Prevalence and clinical significance of T-wave inversion on electrocardiogram in patients with exercise-induced laryngeal obstruction (EILO): A cross-sectional study

AIMS: We aimed to systematically evaluate standard 12‑lead electrocardiograms (ECG) in young individuals with exercise-induced laryngeal obstruction (EILO), with a special focus on the prevalence and clinical significance of T-wave inversion (TWI). METHODS AND RESULTS: 235 individuals (mean age 16.7 years, 85% females) presenting to the EILO Clinic, underwent 709 high-intensity cardiopulmonary exercise treadmill testing with continuous visualization of the larynx (CLE- Continuous Laryngoscopy Exercise). There was no adverse event during exercise tests. The prevalence of TWI (negatively deflected T-wave ≥1 mm (0.1 mV amplitude) in any 2 contiguous leads excluding aVR, III, and V1) was 42.6% (18.7% isolated in the inferior wall leads, 13.2% in the inferolateral leads, 5.1% in both the inferior and anterior leads, 3% both in the inferior and anteroseptal leads, 2.1% isolated in anteroseptal leads and 0.9% isolated in anterior wall leads). Age, body height and weight, exercise duration and peak oxygen uptake did not differ between individuals with versus without TWI (all p > 0.05). There was a trend towards lower total CLE score in individuals with TWI (4.2 vs 4.5, p = 0.070). Individuals with TWI had higher resting heart rate (98 vs 95 bpm, p = 0.05), shorter PQ-interval (124 vs 129 ms, p = 0.020) and achieved higher peak heart rate (193 vs 189 bpm, p = 0.005) and metabolic equivalents during exercise (13.4 vs 12.9, p = 0.028). CONCLUSIONS: High-intensity CLE-test in individuals with EILO was not associated with any adverse cardiac findings. TWI was highly prevalent and particularly observed in the inferior or inferolateral wall leads but had no association with energetic decline or cardiac dysfunction.