USAT Medical Multisport Conference

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I had the chance to be a speaker at the November, 2014 USA Triathlon (USAT) Medical Multisport Conference that was held at the Olympic Training Center in Colorado Springs.  The weekend brought 2 days of talks that focused on aspects of sports medicine that were particularly relevant to triathlon and multisport.

Travis Tygart, CEO of the United States Anti-Doping Agency (USADA) was the keynote speaker.  We heard about event and safety planning from a very experienced group of USAT-affiliated physicians, including W. Douglas Hiller, MD, Andrew Hunt, MD, and John M. Martinez, MD.  I gave talks on some of my favorite topics:  “Triathlon Fatalities,” “Endurance Sport:  Is it Heart Healthy?,” and “Cardiovascular Considerations in the Aging Athlete.”  We had lunch with Kathy Matejka, the USAT Event Services Director and dinner with Rob Urbach, CEO of USAT.

I met some terrific folks and I learned a lot.

It was great to visit the Olympic Training Center.  I particularly enjoyed the museum area and a workout at the pool.  The snow and cold weather got the best of a planned group run, though.

This year’s Conference is planned for November 5-7, 2015, again at the Olympic Training Center in Colorado Springs.  This year’s keynote speaker will be Robert Laird, MD, the original and long-time medical director for the Ironman World Championship race in Kona, Hawaii.  This would be a worthwhile meeting for anybody who’s involved with medical care of multisport athletes, including nurses, physicians, and allied health professionals.  Information about the meeting schedule, speakers, and registration can be found at the USAT website.

I hope that you’re able to join us in November!

Triathlon, Open Water Swimming, and the Heart: What Can We Learn From Dolphins and Seals?

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A recent study about marine mammals caught my eye.  I don’t know much about non-human biology and physiology, but this study on dolphins and seals may shed some light on the problem of fatalities during open water swimming or triathlon events.

The Study

A group of investigators headed by Terrie Williams from the University of California at Santa Cruz shared their report, “Exercise at depth alters bradycardia and incidence of cardiac anomalies in deep-diving marine mammals” in the January 16th edition of Nature Communications (1).

This group of investigators has been interested in the physiology of the so-called “dive response” in marine mammals.  This is a response that is governed by the involuntary, or autonomic, nervous system, which has two antagonistic components:  the parasympathetic nervous system and the sympathetic nervous system.  As a group, the marine mammals depend on feeding by chasing pray to depths that can range up to 3,000 m.  Even at lesser depths, these mammals must maintain a breath-hold under large hydrostatic pressures while they undergo extreme exertion to catch their pray.  During a dive, breath-holding stimulates the parasympathetic nervous system to slow the heart rate (producing bradycardia).  At the same time, the exertion required to chase pray stimulates the sympathetic nervous system, producing an increase in the heart rate.  The current study offers the first detailed study of the interplay between the components of the autonomic nervous system during routine diving and feeding activity in these animals.

The investigators created an electrocardiograph-accelerometer depth monitor that was deployed on 10 Atlantic bottle-nosed dolphins and 3 Weddell seals.  This device allowed high-fidelity recording of the heart rate, ECG, water depth, and swimming stroke frequency (a measure of exertion) during dives.  For the dolphins, measurements were made for 74 dives to depths of up to 210 m.  For the seals, measurements were made for 91 dives to depths of up to 390 m.

The Results

As expected, there was a strong relationship between diving depth and heart rate for both species, with heart rates falling during descent and reaching a minimum at the lowest depth of the dive.  Superimposed on this effect was an additional effect of exertion.  For the dolphins, the maximum heart rate was 1.7 to 3.7 times greater during periods of extreme exercise compared to gliding alone.  For the seals, the maximum heart rate was 1.5 to 1.8 times greater during periods of extreme exercise compared to gliding alone.

The surprising finding was that cardiac arrhythmias occurred in more than 73% of the dives.  The investigators defined arrhythmias to include ectopic beats or significantly increased variability in the interbeat interval (IBI).  There were apparently no sustained or fatal arrhythmias., but there were discrete examples of “wandering pacemaker” and ventricular premature beats.  In the Weddell seals, there were often patterns of alternating periods of tachycardia (fast heart rate) and bradycardia (low heart rate) during periods of constant, intense exertion.

