Book Review: Haywire Heart

 

 

 

 

 

 

 

 

Check out the recently published “The Haywire Heart” by Chris Case, John Mandrola, MD, and Lennard Zinn.  The book is available at Amazon and other outlets.

You may recall that Case, Mandrola, and Zinn authored an article in VeloNews, entitled “Cycling to Extremes:  Are endurance athletes hurting their hearts by repeatedly pushing beyond what is normal?”  This was a terrific read.  I wrote a previous blog post sharing my thoughts about the article and about the issue of arrhythmias and endurance sport, more generally.  Their article generated much discussion in the cycling and broader endurance sports communities and the interest of readers served as the motivation for their new book.

This is a book about electrical problems in the heart–the various arrhythmias.  Case, Mandrola, and Zinn are in a unique position to bring this topic to life because each has dealt personally with some form of arrhythmia.  And as long time cyclists (and perhaps with some triathlon experience as well), they’re able fashion the discussion to the avid endurance athlete.  From the medical perspective, the field of arrhythmias is rather complicated, both in terms of the underlying mechanisms of disease and the evaluation and treatment of affected patients, but here the authors have found a writing style that is captivating and accessible to the non-medical reader, while retaining much medical detail that will be of interest.  I give them credit because this is hard to do!

I love the title.  With an arrhythmia, the heart is truly “haywire.”  Ignore the line on the cover, though, about “How too much exercise can kill you.”  That’s unlikely to happen and there’s little in the book about that particular issue.  Instead, focus on “what you can do to protect your heart.”  That’s where the value lies here.

The book is organized into 9 chapters.  In Chapters 1-3, the authors describe in detail how the normal heart works, outline how the heart adapts over time to endurance exercise, and introduce the medical aspects of heart attack and arrhythmias, especially for the endurance athlete.  These sections are well-illustrated and are a great primer for any athlete interested in learning more about the heart.

Chapters 4-6 focus on the evidence of a link between long-time endurance exercise and arrhythmias, what to look for in yourself, and what it’s like to receive the diagnosis of an arrhythmia.  Here, the authors speak from personal experience and their observations and advice are valuable.

Chapter 7 deals with the issue of exercise addiction.  We know that exercise is generally healthy, but most of the benefits of exercise accrue with the first few hours per week.  Why, then, do athletes exercise more?  When does one become addicted?  What are the implications?  This is an interesting and pertinent discussion and might provoke some warranted introspection.

Chapter 8 covers the various treatment options for athletes with various arrhythmia problems.  For athletes who don’t have trouble with arrhythmias, the discussion is educational in a broad sense.  For those who do have arrhthymias, though, there is ample detail here to become educated and be better engaged with your doctor(s) as you sort out the best treatment for you.

Finally, in Chapter 9, the authors wrap up with their “takeaway” on how we might prevent arrhythmia problems.

One of my favorite aspects of the book is the inclusion of Case Studies sprinkled throughout the text, where the authors illustrate their points in a side bar with the personal account of an athlete.  These stories bring us the human side of arrhythmias and show how difficult these problems can sometimes be.

This book is for….

  • the athlete with an arrhythmia problem.  There’s a lot of familiar territory here as well as the opportunity to learn more.  An educated patient is the ideal patient.
  • the athlete with simply an interest in the heart.  I can’t think of a better resource to become educated about the workings of the heart, particularly as they relate to the endurance athlete.
  • the athlete (or the athlete’s spouse or parent) who’s afraid of causing harm to the heart through exercise.  Be forewarned and be vigilant.

 

Related Posts:

  1. Heart to Start, by James Beckerman, MD
  2. The Exercise Cure, by Jordan Metzl, MD
  3. Cardiac Athletes, by Lars Andrews

Wellness Programming: Looking for Suggestions

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I need your help with a project at work.  Today, I’m looking for your suggestions about “wellness programming.”  I’m on a mission to learn.

The university medical center where I work recently acquired a local fitness center operation here in Jackson, Mississippi.  Its 4 branch facilities are being re-branded as University Wellness Centers.

Some of the readers here may know that academic medical centers are filled with committees–committees of the medical school, committees of the hospital, joint committees, ad hoc committees, etc.  The list seems endless.  For faculty members, there’s ordinarily a constant rotation of committee assignments.

