Assessing heart health more accurately

Intense physical training can cause structural and functional changes to the heart’s muscles. Described as “athlete’s heart,” the changes pose no medical danger but are frequently misdiagnosed. That’s in part because existing screening methods don’t differentiate well between athlete’s heart and a heart disease called left ventricular noncompaction cardiomyopathy (LVNC), in which the lower left chamber of the heart develops abnormally. Misdiagnosis of athlete’s heart as LVNC, a disease that carries the risk of sudden cardiac death, can pause or even terminate a young person’s athletic pursuits.

In a study published Oct. 8 in the International Journal of Cardiology, researchers at the universities of Exeter and Bristol reported on a newly developed screening method that can distinguish between the two conditions. The new method, which is inexpensive and easy to implement, has the potential to prevent a healthy person’s athletic ambitions from being crushed unnecessarily.

The study included 417 male soccer players ages 11-18. The participants were enrolled between 2014 and 2019 at one of three sports academies: Manchester United Football Club in Britain, Doha Aspire Academy in Qatar, and Barcelona Football Club in Spain.

Using a noninvasive imaging technique called speckle tracking echocardiography, the researchers were able to eliminate all false positive LVNC diagnoses in the soccer players. Lead study author Craig Williams, professor of Pediatric Physiology and Health and director of the Children’s Health and Exercise Research Centre at the University of Exeter, described speckle tracking echocardiography in an email to WORLD as a simple ultrasound test. When ultrasound waves pass through the human body, he explained, they are reflected or absorbed differently based on tissue density, producing tiny dots of varying brightness. These dots, called speckles, can be traced with image processing software to capture information about the heart muscle.

At the beginning of each season, the soccer players were evaluated using widely accepted criteria to determine their eligibility for an LVNC diagnosis. Based on these four criteria, 6.5 percent of the athletes were considered LVNC-positive. However, after conducting speckle tracking echocardiography the researchers found no irregularities in the muscular tissue of the soccer players’ hearts, implying that the accepted criteria for a positive LVNC diagnosis significantly overestimates its prevalence.

Mark Link, a clinical cardiologist specializing in electrophysiology, noted that speckle tracking echocardiography is more accurate and much less expensive than the alternative frequently used in clinical practice, cardiac magnetic resonance imaging.

Williams explained that most modern ultrasound machines have a speckle tracking echocardiography feature. However, he cautioned that while there is no major expense in performing the test, it can be costly to hire a sports cardiologist able to interpret the results.

Link commended the paper’s authors for a well-designed study with significant implications. “The importance of this retrospective study is that left ventricular noncompaction is often overdiagnosed in athletes, and it’s a problem because then they shouldn’t be playing sports,” he said.

But Link also suggested the idea that people with cardiomyopathy shouldn’t pursue athletics isn’t entirely accurate. He explained that the negative association between cardiomyopathy and extreme exercise is based on old registries of athletes who died. Many of these athletes had cardiomyopathies. “To some extent [cardiomyopathies are] putting you at increased risk, but probably not nearly as high as we used to think in the past,” he said. Link said more and more data is coming out showing that exercise can be beneficial to people with certain types of cardiomyopathies.

Williams thinks there are instances in which a person with LVNC should refrain from intense exercise. He said that if an LVNC-positive patient meets several clinical criteria, such as a family history of cardiac issues, an irregular heartbeat, and heart pump failure, he or she should not participate in strenuous exercise.

Williams’ group is set to publish a second study showing that speckle tracking echocardiography can also be used to distinguish another oft-misdiagnosed heart disease, arrhythmogenic cardiomyopathy, from athlete’s heart. “Giving an accurate diagnosis means at the same time not missing a disease when it is there, but equally important, not finding one where none exists,” he said. “We hope our research contributes to both these goals in a meaningful manner.”