I know this may seem a bit unusual to post on a dressage web-site,
but after having competed in dressage shows this weekend in high
temperatures (as many of us do), I thought I should pass it on as
something young riders and their parents might want to discuss with
their primary care physician regarding recreational sports
participation. The information is a review of published medical
literature available on Medscape (www.medscape.com).

Sarah Patrick (dressage enthusiast and . . .)
Professor/Director, Center for Rural Health Improvement
USD School of Medicine
Department of Family Medicine

New Guidelines for Sports Participation in Genetic Cardiovascular
Disease

News Author: Laurie Barclay, MD
CME Author: Charles Vega, MD, FAAFP
Authors and Disclosures

To earn CME credit, read the news brief, the paragraphs that follow,
and answer the questions below.


June 10, 2004 — The American Heart Association (AHA) has for the
first time issued a statement regarding generally acceptable and
relatively contraindicated sports activities for young patients with
genetic cardiovascular disease (GCVD). The new guidelines are
published in the June 8 issue of Circulation.

"A group of relatively uncommon but important genetic cardiovascular
diseases (GCVDs) are associated with increased risk for sudden
cardiac death during exercise, including hypertrophic cardiomyopathy,
long-QT syndrome, Marfan syndrome, and arrhythmogenic right
ventricular cardiomyopathy," write Barry J. Maron, MD, and colleagues
from the Working Groups of the AHA Committee on Exercise, Cardiac
Rehabilitation, and Prevention; Councils on Clinical Cardiology and
Cardiovascular Disease in the Young. "These conditions, characterized
by diverse phenotypic expression and genetic substrates, account for
a substantial proportion of unexpected and usually arrhythmia-based
fatal events during adolescence and young adulthood."

Although criteria exist for eligibility and disqualification for
competitive athletes with these GCVDs, the new AHA guidelines
represent the first systematic recommendations for the much larger
population of patients with GCVD who are not trained athletes, but
who wish to participate in recreational physical activities and
sports.

The guidelines note that athletes with heart disease engaged in
competitive sports may not always use proper judgment in terminating
vigorous exercise when they develop potential warning symptoms,
including dizziness, palpitations, fatigue, excessive dyspnea, or
chest discomfort.

The authors categorized sports activities as requiring high,
moderate, and low levels of physical intensity. Patients with GCVD
can safely participate in most forms of recreational exercise judged
to be of moderate (four to six metabolic equivalents) or low
intensity less than four metabolic equivalents).

Eligibility for exercise in specific recreational sports was graded
from 0 to 5, with 0 to 1 indicating activities generally not advised
or strongly discouraged, 4 to 5 indicating activities probably
permitted, and 2 to 3 indicating activities which should be assessed
individually. Other than the grading system, factors meriting
consideration include individual psychological and physical stress
associated with sports participation, use of cardioactive drugs,
environmental conditions, and the precise clinical profile.

"Therefore, these recommendations are, to a certain extent,
necessarily subjective and represent only a starting point for
clinical judgments in individual asymptomatic (or only very mildly
symptomatic) patients with clinically evident GCVD," the authors
write. "Consequently, their application requires substantial reliance
on the practice of the 'art of medicine' and the weighing of
perceived risk with respect to benefit for each patient."

These recommendations do not apply to individuals with a history of
important cardiac symptoms, including syncope, prior cardiac surgery,
presence of an implanted cardioverter-defibrillator or pacemaker, and
clinically overt and potentially life-threatening arrhythmias or
other evidence of high-risk status.

Patients with clinically diagnosed GCVD should avoid "burst" exertion
or sprinting, extremely adverse environmental conditions, exercise
programs requiring systematic and progressive levels of exertion
focused on achieving higher levels of conditioning and excellence,
any exertion that provokes limiting dyspnea, systematic training
beyond the physical limits imposed by their underlying disease and
age, excessive participation in otherwise recreational sporting
activities, and exercise-related and adrenergic-type activities or
stress conveying cardiac risk specific to certain disease states.

Other relatively contraindicated activities include intense static or
isometric exertion, hazardous activities posing increased risk for
traumatic injury in the event of impaired consciousness, amusement
park rides associated with intense stress and emotion, paired
athletic activities in which a second party may be at risk should the
individual with GCVD suddenly incur bodily injury or impairment of
consciousness and incapacitation, water sports such as scuba diving
or diving from platforms into pools, and extreme sports such as hang
gliding and bungee jumping.

