General Principles
The conveyance of exercise and lifestyle recommendations to young patients with genetic cardiovascular diseases (GCVD) requires substantial physician-patient interaction to ensure that recommendations are translated in sufficient detail. On the other hand, arbitrary and rigid directives would be impractical and most likely ineffective.
In communicating with patients, it is useful to define informal recreational sports by contrasting such activities with competitive sports. Because of the unique structure and pressures of organized sports, athletes with heart disease engaged in competition may not always use proper judgment in prudently extricating themselves immediately from vigorous exercise, even should they recognize the potential medical need to terminate the activity. For example, dizziness, palpitations, fatigue, excessive dyspnea, or chest discomfort (or any other potential warning sign of cardiovascular disease) experienced during competitive sports may be difficult for the participant to distinguish reliably from those innocent sensations that can normally accompany intense and extreme exercise and mimic symptoms of cardiac disease.
However, such considerations are not generally part of truly recreational sports activity, constituting a clear distinction on which exercise recommendations can be effectively conveyed to patients with GCVD. Participants in recreational physical activities have greater opportunity to exert reasonable control over their level of exercise and therefore are more likely to reliably detect cardiac symptoms and willfully terminate physical activity. On the other hand, some recreational sports (e.g., soccer, tennis, squash, and racquetball) can become truly competitive, largely owing to the style of play and attitudes of the participants, and thereby may obscure these important distinctions.
The panel has not included within the definition of recreational sports those neighborhood and elementary school activities for young children that involve lesser degrees of physical intensity and which should be an allowed component of daily activity for individuals with GCVD. Of note, some mildly symptomatic GCVD patients may be under the misconception that their functional limitation can be overcome by physical activity, rather than regarding symptoms provoked by exercise as "warning signs" triggered by their underlying heart disease.
Patient Recommendations
Sports activities have been categorized with regard to the high, moderate, and low levels of physical intensity required (see table below titled "Recommendations for the Acceptability of Recreational [Noncompetitive] Sports Activities and Exercise in patients with GCVDs"). These 3 partitions relate to the generally expected degree of physiological exertion implied by a sporting discipline. Patients with GCVD can safely participate in most forms of recreational exercise judged to be of moderate or low intensity (equivalent to 4 to 6 and <4 metabolic equivalents, respectively; Table).
Eligibility for exercise in specific recreational sports activities was assessed on a graded scale (from 0 to 5), with 0 to 1 designating activities generally not advised or strongly discouraged, 4 to 5 indicating activities probably permitted, and 2 to 3 indicating intermediate activities, which should be assessed on an individual basis. The assigned grades represent only an estimate, which assumes the usual level of physical exertion for a given recreational activity. However, in large measure, this grading system cannot take into account other potentially important variables such as the psychological burden and physical intensity uniquely brought to a sport by an individual participant or the potential effects 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. 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.
Furthermore, these recommendations are not intended for individuals with the following clinical features: history of important cardiac symptoms including syncope or other important episodes of impaired consciousness; prior cardiac operation (including surgical septal myectomy for obstructive hypertrophic cardiomyopathy [HCM] and aortic root reconstruction for Marfan syndrome) or heart transplantation; presence of an implanted cardioverter-defibrillator or pacemaker; and clinically overt and potentially life-threatening arrhythmias or other evidence of high-risk status. The presence of any of these features may require individual clinical judgment in adapting the present exercise recommendations.
Activities That Should Be Avoided
The panel also found it useful to express specific exercise recommendations in terms of those activities that should be avoided by patients with clinically diagnosed GCVD:
- "Burst" exertion (or sprinting), characterized by rapid acceleration and deceleration over short distances. Exercise of this type is encountered in a variety of sports, such as basketball (particularly full-court play), soccer, and tennis. Therefore, preference is given to recreational sporting activities such as informal jogging without a training regimen, biking on level terrain, or lap swimming, in which energy expenditure is largely stable and consistent, even over relatively long distances or periods of time.
- Extremely adverse environmental conditions, which may be associated with alterations in blood volume, electrolytes, and state of hydration and thereby increase risk, such as greatly elevated or particularly cold temperatures disproportionate to that which the athlete is accustomed to in temperate climates (i.e., >80 degrees F [27 degrees C] and <32 degrees F [0 degrees C]), high humidity, or substantial altitude.
- Exercise programs (even if recreational in nature) that require systematic and progressive levels of exertion and are focused on achieving higher levels of conditioning and excellence, as in road running, cycling, and rowing. Patients with GCVDs such as HCM, in which limiting dyspnea may occur with exercise, should be discouraged from any exertion that provokes these symptoms. These individuals are also advised against systematic training during which they are extended beyond the physical limits imposed by their underlying disease and the average aerobic state expected at that age.
