A recent study by Marc P Waase (Columbia University Medical Center, New York, USA) et al published in the Journal of the American Medical Association (JAMA) found that abnormal electrocardiograms (ECGs) are common among professional basketball players in the USA.
The US National Basketball Association (NBA) collaborated with Columbia University Medical Center to produce the observational study based on annual ECGs and stress echocardiograms, seeking to identify test markers of abnormal heart function that put athletes at risk. JAMA acknowledges that although cardiac death among professional athletes is rare, high-profile cases cause “intense interest” in this demographic.
Data from 519 male NBA athletes were analysed using three different athlete specific interpretation criteria: Seattle, refined and international. Quantitative ECG measures included heart rate, QRS duration, corrected QT interval, and PR interval. Two-dimensional transthoracic echocardiograms were also performed, as well as left ventricular (LV) mass and relative wall thickness measurements. The amount of abnormal ECGs differed for different interpretations, with 131 (25.2%) abnormal findings under Seattle criteria, 108 (20.8%) under refined and 81 (15.6%) under international criteria. Precordial QRS voltages were found to be greater in African American athletes than in white athletes, with no significant differences in limb lead voltages. A majority 89% (462) of athletes had a minimum of one ECG change related to training, with two or more training-related ECG changes observed in 63% (327) of the athletes.
Development of LV concentric remodelling was observed to have a significant influence on repolarisation and ECG abnormalities, and abnormal T-wave inversions was the most common abnormality. Among the 163 athletes in the highest tertile of LV relative wall thickness, 41 (25.2%) had abnormal ECGs, compared with 16 (9.3%) of the 172 athletes in the lowest tertile. Older athletes (27–39 years) more often showed ECG abnormalities, with 36 affected athletes (n=159; 22.6%) in this age range, compared to only 17 affected (n=186; 9.1%) in the youngest athlete group (18–22).
In conclusion, Waase et al write that the athlete-specific international criteria “improved ECG specificity over previous ECG interpretation criteria in NBA players”, but added that abnormal ECG classification nevertheless remained high.