The presence of cardiac arrhythmias was strongly correlated with increased depth of dive (parasympathetic activation) and increased exertion (sympathetic activation).  As an example, cardiac arrhythmias occurred in 81% of the dolphin dives to >210 m but in only 26% of dives to <100 m.

The authors concluded that our previous understanding of the dive reflex in marine mammals was not totally correct.  Given that these animals depend on diving for their food sources, the development of cardiac arrhythmias during feeding appears to be mal-adaptive.  In fact, feeding might actually be dangerous.

My Thoughts

At first glance, the physiology of the diving response of dolphins and seals during feeding seems far afield from open water swimming and triathlon.  And moreover, we already know about the development of cardiac arrhythmias during submersion in breath-holding humans as well as other marine species.  The important observation here, though, is what I might call “irritability” or “instability” in the heart rhythm during periods of intense parasympathetic and intense sympathetic activation….and that’s the possible link to human fatalities during open water swimming or triathlon.

We know from autopsy reports of triathletes who’ve died during the swim portion of an event that there are sometimes only subtle abnormalities of the heart, and often nothing that seems explanatory.  That leaves us in a difficult position to explain such deaths.  In a previous blog post, I wrote about one very plausible hypothesis. Two UK physiologist,s X and X, proposed the concept of “autonomic conflict,” where a surge in both the parasympathetic and sympathetic stimulation of the heart might lead to a fatal arrhythmia.  I’ve been intrigued with this hypothesis because it seems to fit many of the observations made about the swim victims.  It is easy to see where exertion, cold water, anxiety, etc. might lead to strong sympathetic activation.  And it’s equally easy to see where facial wetting, water entering the mouth/hypopharynx/nasopharynx, and breath-holding, even without diving, might lead to strong parasympathetic activation.  In that instant, in an athlete with some sort of susceptible heart, a fatal arrhythmia might occur.

The new observations about the dolphins and seals seem to play into this hypothesis.

 

Related Posts:

1. Fatalities in Open Water Swimming:  What’s the Mechanism?

2. Triathlon Fatalities:  2013 in Review

 

Reference:

1.  Williams TM, Fuirman LA, Kendall T, et al.  Exercise at depth alters bradycardia and incidence of cardiac anomalies in deep-diving marine mammals.  Nature Communications 2015;6:6055.

 

 

 

Book Review: Heart to Start

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Check out the newly published “Heart to Start:  The Eight Week Exercise Prescription to Live Longer, Beat Heart Disease, and Run Your Best Race,” by cardiologist, James Beckerman, M.D.  The book is available at Amazon and other outlets.

This is a terrific book!

First, let me share a little bit about the author.  Dr. Beckerman is the Medical Director of the Center for Prevention and Wellness at the Providence Heart and Vascular Institute in Portland, Oregon.  He is also the team cardiologist for the Portland Timbers Major League Soccer team and the founder and medical director for Portland’s Play Smart Youth Heart Screenings.  He is passionate about wellness, exercise, and preventive cardiology.  Follow him on Twitter at @jamesbeckerman.

Perhaps you’ve had a heart attack and your doctor has recommended exercise.

Perhaps you’ve discovered that your blood pressure or cholesterol is elevated and your doctor has suggested exercise as a treatment.

Perhaps you’ve just decided to get up off the couch and be more active.

The inevitable question is, “How do I get started?”  This book is for you!  In Dr. Beckerman’s words, “This is a book about exercise and I guarantee that it will move you….”.  More coach than doctor, he will guide you every step of the way as you get going.  Take him up on the offer.

This book starts with a very personal and riveting Foreword by Dave Watkins.  He asks, “What is your legacy?”  He shares his near-death experience with urgent heart surgery for a diseased heart valve and aortic aneurysm on the verge of rupture.  There were certainly ups and downs during Dave’s recovery, but he survived and then some!  Read about Dave’s return to exercise, his successes in triathlon, and the founding of his Ironheart Foundation.  Dave’s story will provide ample motivation.

The book is divided into 3 sections….

