjoyment.

7 }??? } Very individual } In each person, varies at different stages of life } Starting an exercise program, versus continuing or advancing

8 Aerobic - dynamic, endurance Anaerobic - static, strength Flexibility - stretching Aerobic decrease in diastolic blood pressure Anaerobic increase in systolic blood pressure during exercise

9 n Both aerobic and anaerobic exercise work to increase the mechanical efficiency of the heart by increasing cardiac volume (aerobic exercise), or myocardial thickness (strength training). n Ventricular hypertrophy, the thickening of the ventricular walls, is generally beneficial and healthy if it occurs in response to exercise

11 There is a dose-response relation between the amount of exercise performed from approximately 700 to 2000 kcal of energy expenditure per week and allcause mortality and cardiovascular disease mortality in middle-aged and elderly populations. The greatest potential for reduced mortality is in the sedentary who become moderately active.

12 } National Cancer Institute, Harvard + other institutions. JAMA 2015 } 6 large studies, >661,000 adults, most middle-aged. 14 year F/U. } Exercise recommendation = 150 min moderate exercise/week: } Range: 0 to 10 X the current rec or more (> 25 hours/wk) } No exercise: highest risk of early death. } Exercised a little, not meeting rec, decreased death by 20 percent. } Met the guidelines precisely, 31 percent less risk } Sweet spot: 3X recommended, one hour + / day = 39 % less risk. } 3X to > 10X recommended = no added benefit. But no increased risk.

13 } Australian adults: > 200,000. light and strenuous exercise. JAMA 2015 } Met exercise guidelines - reduced the risk of early death. } Occasional vigorous exercise, gained a small additional reduction in mortality. If up to 30 percent of weekly exercise vigorous = 9 percent less likely to die prematurely than people at moderate exercise level. If >30 percent of exercise time in strenuous activities = extra 13 percent reduction in early mortality. } No increase in mortality, even in the largest amounts of intense exercise. } Recommend: try to reach at least 150 minutes of physical activity per week and have around 20 to 30 minutes of that be vigorous activity,

14 } Armstrong et al. Circulation 2015 } UK, 1.3 million women, ages 50-64, followed for 9 years. Risk of CHD, stroke, VTE } Highest risk: no exercise } Moderate exercise: 3X/week, lowest risk } Daily exercise, no further decrease in risk, perhaps a slight increase in risk } BEST: moderate exercise

16 } Sudden death } Cardiac enlargement } Transient biventricular systolic and diastolic dysfunction } Hypertrophy } Acute increase in troponin } Fibrosis } Arrhythmias atrial fibrillation

17 } London marathon: , 7 deaths: 5 due to coronary disease, 2 hypertrophic cardiomyopathy } Frere et al Among 1,636,720 marathon participants, 5 deaths, all with coronary artery disease } Death in subjects with normal hearts exceedingly rare

18 } Risgaard et al Heart Rhythm 2014 } 3 year study, ages years old } Sudden cardiac deaths in the country reviewed per 100,000 person years } SCD in general population: 10.7 } Sports related SCD - non-competitive athletes: 0.43 } Sports related SCD competitive athletes: 0.47

20 }? Eccentric hypertrophy } Fibrosis } Up to 1/3 of sudden cardiac death events in athletes have no pathologic/clinical explanation (no coronary issues, no undue hypertrophy or fibrosis, no channelopathies) } In isolated cases, athlete s heart and inherited disease may not be mutually exclusive

21 } Tour de France cyclists live 8 years longer than general population } Finnish national athletes live 4 years longer than military recruits of that country }? Ideal control groups

25 } Oxborough et al 2011 Circ Cardiovasc Imaging 2011 } 16 adults, 161 Km ultramarathon } RV dilatation and RV dysfunction documented }??Effect of repeated bouts of RV dilatation and dysfunction

26 } Cardiac outputs of > 40 L/min documented in some elite athletes } Atrial enlargement } Increased A Fib fold in endurance athletes } Baldesberger et al. nonsustained VT in retired professional cyclists 15% vs retired golfers 3% } Heidbuchel et al. exercise-induced RV cardiomyopathy in ex-endurance athletes presenting with symptoms

27 } Marathon runners over 50 years old had a 5 fold increase in the incidence of A Fib, compared to controls.