Finally, I’ve gotten a new committee assignment that I’m looking forward to!  I’m one of a group of physicians who will serve on a physician advisory board for the new Wellness Centers.  We had our first meeting the other day and I’m excited about the possibilities.

One of our charges is to advise the Wellness Center management team about wellness programming.  I think this is a terrific opportunity to help improve the health of our community.  I’m looking for ideas that would:

  • Improve cardiovascular health in our community
  • Make use of the expertise and resources at our medical center
  • Provide fellowship and promote a sense of community
  • Be fun for the participants.

I’ll give you one example of what I’m talking about–the Heart to Start program at Providence Health & Services in Oregon.  Developed by James Beckerman, M.D., and now organized at two sites in the Portland area, the program enrolls participants in a 13-week training plan to walk or run in a 5k, 10k, or half marathon event.  This free program includes workout plans, heart-healthy resources, and a supportive online community.  Participants can participate in person or virtually on Facebook.  The photographs tell the story here–many smiling faces at the finish line.

This is just one program that has caught my attention.  Perhaps you’re aware of other programs in your own community.  Maybe you’ve participated.  I’d love to hear about your experiences.

Please leave a comment or send me an email with your suggestions.

Related Posts:

  1. Book Review: Heart to Start

Updated 2015 ACC/AHA Guidelines on Competitive Athletes with Cardiovascular Abnormalities

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The American College of Cardiology (ACC) and American Heart Association (AHA) have recently released a Scientific Statement on “Eligibility and Disqualification Recommendations for Competitive Athletes with Cardiovascular Abnormalities:  Preamble, Principles, and General Considerations.”  This 2015 edition is an update for the previous guidelines that were published as Proceedings from the 36th Bethesda Conference in 2005.

The new Guidelines were assembled by a large group of experts who were organized into 15 task forces.  Each of these task forces considered the current scientific evidence, graded the evidence, and reached consensus conclusions about recommendations that could be supported.  As such, this collection of recommendations represents the best available consensus expert opinion today in the United States.

It’s important to know that there is also a similar set of guidelines developed by the cardiology community in Europe.  There are differences between the ACC/AHA and European recommendations that often stem from legitimate differences of opinion.

It is also important to remember that the new ACC/AHA guidelines are targeted toward the young “competitive athlete.”  The authors define such an athlete as one “who participates in an organized team or individual sport that requires regular competition against others as a central component, places a high premium on excellence and achievement, and requires some form of systematic (and usually intense) training.”  As such, these guidelines are targeted primarily at student athletes of high school and college age (up through 25 years).  That said, the various recommendations may well be applicable to other athletes, including:  young but non-competitive athletes; older competitive athletes; and adult recreational athletes or exercisers.  Particular judgment must be used by physicians and athletes when extending the recommendations beyond the intended target population.

The new guidelines are some 115 pages long.  It’s not my intention to summarize things succinctly here in a blog post, but I thought it would be useful to point out what’s new….and what caught my attention in each of the 15 sections….

Task Force 1:  Classification of Sport–Dynamic, Static, and Impact

There is now a refinement of the former categorization of sports according to their “static” and “dynamic” components.  A new summary chart still uses the former I-II-III (static) and A-B-C (dynamic) scheme, but recognizes that there is actually a continuum along each axis.  In addition, a new table provides a useful categorization of sports according to their risk of impact, both at the junior high school and high school/college levels.  New recommendations for athletes taking various forms of anticoagulant medications caution against activities where impact injuries may be expected.

Task Force 2:  Preparticipation Screening

Preparticipation screening is widely applied in the United States for school-based athletic programs.  Controversy remains, though, about the effectiveness of history and physical examination alone for identifying serious cardiovascular abnormalities.  This Task Force continues to endorse the AHA 14-point screening guidelines or those of the American Academy of Pediatrics Preparticipation Physical Examination, suggesting particular value in standardization of questionnaire forms used.  The new guidelines suggest that the use of ECG in addition to history and physical examination may be appropriate in “relatively small cohorts” of young athletes, where physician expertise is available for counseling and follow-up of test results.  Mandatory screening with ECG is not recommended in young athletes or non-athletes.

