03 May 2026
: Case report 
An Unexpected Cause of Marathon Dyspnea: A Diagnostic Challenge in an Amateur Athlete
Challenging differential diagnosis
Martyna Świerkowska ABDEF 1*, Małgorzata Kurpaska
ADEF 2, Paweł Krzesiński ADE 2, Katarzyna Piotrowicz ADE 2
DOI: 10.12659/AJCR.951838
Am J Case Rep 2026; 27:e951838
Table 1 Summary of results from 3 CPET tests.
| CPET 1 | CPET 2 | CPET 3 | |
|---|---|---|---|
| Date | 03.01.2025 | 22.05.2025 | 10.07.2025 |
| Protocol | ramp 0 watt – 224 watts of cycle ergometer | ramp 7–13.0 km/h of treadmill | ramp 7–14.1 km/h of treadmill |
| Peak VO | 34 ml/min/kg, 104% of the predicted value | 42 ml/min/kg, 127% of the predicted value | 47 ml/min/kg, 143% of the predicted value |
| Peak HR | 177 bpm, 118% of the predicted value | 192 bpm, 128% of the predicted value | 181 bpm, 122% of the predicted value |
| Peak BP | 218/96 mmHg | 177/81 mmHg | 244/65 mmHg |
| RER | 1.07 | 1.08 | 1.12 |
| Time of exercise | 12 min | 9 min 18 seconds | 11 min |
| VE/VCO slope | 34.2 | 43.3 | 37.9 |
| VO at AT [%pred.] | 18 ml/min/kg, 55% of the predicted value | 32 ml/min/kg, 96% of the predicted value peakVO | 34 ml/min/kg, 103% of the predicted value peakVO |
| AT – anaerobic threshold; BP – blood pressure; HR – heart rate; RER – respiratory exchange ratio; VE/VCO slope – ventilatory efficiency index; VO – oxygen uptake. | |||