Warm Up.  In the first section, Dr. Beckerman helps you to take stock of your health in general and your heart in particular.  He introduces the concept of preventive cardiology and illustrates this with real-world examples where “an ounce of prevention is worth a pound of cure.”  Dr. Beckerman shows you how to use the Sit Rise Test and the 6-minute walk test to size up your fitness level.  This section concludes with a discussion of how traditional cardiac rehab and structured exercise can be so valuable.

Workout.  In the second section, Dr. Beckerman lays out what he calls your “Heart to Start Exercise Prescription.”  You’ll start with an assessment of your VO2max, an index of your aerobic capacity or fitness, and then embark on an 8-week exercise program that is tailored to your fitness level.  There are both HEART (aerobic exercise) and START (strength exercise) components.  The program is structured but simple.

Cool Down.  In the final section, Dr. Beckerman sums things up.  He recognizes that there are always choices and asks you to remember to consider, “What would a healthy person do?”  For those wishing to continue on, he leaves you with a 12-week exercise program that will get you to the start line of a 5K running race.  It’s a program that he uses in Portland with his popular Heart to Start group (see the photo).  You can be sure that the program works.

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This book is for….

If you’re ready to get going, take a copy of “Heart to Start” to your next doctor’s visit and talk about getting started.  Team up with your doctor to put Dr. Beckerman’s exercise prescription to work for you.

For many readers here at the blog, exercise may already be an important part of your routine.  But I bet you know others, perhaps in your own family, who haven’t yet embraced exercise.  Get them a copy of the book and help them get started.

Perhaps you’re in a position to organize a group exercise program like Dr. Beckerman’s Heart to Start program.  I bet he’d be happy to hear from you and help you get things organized.

 

Related Posts (Other Book Reviews):

1. Cardiac Athletes, by Lars Andrews

2.  The Exercise Cure, by Jordan Metzl, MD

 

In the News: Cardiac Screening for Adult Recreational Athletes

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An important new study caught my eye.  In last week’s British Journal of Sports Medicine, Andrea Menafoglio and her colleagues from Bellinzona, Switzerland published (epublished ahead of print) a report entitled, “Cardiovascular evaluation of middle-aged individuals engaged in high-intensity sport activities:  implications for workload, yield and economic costs.”(1)

The study is important because it addresses the issue of cardiovascular screening in adult, recreational athletes, an area that’s received very little attention.

By comparison, the issue of cardiac screening for young, competitive athletes has received a great deal of attention over the past 25 years.  Many prominent medical scientific organizations have issued recommendations for pre-participation screening in young athletes, including the American Heart Association (1), American College of Cardiology (ACC), American Academy of Family Practice (AAFP), American Academy of Pediatrics (AAP), American College of Sports Medicine (ACSM), American Medical Society for Sports Medicine (AMSSM), just to name some of the American organizations.

These recommendations form the basis for the widespread use of mandatory pre-participation screening in secondary schools and colleges. The goal of such screening programs is to reduce the number of fatalities from sudden cardiac problems that arise during sporting activities.   The successes and pitfalls of such screening programs have been reported and the findings have engendered lively debate about what elements to include in screening programs, their effectiveness, and justification of their cost.

In this new study, the investigators report on a “real world” glimpse into cardiovascular screening in adult, recreational athletes.  Their aims were to evaluate the practicality of such a screening program, to measure the prevalence of previously unrecognized cardiovascular conditions in this group, and to determine the costs associated with initial screening and follow-up evaluation of athletes with an abnormal initial evaluation.

 

The Study

The investigators enrolled 785 athletes, aged 35-65 years (mean, 46.8 years), who engaged in “high-intensity sports” for at least 2 hours per week.  The athletes’ sports included running (in 33%) and cycling (in 24%), among others.  The majority of subjects (73%) were male.  The athletes were primarily “amateur” (69.7), but the group included some who competed in regional (23.7%), national (4.6%), or international competition (2.0%).

Athletes with a known history of cardiovascular disease, except for treated high blood pressure, as well as athletes who had previously undergone cardiac screening within the previous year were excluded.

