Low QRS voltage in Paralympic athletes: An unexpectedly high prevalence

BACKGROUND: Low QRS voltage (LQRSV) is an uncommon electrocardiographic finding in able-bodied athletes and it is investigated to exclude underlying cardiomyopathy. Its prevalence and clinical meaning in Paralympic athletes (PA), particularly those with spinal cord injury (SCI), remain unknown. OBJECTIVES: To describe the prevalence of LQRSV in elite PA and to explore its associations with cardiac structure and functional parameters, with attention to differences between athletes with and without SCI. METHODS: 193 healthy Olympic PA underwent anthropometric assessment, 12‑lead-ECG, comprehensive echocardiography, and cardiopulmonary exercise testing. Athletes were classified according to disability (SCI vs. non-SCI). LQRSV was defined according to international criteria. RESULTS: PA had mean age 32.7 ± 9.7 years, and 44% were females. LQRSV was identified in 22 athletes (11.4%), with a higher prevalence among those with SCI (27.6% vs. 4.6% in NSCI, p < 0.0001). Athletes with LQRSV were older (p = 0.01), frequently involved in skill-based sports (p < 0.0001). Compared with athletes with normal ECG voltages, they exhibited reduced exercise performance (VO2 max 23.1 ± 10.5 vs. 37 ± 14.5 mL/min/kg; p < 0.0001) and lower O2 pulse (p < 0.0001). Echocardiography revealed smaller left ventricular (LV) volumes and LV mass, while systolic function was preserved (p = 0.488). Among SCI athletes, those with LQRSV demonstrated lower W/kg (p = 0.039), lower LV mass (p = 0.037) and higher fat mass (p = 0.035). At multivariable logistic regression analysis, SCI emerged as the only independent correlate of LQRSV (p = 0.011). CONCLUSIONS: LQRSV shows an unexpectedly high prevalence in PA, particularly those with SCI, and may reflect a cardiac phenotype characterized by smaller chambers and reduced metabolic drive, rather than pathological remodeling.