28 } MRI - delayed gadolinium enhancement (DGE) } DGE patches observed in 12-50% of intensively trained athletes in one study }??? Clinical significance } Two other studies: no higher incidence than controls } Some have shown that if pre-existing coronary disease, intensive exercise may increase myocardial fibrosis, despite improved coronary vasodilatory capacity with exercise

30 } Benito et al. circulation 2011 } Mice subjected to 12 weeks of aggressive, exhaustive exercise training: } RV enlargement } Diastolic dysfunction } Fibrosis } Increased susceptibility to triggered VT } BUT: Painful stimuli to make animals exercise, how to compare mice with humans?

31 } La Gerche et al. Heart 2008 } 21 athletes, ultra-endurance triathlon } TnI, and BNP levels before and immediately after race } TnI: Increase from 0.17 to 0.49, increased in 58% of athletes } BNP: Increase in every athlete from 12 to 42 } No change in LV function } Decreased RV systolic function, fractional area change from 0.49 to 0.37 } All abnormalities resolved in 1 week

33 } Neilan et al. Circulation 2006 } 60 non-elite participants, Boston marathon } Echo, ctnt and NT-proBNP levels pre and post-race } 60% had an increase in ctnt to above normal, 40% had levels considered for MI diagnosis } NT-proBNP increased from 63 to 131 } Transient LV diastolic and RV systolic dysfunction } Cardiac dysfunction and injury??

36 } Ayabakan et al Cardiol in the Young 2006 } 22 swimmers, age 11 years, 10 hours/week of strenuous swimming. 21 controls } Followed for 4 years } No change in function } Concentric, rather than eccentric LV hypertrophy

37 } Obert et al. Int J Sports Med 1998 } Fleury-Les-Aubray, France, school, year olds } 9 swimmers, 11 controls } 12 hours per week for at least 2 years of intensive swimming } Swimmers: larger LV diameter, lower resting heart rate, increased stroke volume } No changes in systolic or diastolic function

38 } Hauser M. et al. Pediatr Cardiol 2013 } Munich Triathlon Heart Study } 26 children: ages 8-16 years, age-adapted triathlons. Pre and post race echos } Increase in cardiac output, mostly as a result of increased heart rate. Transient, mild systolic and diastolic right and left ventricular dysfunction. }? Long-term significance

} Unnithan et al. Pediatr Cardiol 2015 } 5 Km cross country race, England } 20 trained adolescent males (age 15.

39 } Unnithan et al. Pediatr Cardiol 2015 } 5 Km cross country race, England } 20 trained adolescent males (age /- 0.7 yrs) } Echocardiograms pre and post race } No significant post race changes in LV systolic or diastolic function

40 } Traiperm et al. AJC 2012 } 37 marathon runners, ages 13-17, Sports school, Thailand } 30 of 37 had an increase in troponin above reference levels (0.01), 3 of 37 had above MI levels (0.1) } All had normal troponin levels at 24 hours } Rapid recovery suggests: physiologic rather than pathologic response.

44 } Hypothesis: Heart has only so many beats in it. Similar to and perhaps connected to the Hayflick limit, most of the cells in our bodies can divide a certain number of times. } Difference in the number of heart beats if fit vs. unfit. Example: a fit person's HR = 55, unfit person's HR = 85, a difference of 30 beats per minute, 1,800 heartbeats per hour, 43,200 beats per day, and more than 15 million heartbeats per year. Over 20 years, the fit person's heart will save approximately 315 million heartbeats over the unfit person. That's about 11 year's worth of heartbeats!

45 } Danish Study: Mortality risk of healthy men increases by 16% for every 10-beat-per-minute increase in resting heart rate, Heart } 5,249 healthy men who were middle aged starting in 1971, collected heart rate and mortality data until } Men with resting heart rates of 71 to 80 beats per minute were 51% more likely to die than men with resting heart rates of 50 beats a minute or less } Men with resting heart rates of 81 to 90 beats per minute were twice as likely to die than those at 50 beats per minute.

46 } Intensive exercise appears to increase your chances of living longer, but may increase the risk of some arrhythmias } Exercise results in a lower baseline heart rate and should result in more years of heart beats } So,

48 } Eating alone will not keep a man well, he must also take exercise } Give every individual the right amount of exercise, not too little and not too much

49 Children s Heart Center Nevada Physicians and staff

Excess exercise 'hurts the heart' and cause dangerous long-term harm, say scientists Mail... Page 1 of 10

Excess exercise 'hurts the heart' and cause dangerous long-term harm, say scientists Mail... Page 1 of 10 Click here to print Excess exercise 'hurts the heart' and cause dangerous long-term harm, say scientists