Task Force 3:  Hypertrophic Cardiomyopathy (HCM), Arrhythmogenic Right Venricular Cardiomyopathy (ARVC), and Other Cardiomyopathies

The Task Force recognizes the heterogeneity of disease among athletes with hypertrophic cardiomyopathy (HCM) and advises that judgment is needed in the application of the recommendations in specific situations.  New from 2005, the guidelines now recognize that athletes with genotype-positive, phenotype-negative HCM (ie, carrying a gene but no overt manifestation[s] of the disease [yet]), and particularly if there is no family history of HCM-related sudden cardiac death, may participate in athletics.  The new guidelines advise against the use of pharmacologic agents or an implantable cardioverter-defibrillator (ICD) solely to facilitate participation in sports.  There are no major changes in the recommendations regarding ARVC, other cardiomyopathies, myocarditis, or pericarditis.

Task Force 4:  Congenital Heart Disease

There is a very long list of conditions that, together, constitute “congenital heart disease.”  These are inherited conditions that usually manifest during childhood, but sometimes these conditions may remain unrecognized until adulthood.  Exercise prescriptions are very specific to the particular condition, but the Task Force recognizes that many athletes with “corrected” congenital heart disease may participate fully.  Compared with 2005, the new recommendations remain similar or unchanged for:  atrial septal defect (ASD), ventricular septal defect (VSD), patent ductus arteriosus (PDA), pulmonary valve stenosis, aortic valve stenosis, coarctation of the aorta, elevated pulmonary vascular resistance (PVR), ventricular dysfunction after surgery for congenital heart disease, cyanotic heart disease including Tetralogy of Fallot, and Ebstein’s anomaly.  The new guidelines now provide greater detail in the recommendations for patients with transposition of the great arteries (TGA) treated by either atrial switch (eg, Mustard procedure, Senning procedure) or by more contemporary arterial switch operations.  In the area of coronary artery anomalies, additional evidence and experience now allows for recommendations for various subsets of patients, including those who have had surgical correction.

Task Force 5:  Valvular Heart Disease

The 4 most common valve problems are aortic stenosis (AS), aortic regurgitation (AR), mitral stenosis (MS), and mitral regurgitation (MR).  In many respects, the new guidelines parallel the former guidelines.  The new guidelines specifically recommend that athletes with these conditions, even if mild, should be evaluated yearly to determine whether sports participation can continue safely.  A new recommendation is offered for athletes with severe AR and normal left ventricular dimensions and function; it may be reasonable for these athletes to participate fully if they have normal exercise tolerance and echocardiography shows no progression of ventricular size or dysfunction.  MS is probably the least common of these valve conditions.  The new recommendations suggest that exercise testing to the anticipated level of sports activity may be useful in patients with MS to ensure that no symptoms develop.  The recommendations specifically recommend only low-intensity activities for those with severe MS, but most of these individuals would probably best be treated with valve repair or replacement.  Exercise testing is also recommended for asymptomatic patients with MR, again to the anticipated level of sports activity.

For those patients who have undergone operative procedures for valve repair or replacement, the guidelines make the important point that decisions about future participation in sports activities be made together, by both athlete and physician(s).

Task Force 6:  Hypertension

The new guidelines recommend that athletes with sustained hypertension undergo screening echocardiography.  For those with left ventricular hypertrophy (LVH) beyond what might be expected from “athlete’s heart,” activities should be curtailed until the hypertension is controlled.  The guidelines also remind athletes and treating physicians that some medications used for the treatment of hypertension (eg, beta-blockers, diuretics) are considered banned substances by some sports governing bodies.  Athletes should be aware that a therapeutic use exemption (TUE) may be required for participation, both outside and during competition.

Task Force 7:  Aortic Diseases, including Marfan Syndrome

There was a separate Task Force that reported on the collection of aortic diseases in the new guidelines.  In the previous version of the guidelines, these conditions were parceled out among the other task forces.  The new organization is helpful because all of the pertinent recommendations can easily be found in one place.  Particular mention is made of the importance that aortic size (eg, diameter) be considered in the context of the athlete’s size (eg, age, gender, body surface area).  In many circumstances, use of a z-score–the number of standard deviations above/below the mean for a size- or age-specific population–may be more appropriate than absolute measurements alone.

