Sudden cardiac death in athletes and dancers

by lola evans

Athletes are often regarded as role models of peak fitness, capable of the most impressive physical feats yet they face some of the highest rates of sudden cardiac death (SCD). Incidents involving high profile footballers have piqued public interest and encouraged academic inquiry. Although not a new phenomenon, the amount of research in the sporting population has expanded in recent years; nonetheless, as a dancer myself, I was left wondering to what extent dancers are at risk and what protections are in place. 

SCD is often defined as an unexpected death occurring within one hour of the onset of symptoms. Estimates of the incidence vary widely from 1 in 3,000 athletes per year in some sub populations to 1 in 200,000. 

Many existing studies rely on retrospectively collecting data from media reports to identify SCDs which underestimate the rates in the general population. To make matters more complicated, certain cardiac conditions where there are problems with the heart’s rhythm can be difficult to diagnose after death, contributing further to underestimates. 

The cause of SCD is most commonly attributed to an undiagnosed heart condition, which invites the question: can these conditions be detected, and premature deaths prevented?

During exercise, the heart is under additional strain, working harder to supply muscles and other parts of the body with oxygenated blood. Any undiagnosed heart conditions that affect the heart's physical structure or its rhythm can have unpredictable effects during exercise such as sudden loss of function or cardiac arrest. Abnormal heart structure is one of the most cited causes of SCD in young active people. 

The most common abnormality is hypertrophic cardiomyopathy (HCM) where the muscle cells within the heart are larger than normal causing the chambers of the heart to be stiffer and smaller. This reduces the volume of blood the heart can hold and can lead to leaky valves and a backflow of blood. 

One further complication is that under repeated episodes of intense physical exercise the heart can adapt to develop advantageous physical characteristics sometimes referred to as ‘athlete’s heart’. This might include thicker muscle around the left ventricle, the part of the heart that is responsible for pumping oxygen-rich blood around the entire body. These advantages can cause problems during athletic screening as they can mimic the appearance of heart conditions that may cause SCD, possibly leading to missed or false diagnoses.

So, is there such a thing as a ‘dancer’s heart’? There is very little published data regarding the dancer’s heart and whether dance puts the heart under enough physical strain to alter its structure or expose dancers to the risk of SCD. One study discovered that within a cohort of ballet dancers 48% revealed a mitral valve prolapse which while usually benign can cause complications leading to SCD. This is a high proportion of the sample, and it may be attributable to low weight relative to height instead of the exercise induced effects of ballet. 

The topic of screening athletes has been a highly debated topic within the sporting community, some believe nationwide screening will save lives whilst others believe screening can cause harm to young active people. Screening hopes to detect heart conditions early in order to manage conditions appropriately and reduce the risk of SCD. 

Existing research looking at the possibility of a nationwide screening programme is conflicting. Some studies say screening can easily save lives and is cost effective, whereas others disagree highlighting the impact of false positives causing unnecessary anxiety and premature withdrawal from sport.

There is undoubtedly a bigger problem out there than we currently know about. More lives could be saved, but the lack of reliable data on the incidence and practical approaches is holding us back from being able to construct effective screening to protect active people.

Article Details
Sudden Cardiac Death in Dancers and Athletes: Time for Increased Cardiac Screening?
Lola Evans, Kim Hutt
First Published October 20, 2023 Article Commentary
DOI: 10.1177/1089313X231203052
Journal of Dance Medicine & Science

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