https://doi.org/10.1007/s00392-025-02625-4
1Universitätsklinikum des Saarlandes Innere Medizin III - Kardiologie, Angiologie und internistische Intensivmedizin Homburg/Saar, Deutschland; 2Internal medicine and sports medicine Quierschied, Deutschland
Background
In athletes distinguishing physiological from pathological cardiac remodelling such as hypertrophic cardiomyopathy (HCM) can be difficult. While HCM is associated with a short QRS duration, left ventricular hypertrophy has been related to increased QRS durations but this association may vary across subtypes of left ventricular hypertrophy. We investigated the relationship between QRS duration and LV mass (LVM) in elite endurance athletes without history of cardiovascular disease.
Methods
Elite professional cyclists (n=108) underwent electrocardiographic and echocardiographic examinations as part of their routine care. Athletes were exercising six times per week for a total of 15 to 25 hours. Transthoracic echocardiography was performed following current guidelines using a portable ultrasound device (GE Vivid iq, M5Sc probe). LVM was determined using the Devereux equation and indexed to body surface area (LVMI). A 12-lead electrocardiogram (ECG) was recorded (SmartScript, Dr. Gerhard Schmidt GmbH) and QRS duration, axis and Sokolov-Lyon index were determined. Linear regression analyses were performed to assess the association of QRS duration with LVMI.
Results
Median QRS duration was 98 ms (interquartile range: 96-104 ms) and median LVMI was 155.8 g/m2 (interquartile range: 137-173 g/m2), indicating pronounced LV hypertrophy. 55 athletes (51 %) had QRS duration < 100 ms, while 47 (41 %) showed an incomplete right-bundle branch block (RBBB) (QRS duration: 100–119 ms). 6 individuals (6 %) exhibited a complete RBBB, as indicated by a QRS duration > 120 ms. A positive correlation of QRS duration and LVMI (r=0.22, p=0.023; 0.08 ms per 1 g/m2 increase in LVMI) was detected. QRS axis deviated to the left as LVMI increased (r=–0.21, p=0.032; –0.31 deg per 1 g/m2 increase in LVMI). The traditional Sokolov-Lyon-Index was found to be significantly associated with LVMI (r=0.25, p=0.0095; 0.01 mV per 1 g/m2 increase in LVMI).
Conclusion
In healthy endurance athletes, QRS duration associates positively with LVMI. These findings are in contrast to individuals with HCM who typically exhibit shortened QRS complexes as LVM increases. Evaluation of simple ECG parameters such as QRS duration may be helpful in differentiating various subtypes of left ventricular hypertrophy.