Athletes with Marfan syndrome or any of the other connective tissue disorders that affect the aorta (eg, Loeys-Dietz syndrome, Ehlers-Danlos syndrome, familial thoracic aortic aneurysm and dissection [TAAD] syndrome) should receive frequent reevaluation with echocardiogram, computed tomography (CT), and/or magnetic resonance imaging (MRI).  The recommendations regarding safe levels of activity parallel the previous guidelines.

For athletes with bicuspid aortic valve (BAV), the new guidelines focus on z-scores to define the degree of aortic enlargement:  not enlarged, z-score < 2; mild enlargement, z-score 2 to 2.5; moderate enlargement, z-score 2.5 to 3.5; severe enlargement, z-score >3.5.  Athletes with mild enlargement of the aorta should be confined to low-and moderate-intensity static and dynamic sports that do not have a likelihood of bodily injury.  In this group, intense weight training should be avoided.  Athletes with moderate enlargement of the aorta should participate in only low-intensity sports that do not have a likelihood of bodily injury.  And finally, those with a severely enlarged aorta should not participate in competitive sports.

Task Force 8:  Coronary Artery Disease

We think of coronary artery disease (CAD) as a disease of older individuals, but there are sometimes young athletes with acquired diseases of the coronary arteries.

One important aspect of the new guidelines in the area of coronary artery disease is the recommendation that athletes should participate in decisions about safe exercise with their physician(s), taking into consideration the health and psychological benefits of exercise as well as any potential risks.  The new guidelines are explicit that asymptomatic athletes with known CAD but with normal LV function and no inducible problems with stress testing should be able to participate fully in their sports.  For those who have had myocardial infarction (MI) or coronary revascularization procedure (eg, coronary artery bypass grafting [CABG] or coronary stenting), participation in sports activities should be curtailed for a period of 3 months.

A new section is devoted to the problem of spontaneous coronary artery dissection, a condition where a tear develops in the inner wall of the coronary artery itself, without warning and seemingly without explanation.  The new guidelines recognize that there is not yet sufficient experience and evidence with this problem to formulate specific recommendations, but that it may be reasonable to restrict affected athletes from high-intensity sports.

Also new in these guidelines is a section devoted to heart transplant recipients.  The guidelines recognize that for many such patients, participation in sports activities can be safe, especially if there is annual stress testing designed to demonstrate the safety of exercise up to the level of exertion that is anticipated during sports activities.

Task Force 9:  Arrhythmias

The section on athletes with arrhythmias is the longest and most complicated section of the new guidelines, in part because there are many different arrhythmias to consider.  This is an area where particular expertise on the part of the physician is required to make sound judgments about participation.

The recommendations suggest that athletes with permanent pacemakers can participate fully in sports if there is no limiting underlying heart condition or symptoms.  Those who are pacemaker-dependent (ie, require the pacemaker continuously to generate the heartbeat) should avoid sports in which a risk of collision might result in damage to the pacemaker system.  All others with a pacemaker should recognize the inherent risks of bodily injury that might also damage the pacemaker.

Atrial fibrillation (AF) deserves special mention because it is so common.  For athletes with AF, the new guidelines recommend evaluation that includes thyroid function tests, queries for drug use, an ECG, and an echocardiogram.  The new guidelines remind us that athletes with well-tolerated and low-risk AF may participate fully.  Those who are taking anticoagulants other than aspirin alone should consider the bleeding risk in deciding which sports activities may be safe.  Finally, the new guidelines recognize that catheter ablation for AF might eliminate the need for medications and should be considered in athlete patients.

The new guidelines suggest a similar evaluation for patient with atrial flutter.  For this condition, catheter ablation has a high likelihood of success and should be considered.

For athletes with SVT (eg, AV nodal reentry tachycardia, AV reciprocating tachycardia, atrial tachycardia), catheter ablation should be considered.

For athletes with ventricular arrhythmias (eg, premature ventricular contractions [PVC’s], non-sustained ventricular tachycardia [VT], sustained VT, or ventricular fibrillation), careful evaluation for underlying structural heart disease.  The algorithms for determining safe levels of exercise are complex and athletes should seek expert guidance.

