Can chronic exercise cause thickening of the heart wall?

Question

Hi doctor,

My son is 12 years old, very active, plays representative basketball, and attends a sports high school. Last Sunday, he was knocked over while playing and hurt his arm. After getting up, he fainted but was fine afterward. There were no broken bones, but the medical center performed an ECG, which indicated a non-confirmed diagnosis of incomplete right bundle branch block (RBBB) with marked left ventricular hypertrophy.

We consulted a pediatrician, who said that his ECG could be normal but recommended that seeing a cardiologist might provide us with reassurance. I have scheduled an appointment with a cardiologist, but I would like some reassurance since the appointment is a month away. The pediatrician's report mentions an incidental finding of partial RBBB and slightly tall R waves in leads V4-V6. I have a copy of the ECG if needed.

Please advise.

Answer 1

Hi,

Welcome to icliniq.com.

The ECG (electrocardiogram) (attachments removed to protect the patient’s identity) shows incomplete right bundle branch block (RBBB) or early RBBB, along with features of left ventricular hypertrophy. Additionally, the heart rate is on the lower side, nearing 60 beats per minute. However, as you mentioned, he is a basketball player. Athletic individuals or those who engage in regular exercise can exhibit these changes, a condition referred to as "athletic heart". Therefore, the first possibility is an athletic heart.

Due to chronic exercise, there is a thickening of the heart wall, similar to how our biceps develop with workouts. This thickening is seen as hypertrophy on the ECG and may lead to RBBB and minor conduction abnormalities. Overall, this does not appear to be worrisome, but we need to rule out hypertrophic cardiomyopathy, especially since he has experienced fainting. An echocardiogram will be necessary to confirm the findings. Fainting may also occur due to pain or inadequate food intake. I assume there is no family history of sudden unexplained cardiac deaths. Therefore, please arrange for his echocardiogram and try to limit his sporting activities until the procedure. Ensure he drinks plenty of water and oral fluids to avoid fainting and syncope.

I hope this helps.

Thank you.