Individuals with GCVD should also be warned against physical
performance "enhancers" such as cocaine, anabolic steroids, or ma
huang.

"The medical recommendations set forth in this document should not
and cannot be viewed as inflexible doctrine but rather should allow
sufficient latitude to the managing physician without precluding
individual clinical judgment," the authors write. "Compliance with
these recommendations is evidence that a physician has satisfied
[suggested] legal requirements and may form the basis of a successful
defense to allegations of malpractice."

Circulation. 2004;109:2807-2816

Learning Objectives
Upon completion of this activity, participants will be able to:
List different forms of GCVD.
Review recommendations for recreational physical activity in patients
with GCVD.

Clinical Context
GCVD is a rare but important cause of death for young people, and
mortality is usually associated with physical activity. In an
analysis of 158 sudden deaths of trained athletes that was published
in the July 17, 1996, issue of JAMA, Maron and colleagues found that
134 athletes had a cardiovascular cause of mortality, and the median
age of the athletes who died was 17 years. Players from basketball
and football teams accounted for 68% of deaths. The most common
conditions found at autopsy were hypertrophic cardiomegaly (HCM) and
anomalous coronary artery malformations.

The Maron study focused on trained athletes, whereas there are
currently no guidelines regarding physical activity for the more
common recreational athlete with GCVD. The current guidelines are
designed to fill this void.

Study Highlights
The consensus statement was drafted by cardiovascular specialists and
molecular biologists with special expertise on the relationship
between exercise and cardiovascular disease. They based their
opinions on the best current evidence available but focused on
patients younger than 40 years old with GCVD but without limiting
cardiac symptoms, a history of prior cardiac operation or implanted
defibrillator or pacemaker, or clinically overt arrhythmias.
The authors caution at several points in the article that these
recommendations are only guidelines and are not meant to replace
clinical judgment. They also assumed that the reduced intensity of
recreational exercise puts casual athletes with GCVD at lower
cardiovascular risk than competitive athletes with the same class of
cardiac disorders.

GCVD was defined as HCM, arrhythmogenic right ventricular
cardiomyopathy (ARVC), Marfan syndrome, long-QT syndrome (LQTS),
Brugada syndrome, and catecholaminergic polymorphic ventricular
tachycardia (CPVT). Recreational athletes were defined as those who
participated at a modest to vigorous level in sports on either a
regular or inconsistent basis.

Genetic analysis did not play a prominent role in the authors'
recommendations, as they expect most physicians to concentrate on
patients' phenotype.

General recommendations included self-monitoring for patients with
GCVD during exercise and cessation of activity if cardiovascular
symptoms such as dizziness or palpitations should develop.
The authors recommend that patients with GCVD may participate in
activity that requires less than 6 metabolic equivalents of energy
expenditure. High intensity sports such as basketball, body-building,
soccer, and sprinting are generally not recommended. However,
moderate-intensity activities such as biking, jogging, and lap
swimming appear to be safe (although caution is still advised in
patients with ARVC). Low-intensity activity such as golf, bowling,
and brisk walking can also be pursued by all asymptomatic patients
with GCVD.

The authors recommend against patients with GCVD participating in
sports which require a burst of energy (eg, sprinting or basketball),
participating in physical activity in extreme heat or cold, excessive
participation in sports that would be safe in moderation, or
participation in "extreme" sports.

The consensus panel also recommends against patients with GCVD
progressively increasing exertion in a training regimen for a
particular sport. Intense isometric exertion which could produce a
Valsalva maneuver, as in weight lifting, is also discouraged.
The authors state that enrolling children with GCVD in physical
education classes needs to balance physical safety with social
integration and the maintenance of a certain level of activity for
health of the child. They recommend the collaboration of parents,
school officials, physical education teachers, and physicians in the
review and implementation of an activity plan that accounts for these
issues.

Patients with GCVD undergoing implantable cardioverter-defibrillator
placement should receive a dual-chamber device programmed to improve
discrimination between ventricular and supraventricular arrhythmias.
This should reduce the risk of inappropriate electric shock in the
case of tachycardia with exercise.

Pearls for Practice
Athletes with GCVD are at increased risk of mortality with intense
exercise. Mild- and moderate-intensity forms of exercise appear safe
for most asymptomatic patients with GCVD.