Each athlete underwent a cardiac screening evaluation according to the current guidelines established by the European Association of Cardiovascular Prevention and Rehabilitation (EACPR).  The evaluation was free to each athlete and included:

  • Thorough personal and family medical history
  • Physical examination
  • ECG
  • Estimation of the individual’s cardiovascular risk using the Systemic Coronary Risk Evaluation (SCORE) chart for Switzerland
  • Blood testing for total cholesterol and serum glucose.

The SCORE chart was used to estimate the athlete’s 10-year risk of death due to atherosclerotic heart disease based on gender, age, total cholesterol level, systolic blood pressure, and smoking status.  Athletes were deemed at “high risk” if their predicted risk was >5% or if any single risk factor (eg, total cholesterol, blood pressure) was markedly abnormal.  The cost of this screening evaluation was reported to be $130 per athlete, or $102,050 total.

 

The Findings

The screening evaluation was abnormal in 112 athletes (14.3% of the total):

  • 5.1% due to abnormal, “pathologic” ECG findings
  • 4.7% because of abnormal physical examination
  • 1.6% due to a “positive” personal or family medical history
  • 4.1% because an athlete was at “high risk” for atherosclerotic heart disease

Each of these athletes then underwent subsequent, more detailed testing to shed more light on the athlete’s cardiac circumstance and to determine if a true cardiac problem was present.  These tests included, among others:  echocardiogram (an ultrasound examination of the heart’s structure and function); stress test; 24-hour blood pressure monitoring; 24-hour Holter monitoring (of the ECG, continuously, to evaluate for arrhythmias); cardiac MRI; coronary angiography; and tilt testing.  A total of 194 such tests were performed and these additional tests had a total cost of $54,556.

In the end, a new, previously unsuspected cardiovascular problem was identified in 22 (or 2.8% of the 785) athletes:

  • 8 with hypertension
  • 5 with mitral valve prolapse and at least moderate mitral regurgitation
  • 3 with biscuspid aortic valve (2 with moderate aortic regurgitation and 1 with mild aortic stenosis)
  • 1 with mild pulmonary valve stenosis
  • 1 with vaso-vagal syncope
  • 1 with Wolf-Parkinson-White syndrome
  • 1 with hypertrophic cardiomyopathy (HCM)*
  • 1 with significant coronary artery disease and “old” myocardial infarction*
  • 1 with abdominal aortic aneurysm*

This group included 19 men and 3 women.  Of these 22 athletes with newly diagnosed cardiac conditions, 3 were deemed ineligible to participate in their sports because of unacceptably high risk of cardiovascular events (indicated by an asterisk, above).  Each of the 3 athletes who were deemed ineligible for sports activities were identified by an abnormal ECG during the initial screening.

The other 90 athletes with an abnormal initial screening evaluation were “cleared” on the basis of their subsequent testing.  We might refer to these athletes as the “false-positives”–those with an abnormal initial screening evaluation, but no real cardiovascular problem.

Interestingly, no diagnosis of coronary artery disease (CAD) resulted from the 76 exercise stress tests that were performed.

 

The Investigators’ Conclusions

The authors reached 4 main conclusions:

  1. The screening program was effective in identifying a small, but significant, number of athletes with significant cardiovascular conditions that required treatment or monitoring.
  2. The screening program was effective in identifying a very small number of athletes in whom continued participation in sports activities was thought to be dangerous.
  3. Inclusion of the ECG in the initial screening evaluation was important.
  4. The screening program was practical and the costs were reasonable.

 

My Thoughts

This study provides some pertinent data to help frame our discussions about cardiovascular screening for adult, recreational athletes.  The study population here appears to be typical in many regards, and I suspect the study results can reasonably be generalized to athletic populations far beyond Switzerland.

Adult, recreational athletes are not typically bound by the mandatory pre-participation cardiac screening programs that are used for young, competitive athletes.  They have to make their own decisions in this regard.  They must decide whether “getting checked out” is worth the expense.  Athletes might have a variety of relevant questions.  How likely am I to discover a previously unrecognized cardiac problem–particularly if I don’t have any symptoms?  What are the chances that I could be a false-positive–with the burden of additional diagnostic testing to sort things out?  What will this all cost?

Each of these questions now has an answer.