The new guidelines have a new section on syncope, the problem of blacking out unexpectedly.  Athletes with exercise-induced syncope should be excluded from sports activities until a full evaluation is completed.  Cardiac causes of syncope can sometimes be life-threatening.  If the cause of syncope is determined to be neurally mediated, athletes can resume all sports activities once treatment measures are shown to be effective.  If no cause for the syncope can be determined, athletes should not participate in sports activities in which a transient loss of consciousness might result in serious bodily injury.

The final new section relates to athletes who have an implanted internal cardioverter-defibrillator (ICD).  The guidelines recommend that the indications for ICD implantation be no different for athletes and non-athletes.  In particular, an ICD should not be implanted solely to allow participation in sports.  For athletes with an ICD who have no episodes of ventricular arrhythmias that necessitate device defibrillation for a period of 3 months, participation in low-intensity sports activities may be reasonable.  Decisions about participation in sports activities with higher degrees of intensity, though, should consider the possibilities of greater likelihood of inappropriate shocks or device dislodgement with contact sports.

Task Force 10:  Cardiac Channelopathies

The new guidelines include the recommendations from a new Task Force devoted to the cardiac channelopathies.  These disorders are typically characterized by a structurally normal heart but a predisposition to develop syncope, seizures, or cardiac arrest from VT or VF.  At a cellular level, these disorders are caused by abnormalities in various ion channels in cardiac muscle cells that ordinarily permit the coordinated ebb and flow of charged ions with each heartbeat.  Approximately 1 per 1,000 individuals is affected by such conditions.  The most common types are long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), Brugada syndrome (BrS), early repolarization syndrome, short QT syndrome, and possibly idiopathic VF.

Historically, athletes with any channelopathy have been restricted from sports activities of all types because of the potential risk of sudden death.  Since the 2005 guidelines, though, much has been learned about the genetics, clinical manifestations, and course of these disorders.  It is now thought that some affected athletes may participate safely in sports activities.  The key, though, is careful evaluation by a cardiologist who specializes in heart rhythm disorders or by a genetic cardiologist.

Task Force 11:  Drugs and Performance Enhancing Substances

Not surprisingly, the guidelines contain the recommendation that athletes meet their nutritional needs through a healthy, balanced diet without dietary supplements.  The guidelines further recommend that the use of performance-enhancing drugs (PEDs) and supplements be prohibited by schools, universities, and other sponsoring organizations as a condition for participation.  The guidelines suggest the use of the principle of “unreasonable risk” (the potential for risk in the absence of defined benefit) as the standard for banning or recommending avoidance of substances being evaluated for use by athletes.

Importantly, the guidelines recommend that athletes receive formal education about the potential risks of PEDs and supplements, including the specific risks of sudden death and acute myocardial infarction.

Task Force 12:  Emergency Action Plans, CPR, AED’s

The new guidelines include the recommendation that schools and other organizations that host athletic events have an emergency action plan that includes provision of basic life support (BLS), the use of an automatic external defibrillator (AED), and activation of the emergency medical system (EMS).  Coaches and athletic trainers should be trained in CPR and the use of an AED and the AED should be available within 5 minutes, if needed.

Task Force 13:  Commotio Cordis

Commotio cordis is an unusual event, but t is important for coaches, athletes, and officials to be aware of this possibility and be prepared to respond to a lifeless victim.  Prompt initiation of bystander CPR and early defibrillation are the keys to survival.

Task Force 14:  Sickle Cell Trait

A section devoted to sickle cell trait (SCT) is included in the new guidelines.  Although athletes with SCT may participate fully in their sports, the guidelines recommend strategies such as adequate rest and hydration to reduce the likelihood of an event occurring during sports participation.  This risk is greatest during periods of high environmental temperature or extreme altitude.

Task Force 15:  Legal Aspects

The section of the new guidelines devoted to legal aspects considers the various conflicts that may arise when the guidelines are put into practice.

