Exercise-Induced ECG Abnormalities And The Need For Athletic Health Checks

Exercise-Induced ECG Abnormalities And The Need For Athletic Health Checks


Exercise-induced ECG abnormalities in athletes have become a growing problem in sports medicine. Although some of these athletes may have ECG abnormalities, the routine use of ECGs for screening athletes is debated. The issue revolves around actual abnormal findings and pseudo-abnormal findings. There is no doubt that all athletes should undergo a pre-participation evaluation, but a routine ECG is usually not required.

This blog highlights important aspects of the ECG if it is felt that an ECG is warranted. Stay tuned to learn how to catch potential problems early and keep our athletes healthy and strong!

Exercise-Induced ECG Abnormalities In Athletes

While exercise-induced ECG abnormalities are common in athletes, it’s important to understand what these changes mean and when they might signal a more serious issue. Regular sports health screenings focusing on signs, symptoms, and family history are paramount.

Cardiac Adaptation To Exercise

Intense physical training causes a series of changes in the heart called cardiac adaptations. These structural and functional changes, such as sinus bradycardia or sinus arrhythmia, often show up on an athlete’s electrocardiogram.

Regular, intense exercise can lead to improved diastolic function—an important aspect of cardiac performance during exercise. Exercise-related ECG abnormalities are indicators of these adaptations at work.

It’s worth noting that some ECG changes may serve as evidence of exercise-induced cardiac remodeling. For example, “athlete’s heart,” a condition characterized by changes in the left ventricle due to frequent exercise, is usually harmless but conspicuous on an ECG scan.

Understanding the nature of these changes helps physicians distinguish between normal responses to exercise and possible signs of underlying pathology.

Pathological ECG Findings

Pathologic ECG abnormalities can occur because of the electrical and structural changes in the heart caused by consistent exercise training. Wide QRS, an abnormal axis, and an inadequate response to sinus frequency during exercise are all useful markers of potential conduction abnormalities.

However, distinguishing between truly pathologic conditions and normal adaptations characteristic of an athlete’s heart is important to avoid unnecessary interventions such as diagnostic testing or limitation of exercise.

Certain ECG abnormalities typically correlate with the intensity of exercise and the degree of cardiovascular adaptation achieved through routine training. Understanding these nuances helps physicians navigate this complex scenario effectively and provide optimal care for their athlete patients.

Abnormal T-wave Inversion

Abnormal T-wave inversion on ECG is often associated with mild underlying cardiac arrhythmias or a family history of cardiomyopathy and ion channelopathies. In some cases, deep T-wave inversions can occur even in asymptomatic athletes. The significance of these findings becomes even greater when one considers that approximately 6% of athletes who present with such ECG abnormalities develop cardiomyopathy over the course of 12 years.

Of particular concern is the presence of this inversion in the inferior leads, which necessitates further investigation to ensure the safety of athletes and reduce the potential risks for sudden cardiac events.

ST-segment Depression

ST-segment depression is a common finding during exercise. Distinguishing between normal ST-segment depression and pathological ST-segment depression can be challenging. There are criteria to distinguish this and false-positive results are common in athletes.

It’s important to note that athletes with this abnormality may require further investigation, including cardiac imaging, exercise testing, and prolonged rhythm monitoring. Interestingly, studies have shown that ischemic-like changes in the exercise ECG are reproducible across multiple tests in athletes. This underscores the importance of detecting and assessing ST-segment depression to ensure appropriate care and treatment of these individuals.

Ventricular Arrhythmias

Ventricular arrhythmias are abnormal heart rhythms in the pumping chambers of the heart. These arrhythmias can be dangerous as they are associated with an increased risk of sudden cardiac death in athletes.

Understanding exercise-induced ECG abnormalities is important to detect and treat ventricular arrhythmias early. Some athletes may have normal cardiac function at rest but may still suffer from right ventricular dysfunction and arrhythmias during exercise.

Young competitive athletes with cardiovascular abnormalities have a higher risk of developing ventricular arrhythmias during exercise. Some famous athletes have had serious or even fatal ventricular arrhythmias due to underlying heart diseases such as hypertrophic cardiomyopathy, Brugada syndrome, congenital prolonged QT syndrome, or arrhythmogenic right ventricular dysplasia.

The Importance Of Athletic Screening

Athletic screenings not only protect the health and safety of athletes but also contribute to enhancing athletic performance. They’re an investment in the athlete’s health, assisting in the early detection of potential issues, prevention of health issues on the field, promoting faster recovery, and ultimately supporting a long and successful athletic career.