With regard to the first question, there is an approximately 3% chance of identifying a previously unrecognized, unsuspected, and presumably asymptomatic, cardiovascular condition.  On t op of that, there is an approximately 4% chance of identifying a high risk profile, based on risk factors, that deserves close follow-up.  And finally, there is an approximately 0.4% chance (3 athletes among 785) of identifying a serious cardiovascular condition that places an athlete at undue risk of sudden cardiac death during exercise.  It’s not clear from the study whether these risks are similar for men and women.

The second question also has an answer.  The chance of a false-positive, using this particular screening evaluation, was approximately 11.5% (90 athletes among 785).  That is a fairly large number.  Recall that each of these athletes required additional diagnostic testing–at additional cost–to establish that they didn’t actually have a problem after all.

The third question has also been answered–at least in Switzerland.  The average cost of the screening program–initial evaluation plus the costs of additional testing that was needed–was $199 per athlete.  The cost for the 663 athletes who had a normal screening evaluation was only $130.  Obviously, the costs for the remaining 122 athletes, with an abnormal screening evaluation, and who required additional diagnostic testing, were greater.  All of these costs would be much higher in the United States, I suspect, and this issue is compounded by the fact that most health insurance policies don’t cover screening evaluations such as these.  For many American athletes, these expenses would be out-of-pocket.

At any rate, this new information will be helpful as athletes have discussions with their physicians about whether or not to pursue cardiac screening.

Those are my thoughts about the issue from the athlete perspective.

From the physician perspective, I think it’s important to note that all of the stress testing results were normal.  These are expensive tests.  We need to keep in mind that the pre-test probability of an abnormal finding in an asymptomatic population of exercisers is extraordinarily low.  Perhaps, it’s best to think twice before ordering a stress test in this situation.

And finally, from the perspective of the event organizer, the prevalence data here is enlightening.  Governing bodies and race directors should be aware that several percent of participating athletes will have unsuspected cardiovascular problems, including 0.4% who are at high risk of sudden cardiac death during exercise.  These numbers should inform safety planning efforts.  It shouldn’t be surprising that we have a small number of cardiac emergencies and even fatalities in recreational competitions involving adult athletes.

 

Reference:

1.  Menafoglio A, Di Valentino M, Porretta AP, et al.  Cardiovascular evaluation of middle-aged individuals engaged in high-intensity sport activities:  implications for workload, yield and economic costs.  Br J Sports Med 2014;01-6.  doi:10.1136/bjsports-2014-093857.

Mixed Emotions About The Medical Tent

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I’m fascinated by the medical tent at endurance sporting events.  Maybe that’s not surprising.  After all, I’m a doctor and an athlete.

I have mixed emotions about the medical tent, though.  Maybe you do, too.  Let me explain….

Dr. Laird and the Kona Medical Tent

I got to thinking about the medical tent this past month when I listened to a talk given by Dr. Robert Laird, the long-time (now retired) medical director for the Ironman World Championship race in Kona.  He gave a talk at a sports medicine symposium held in conjunction with this summer’s Challenge Atlantic City events.  He told the ~23-year history of medical support for the Ironman race, beginning with its first year in Kona in 1981.  That year, Dr. Laird stood on the pier watching the swimmers, dressed in running gear, stethoscope around his neck, cap on his head….and he alone was the extent of the medical support.

Of course, today it’s much different.  On race day, there is a 50- to 60-bed field hospital set up in a tented area across from the Kailua Pier.  It’s arranged in pods of 6 patient beds and staffed with many physicians, nurses, physical therapists, and non-medical volunteers as well.  On race day, it’s the 3rd largest “hospital” on the Big Island of Hawaii.  And on race day, up to several hundred athletes among the nearly 2,000 participants in the race receive medical care there.

The medical support team also has a fleet of makeshift “ambulances”–rented white vans with a temporary red cross affixed to the side.  Without these vehicles, the need to respond to athletes on the 112-mile bike course or 26.2-mile run course would overwhelm the resources of the local EMS system.

If you’re an athlete with medical needs on race day, the setup is awesome.  In truth, the Ironman event as we know it today would be impossible to stage without this elaborate medical support.

My Own Medical Tent Memories

Thankfully, I’ve avoided the medical tent as a patient.  I did take a break at a medical aid station along the run course at the 2012 Ironman New Zealand race when I was feeling poorly.  But after a cool refreshment, some much needed shade, and a short break, I was able to continue along my way.