Related Posts:

  1. New ACC/AHA Heart Health Guidelines and Implications for Athletes
  2. Cardiac Screening for Adult Recreational Athletes
  3. Debate Continues on Cardiac Screening for Young Athletes

Interesting Research Studies from the ACC’15 Meeting

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This year’s annual meeting of the American College of Cardiology (ACC) was held recently in San Diego.  I thought I’d share a round-up of some of the sports cardiology studies that caught my eye.  In the months ahead, we can look forward to seeing the published reports.  Here are my Top 8:

1. Life expectancy of elite long and short distance runners.  In a study reported by Lee-Heidenreich D et al., the longevity of male Olympic athletes who competed in either the 100m dash or the marathon was examined.  The study included the top 20 finishers in each event at the Olympic Games from 1928 to 1960.  The investigators were able to determine the date of death for the majority (67%) of these athletes.  At the time of their Olympic races, the short distance runners were younger than the long distance runners (23.8 vs 30.5 years).  The life expectancy after their races were fairly similar (45.5 vs. 43.8 years), slightly favoring the short distance runners.  But because of their older age at the time of their Olympic event, the marathoners actually enjoyed greater longevity overall.

My take:  This is an interesting observation.  No doubt, though, many variables influence longevity and it’s probably simplistic to think that the long- vs. short-distance issue explains all (or even most) of the longevity difference.  I certainly wouldn’t encourage short distance runners to go long!

2.  An assessment of the performance of pre-participation guidelines applied to novice older endurance athletes.  This continues to be an important topic because there is no consensus about the best approach to screen adult recreational athletes for underlying cardiac conditions that might place them at risk.  In this report by Matsumura ME et al., the use of either the American Heart Association (AHA)/American College of Sports Medicine (ACSM) Pre-Participation Questionnaire (AAPQ) or the 2001 Working Group on Masters Athletes guidelines were considered.  The investigators surveyed 1457 novice runners and triathletes who were 35+ years old about the items included in the 2 screening tools.  If the AAPQ criteria were applied, 42% of the athletes would be told they should have additional cardiac testing.  If the Masters criteria were applied, 75% of the athletes would be told they should have additional cardiac testing.

My take:  These screening questionnaires identify a rather large group of masters athletes who would require additional testing.  It’s difficult to know how to find the balance here.  We want to find athletes who truly have an important (hidden) heart problem, but avoid unnecessary diagnostic testing in those who don’t.  It’s worth reading my previous blog post on another, recently published report on the topic of cardiac screening in adult recreational athletes.

3.  Results from the coronary anomalies program at Texas Children’s Hospital.  Anomalous coronary arteries (ACA, an inherited condition in which a coronary artery has an abnormal anatomy) are the 2nd leading cause of sudden cardiac death in young athletes.  The investigators report on the successes of a multidisciplinary team approach to patient care, imaging studies, treatment, and long-term follow-up of pediatric patients with ACA.  Among 58 patients, operation for surgical repair was recommend in 29 patients; 4 declined and 25 underwent operation.  There were significant surgical complications in 4 patients.  After operation, all 25 patients were able to return to exercise activities without restriction and none of these patients experienced any cardiac difficulties after operation.

My take:  A multidisciplinary team that includes pediatric cardiologists, radiologists, and cardiac surgeons is almost essential to care for patients with ACA.

4.  Screening with echocardiography or stress testing in asymptomatic USAF aviators–Not efficacious.  The issue of cardiac screening for seemingly healthy adult athletes continues to be debated.  In this study, the investigators report on an interesting experience with US Air Force (USAF) pilot applicants who, prior to 2008, underwent routine screening with echocardiogram and some form of exercise stress testing.  Between 1994 and 2006, 20,208 screening echocardiograms were performed; a “permanently disqualifying diagnosis” was found in only 9 individuals (0.045%).  The most common abnormalities detected were bicuspid aortic valve (in 0.76%), mitral valve prolapse (in 0.025%), and mild aortic regurgitation (in 0.29%).  In a subgroup of 903 aviators who underwent stress testing, only 16% of those with an abnormal results were later found to have significant coronary artery disease with coronary arteriography.  And moreover, regardless of the results of the stress testing, there was a very low rate (~0.5%) of later problems with death, heart attack, or need for revascularization (bypass surgery or coronary stent).  The authors concluded that screening echocardiography and stress testing was not useful in healthy individuals without cardiac risk factors and suggested that the results could be extended to the healthy athlete population as well.