- Excessive participation in sporting activities that otherwise would be regarded as recreational if performed in moderation (e.g., downhill skiing continuously over an entire day versus more limited and selective skiing over the same time period).
- Exercise-related and adrenergic-type activities or stress that conveys a risk for cardiac events, specific to certain disease states. For example, in long-QT syndrome (LQTS), swimming, abrupt loud noises (such as from a race starter’s pistol), and diving have been implicated as triggers for sudden death, particularly with certain mutant genes (i.e., KCNQ1 [or LQT1] for swimming and KCNH2/HERG [or LQT2] for auditory triggers). However, such laboratory-based molecular information is unlikely to be available to clinicians prospectively making exercise recommendations. Patients with rare conditions such as catecholaminergic polymorphic ventricular tachycardia (CPVT), in which many forms of exercise are associated with catecholamine release that triggers ventricular tachycardia, should be cautioned against virtually all forms of vigorous physical activity. The same restriction should be adopted for that subgroup of arrhythmogenic right ventricular cardiomyopathy (ARVC) patients that shares with CPVT both effort-induced polymorphic ventricular tachycardia and a mutant ryanodine receptor. It is also of note that a temperature-dependent dysfunction of the SCN5A gene for cardiac sodium channel has been characteristically observed in patients with Brugada syndrome (and Thr1620Met missense mutation). This increased temperature sensitivity could predispose some Brugada patients to life-threatening arrhythmias either during a febrile state or when body temperature increases during intense physical exertion.
- Intense static (isometric) exertion, such as lifting free weights, may prove to be adverse by inducing a Valsalva maneuver and dynamic left ventricular outflow obstruction in hypertrophic cardiomyopathy (HCM) (as well as the risk for traumatic injury in the event of impaired consciousness) or by increasing wall stress and weakening of the aortic media in Marfan syndrome, particularly if aortic dilatation is already present.
- Patients with diseases associated with impaired consciousness (e.g., syncope and near-syncope) are subject to considerably higher risk for traumatic injury while engaged in certain sports such as free weight and bench-pressing maneuvers, downhill skiing, diving, ice hockey, rock climbing, motorcycling, and horseback riding, and this factor should be taken into consideration in making recommendations to individual patients with GCVD.
- Although data are lacking, it is reasonable to specifically caution patients with GCVD, particularly those with catecholamine-sensitive or auditory-triggered arrhythmia syndromes such as long-QT syndrome (LQTS) and CPVT, against amusement park rides (e.g., roller coasters and thrill-related or frightening rides) because these are associated with intense stress and emotion due to sudden acceleration in heart rate and abrupt changes in centrifugal or centripetal forces.
- 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 (e.g., in recreational sports such as scuba diving and rock or mountain climbing). Water sports such as scuba diving or diving from platforms into pools are also generally unacceptable by virtue of their exposure of patients with GCVD (for whom syncope is a not-uncommon manifestation) to the risk of underwater drowning and reduced probability of rescue.
- Extreme sports (such as hang gliding and bungee jumping) are activities that are best avoided because they require the expenditure of particularly substantial physical energy and incur psychological demands that are exceedingly unpredictable, placing individuals with GCVD in compromised circumstances in which the likelihood of injury is substantial and the possibility of rescue from a traumatic or cardiovascular event is greatly reduced.
- Concomitant use of substances or compounds professed to promote enhanced physical performance but that also harbor the potential for adverse effects, particularly when associated with disease states or extreme environmental conditions (i.e., cocaine, anabolic steroids, or dietary and nutritional supplements such as ma huang, an herbal source of ephedrine [i.e., elemental ephedra] and a cardiac stimulant that is potentially arrhythmogenic).