I’ve waited near the doors of the medical tent on a couple occasions, though, while my athlete friends were receiving treatment.  I remember my buddy, George, losing 12 pounds during the Ironman New Zealand race in 2007 and needing rehydration.  I also recall my friend, John Pendergrast, an ophthalmologist, needing treatment for a couple hours after finishing the Ironman South Africa race.  Our small group of traveling partners waited anxiously to be sure that John was okay.

I volunteered once in a major medical tent–for the Ironman Florida race.  I worked the 6 pm to midnight shift.  My lasting memory will be of the athletes who arrived at the finish line and then collapsed.  On a day with high temperatures in the gentle 70’s I was surprised at how many athletes arrived at the medical tent at the finish line severely hypothermic and dehydrated.  It seemed that the athletes who were worst off were those who arrived after finishing the race in 10-11 hours or so.  Perhaps the later arrivals had gone too slowly to get “messed up.”  We treated a bunch of athletes that night.

I’ve enjoyed reading the accounts of others who’ve worked in the triathlon medical tent.  Check out the report by professional triathlete and physician, Tamsin Lewis.

Marathon Medical Tents

Of course, the medical tent today isn’t confined to triathlon.  There is elaborate medical safety planning for the major running races, too.  There is often a medical tent at the finish line of the big city marathons and these are often staffed, at least in part, by volunteers.

I recently attended a lunchtime lecture given by one of my cardiology colleagues who had volunteered at the medical tent for the Boston Marathon.  There’s a sports medicine symposium before the race and the attendees are offered the opportunity to volunteer in the medical tent.  This gives physicians a chance to put into practice what they’ve just learned.  Listening to his tale, I get the impression that virtually any medical problem can manifest during the marathon, but that dehydration and heat-related illnesses are the common medical ailments.  He shared (and I’ve heard from others as well) that ice baths for rapid cooling of victims with severe heat-related illness probably make the difference for survival–that the EMS system and local hospital emergency rooms might not have the available resources to get athlete patients cooled so quickly.  That’s an eye-opener.

Malpractice Insurance Issues

I’ve often wondered–and even worried–about the issue of malpractice insurance coverage for physician volunteers at medical tents.  It’s one thing if you’re an emergency physician or sports medicine physician.  But it’s another situation entirely if you’re volunteering in a capacity outside your specialty–and perhaps outside the state where you’re licensed.  The issue would seem to be relevant not only to physicians but also to nurses and other licensed healthcare professionals as well.

It would be interesting to know if there are instances of malpractice lawsuits brought by athlete-patients against medical tent volunteers.  I’m told by the folks at USA Triathlon (USAT) that they’re not (yet) aware of any instances.

In order to encourage volunteer participation by medical professionals at triathlon medical tents, USAT has organized a malpractice insurance coverage opportunity.  This opportunity hasn’t received much publicity.  For a very modest premium, any licensed medical professional can obtain insurance coverage in situations where their own policies wouldn’t be applicable.  I bet this would help put some potential volunteers’ minds at ease and encourage their involvement.

The Mixed Emotions

So, back to the mixed emotions.  No doubt, the medical tents at triathlon and major running events provide a useful and needed service.  In some cases, it would be impossible to hold events without an organized medical safety net that includes an on-site medical tent.  And no doubt, countless athletes have benefitted from care they’ve received by volunteers at these medical tents.  So, in the sense of providing a safety net for participants, the medical tent is great.

But on the other hand, I have to wonder if the very existence of the medical tent and ready availability of volunteer medical care doesn’t encourage unsafe behavior on the part of athletes or event organizers.  I also wonder how outsiders view this whole enterprise.  Surely, if intravenous hydration is required by large numbers of participants just to complete an event, there must be something wrong–either in the venue, the weather conditions, or the preparation of the athletes.  Yet I hear many athletes talk casually about how they’ll “just get an IV” after the race.

At any rate, this is all food for thought.  I’m intrigued by the medical tent.  I hope it’s there when I need it, staffed by capable healthcare professionals.  I’ll probably volunteer again, too.  But I’ll also have some nagging worries.