My take:  The diagnostic yield for screening tests among healthy individuals will always be low.  That’s how screening tests work, by design.  We have to ask ourselves:  What’s it worth to identify the 9 individuals who were disqualified from flying?  Perspective matters here.  If you were a member of a potential flight crew or a potential passenger, you’d want to know that your pilot was healthy!

5.  Are years of training an independent predictor of atrial fibrillation in older runners?  There’s plenty of evidence to suggest a link between long-term endurance sport and atrial arrhythmias like atrial fibrillation (AF).  In this study, the investigators wanted to determine for runners if this relationship was independent from other known risk factors for AF such as age.  They reviewed data on 2819 runners that was collected as part of the MASTERS Athletic Study, a web-based survey of endurance athletes.  The data set included information about AF as well as the athletes’ run training and race participation.  The mean age of the athletes was 48.4 years and the median range of running career duration was 11-15 years.  The rate of reported AF was 2.4%.  There was a significant correlation between the accumulated years of running and the rate of AF, with a 6.1% rate of AF among those who had run for 30 years.  Independent risk factors for AF included:  increasing athlete age, high blood pressure, and years of accumulated running.  Variables that were not risk factors included:  diabetes, average running pace, use of speed training, and participation in marathons/ultramarathons.

My take:  There is ample evidence that long-term endurance sport is associated with AF.  There’s no good reason not to believe that the exercise is somehow causal, even if the mechanism remains uncertain.

6.  Incidence of sudden cardiac death associated with physical exertion in the Unites States military.  The Armed Forces Medical Examiner Tracking System includes information about all fatalities among military service members, including autopsy reports, death certificates, and official investigations.  From 2005-2010, there were 135 sudden cardiac deaths associated with exertion (SCDE) among 8,298,606 person-years of observation, giving an incidence rate of 1.63 per 100,000 person-years (p-y).  The incidence rate was higher for those >35 years (3.84 per 100,000 p-y), males (1.87 per 100,000 p-y), and African-Americans (3.00 per 100,000 p-y).

My take:  The US military is probably a relatively healthy cohort.  Nonetheless, we shouldn’t be surprised that there would be a small rate of SCDE.  Mention is not made in the abstract about what forms of exertion were involved, but we know that there is a finite rate of SCD associated with virtually any form of sporting activity, even if it doesn’t seem very strenuous.

7. Activities performed during sudden cardiac death associated with physical exertion in the United States military.  This is a companion study with #6, above, using the same source of data.  Here, the investigators studied the type of exercise that was associated with 200 cases of sudden cardiac death (SCD).  The most common types of exercise were:  running/elliptical (in 60%), generalized exercise such as furniture moving, construction, lawn mowing, dancing (in 10%), military P.T. (in 9%), walking (in 7%), swimming (in 4%), basketball (in 4%), and weight lifting (in 4%).  Interestingly, 20% of SCD events occurred during mandatory physical fitness tests; of these, 32% of events occurred during the test and 68% occurred within 1 hour afterwards.

My take:  Again, SCD can occur with any form of exercise.  The data here also point out that SCD may occur soon after exercise.  In the case of mandatory physical fitness testing, just as for athletic competition events, it’s important to organize medical support teams for the possibility of emergencies even after the event is completed.

8. QT interval in elite athletes.  We know that prolonged QT interval on the ECG, either inherited or acquired, is associated with increased risk for sudden cardiac death during exercise.  Here, the investigators wanted to learn if participation in sport, along with cardiac adaptations to exercise training, could itself cause prolongation of the QT interval.  The investigators reviewed the medical literature and identified 10 studies on 5354 elite athletes and 448 controls for whom QT interval data were available.  The QT interval in the elite athletes was, on average, 36 msec longer than for the non-athletic controls.  But once the data were corrected for the slower heart rates in the elite athletes, the corrected QT, or QTc, was not significantly different for the elite athletes and the non-athletic controls.

My take:  Participation is sport probably doesn’t cause prolongation of the QT interval and by itself lead to an increased risk of SCD.

 

Related Posts:

1.  Interesting Research Studies from the ACC’14 Meeting

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.

H2S

 

 

 

 

 

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