Table: Recommendations for the Acceptability of Recreational (Noncompetitive) Sports Activities and Exercise in Patients with GCVDs*
| Intensity level |
HCM1 |
LQTS1 |
Marfan Syndrome2 |
ARVC |
Brugada Syndrome |
|
High
Basketball
Full court
Half court
Body building3
Ice hockey3
Racquetball/squash
Rock climbing3
Running (sprinting)
Skiing (downhill)3
Skiing (cross-country)
Soccer
Tennis (singles)
Touch (flag) football
Windsurfing4
|
0
0
1
0
0
1
0
2
2
0
0
1
1
|
0
0
1
0
2
1
0
2
3
0
0
1
0 |
2
2
0
1
2
1
2
2
2
2
3
3
1 |
1
1
1
0
0
1
0
1
1
0
0
1
1 |
2
2
1
0
2
1
2
1
4
2
2
3
1 |
|
Moderate
Baseball/softball
Biking
Modest hiking
Motorcycling3
Jogging
Sailing4
Surfing4
Swimming (lap)4
Tennis (doubles)
Treadmill/stationary bicycle
Weightlifting (free weights)3, 5
Hiking
|
2
4
4
3
3
3
2
5
4
5
1
3
|
2
4
5
1
3
3
0
0
4
5
1
3
|
2
3
5
2
3
2
1
3
4
4
0
3
|
2
2
2
2
2
2
1
3
3
3
1
2
|
4
5
4
2
5
4
1
4
4
5
1
4
|
|
Low
Bowling
Golf
Horseback riding3
Scuba diving4
Skating6
Snorkeling4
Weights (non-free weights)
Brisk walking
|
5
5
3
0
5
5
4
5
|
5
5
3
0
5
0
4
5 |
5
5
3
0
5
5
0
5
|
4
4
3
0
4
4
4
5
|
5
5
3
0
5
4
4
5 |
*Recreational sports are categorized with regard to high, moderate, and low levels of exercise and graded on a relative scale (from 0 to 5) for eligibility with 0 to 1 indicating generally not advised or strongly discouraged; 4 to 5 indicating probably permitted; and 2 to 3 indicating intermediate and to be assessed clinically on an individual basis. The designations of high, moderate, and low levels of exercise are equivalent to an estimated >6, 4 to 6, and <4 metabolic equivalents, respectively.
1Assumes absence of laboratory deoxyribonucleic acid (DNA) genotyping data; therefore, limited to clinical diagnosis.
2Assumes no or only mild aortic dilatation.
3These sports involve the potential for traumatic injury, which should be taken into consideration for individuals with a risk for impaired consciousness.
4The possibility of impaired consciousness occurring during water-related activities should be taken into account with respect to the clinical profile of the individual patient. Barotrauma is a primary risk associated with the use of the scuba apparatus in Marfan syndrome.
5Recommendations generally differ from those for weight-training machines (non-free weights), based largely on the potential risks of traumatic injury associated with episodes of impaired consciousness during bench-press maneuvers; otherwise, the physiological effects of all weight-training activities are regarded as similar with respect to the present recommendations.
6Individual sporting activity not associated with the team sport of ice hockey.
Special Circumstances
Physical Education Class
Issues related to recreational exercise often arise with regard to compulsory physical education classes in junior high or elementary school. In the former, the required levels of exercise in physical education classes vary considerably but often involve vigorous exertion and circumstances that are difficult to control. For example, although many components of such classes may be truly recreational, others clearly are not and can be regarded as competitive in nature (i.e., prolonged aerobic events such as the traditional timed 600-yard [or 400-meter] run and the President’s Physical Fitness Award). On the other hand, in elementary school physical education class, sports activities may involve nothing more than innocent play.
Although in the view of some very conservative clinicians, it might seem most prudent for patients with GCVDs to largely avoid any involvement in school-structured physical education, the guideline developers recognize that profound personal and psychological stigmata can be associated with such selective, targeted, and often unnecessary gym class prohibition. Indeed, in some states, such children are placed in alternative health classes, which results in further ostracism by their peers. In the event that the patient and family judge it important, for social and peer-related reasons, to retain some level of participation and normalcy among peers (as is often the case), careful and detailed review of physical education class requirements should be undertaken by the parents in concert with school officials and their physician, during which the principles of safe recreational activities are agreed upon.
This process will define acceptable portions of the curriculum and exclude activities that can be regarded as intense or competitive (particularly those involving burst exertion), although it may be challenging to distinguish recreational from competitive activity under these circumstances. In this regard, it should be determined whether physical education instructors will agree to (or are capable of) monitoring the patient’s activity level in accord with the medical recommendations. Therefore, the degree to which a child or adolescent with GCVD can or should participate in physical education class requires a large measure of individualization.
Implantable Cardioverter-Defibrillator
A growing number of young patients with GCVDs are receiving implantable defibrillators for primary or secondary prevention of sudden death. Such patients may participate in a wide variety of noncompetitive and noncontact physical activities in concert with the exercise recommendations of the responsible electrophysiologist. However, the defibrillator itself may create some restrictions to these activities, particularly with regard to the possibility that bodily trauma may disrupt the lead system or that certain levels of physical exertion may trigger an inappropriate shock due to sinus tachycardia. Therefore, young patients with GCVD undergoing implantation of a cardioverter-defibrillator should receive a dual-chamber device with algorithms that improve discrimination between ventricular and supraventricular arrhythmias, thereby reducing the incidence of inappropriate interventions. Participation in intense exercise should not be advocated explicitly because of the presence of an implanted defibrillator and the antiarrhythmic protection afforded by the device.