Early Detection Of Cardiac Abnormalities

Regular pre-participation screening allows healthcare professionals to identify potential heart disease before it becomes life-threatening. Screenings can uncover silent cardiovascular abnormalities that may not have apparent symptoms, allowing for timely intervention and treatment.

Effective diagnostic methods, such as 12-lead ECG, can detect conditions associated with sudden cardiac death, although rare, and treat them appropriately. Realize though, that routine ECGs are not recommended by the American Heart Association/American College of Cardiology for all athletes.

Ensuring Athlete Safety

Regular, intense exercise can lead to structural and electrophysiological adaptations of the heart. Most of the time these changes are physiologic and not pathologic. However, it’s important to know that athletes with ECG abnormalities don’t necessarily have heart disease.

Pre-participation screening athletes for heart disease helps ensure their safety during physical activity. By detecting individual abnormalities through screening before participation in sports, medical personnel can prevent sports-related injuries and even death.

Optimizing Athletic Performance

Regular screenings can also help to prevent overtraining—a common issue among athletes striving to reach their peak performance. Overtraining can lead to various health issues, including increased risk of injury, decreased immune function, and hormonal imbalances.

By monitoring an athlete’s health, athletic screenings can help to identify signs of overtraining early, such as an unusually high heart rate or prolonged recovery times. With this information, training schedules can be adjusted to allow for adequate rest and recovery, preventing the negative effects of overtraining and promoting optimal performance.

These screenings provide a comprehensive picture of an athlete’s health and fitness. When conducted regularly, they track the athlete’s progress over time, capturing valuable data about their physical condition.

Electrocardiographic Evaluation And Guidelines For Athletes

By following these guidelines, athletes, coaches, and healthcare providers can ensure that potential cardiac issues are detected early and managed appropriately, reinforcing the safety of athletes during their athletic pursuits.

Interpreting The Athlete’s ECG

Interpreting an athlete’s ECG is critical in determining cardiac health and identifying potential abnormalities. Here are the most important factors to consider:

  1. T-wave Inversion: Although T-wave inversion is a common finding in athletes, it may also indicate a pathologic condition, especially if it is widespread or accompanied by other abnormalities.
  2. ST-Segment depression: Exercise-induced ST-segment depression should be carefully investigated, as it may indicate myocardial ischemia or other underlying cardiac problems.
  3. Ventricular Arrhythmias: Any ventricular arrhythmias observed during exercise should be thoroughly investigated as they may be a risk for sudden cardiac events.
  4. False Positives: Distinguishing between exercise-related and pathologic ECG changes can be difficult and lead to false-positive results. This underscores the need for a comprehensive evaluation beyond the ECG.
  5. Comprehensive Evaluation: Athletes with abnormal ECGs undergo a comprehensive evaluation that includes additional cardiac imaging, exercise testing, prolonged rhythm monitoring, and family history to assess their cardiac health further as indicated.


Guidelines For ECG Screening In Athletes

When deciding to include ECG screening in health examinations of athletes, several factors should be considered, including:

  • Frequency of Screening: Professional athletes are recommended to have an ECG as part of their screening before participation and at regular intervals after that, usually every two years. Amateur athletes or athletes participating in moderate to high-impact sports should have pre-participation exams and in some cases, an ECG is considered.
  • Interpretation of Results: ECG results in athletes can be complex due to the physiological changes in the heart. ECGs should be interpreted by healthcare professionals with expertise in sports cardiology to differentiate between normal athletic adaptations and possible cardiac disease.
  • Follow-up: If the ECG reveals potential problems, further testing is considered, such as echocardiography or exercise testing. Which follow-up tests are performed depends on the nature of the ECG findings and should be determined by a professional.


Sign Up For An ECG Interpretation Course Today

If you’re looking to refresh your current skills or improve your understanding of ECG interpretation, ECGEDU’s courses are designed to provide a deeper knowledge of ECG interpretation. They’re ideal for professionals at all levels – whether you’re an experienced physician or a medical student.

Don’t miss this opportunity to boost your ECG interpretation skills, earn CME/CEU/CEC credits, and provide better patient care. Click here to register for one of ECGEDU’s courses today and take the next step in your career path.



Prashant Rao, MBBS; David M. Shipon, MD, FACC,  Implementing a Cardiac Screening Program: Should We Be Using an ECG? JACC, 9/26/2019.

Dr. Scott Siegal

Dr. Scott Siegal

Dr. Scott Siegal is the founder and lead instructor on ECGEDU.com. He is a board-certified cardiologist whose mission is to promote education and foster conversations about critical thinking. Learn more about ECGs, echocardiography, cardiology, and Dr. Siegal at ECGedu.com.