VAN DE Sande DAJP; Schoots T; Hoogsteen J; Doevendans PA; Kemps HMC;

Medicine And Science In Sports And Exercise [Med Sci Sports Exerc] 2019 Jan; Vol. 51 (1), pp. 12-18.

Purpose: The clinical relevance of abnormal exercise testing (ET) results (at least 0.1 mV ST segment depression measured during exercise or recovery in three consecutive beats) in athletes without obstructive coronary artery disease (CAD) is not well understood. It is unknown whether this phenomenon reflects a physiological adaptation to sport or a truly ischemic response and a concomitant attenuated stroke volume (SV) response. The aim of this study was to investigate if athletes with abnormal ET results without obstructive CAD showed signs of an attenuated SV response using cardiopulmonary ET parameters.
Methods: A total of 78 male master athletes with abnormal ET results without obstructive CAD underwent cardiopulmonary ET. ΔO2 pulse/Δwork rate (WR), ΔV˙O2/ΔWR, and Δheart rate (HR)/ΔWR were assessed and compared with data from 78 male master athletes with normal ET results, matched for age, sports characteristics, and exercise capacity.
Results: The ΔO2 pulse/ΔWR ratio beyond anaerobic threshold in athletes with abnormal ET results was lower than that in athletes with normal ET results (0.73 ± 0.41 vs 1.12 ± 0.54, respectively, P < 0.001). The ΔV˙O2/ΔWR ratio was also lower in athletes with abnormal ET results (0.9 ± 0.2 vs 1.0 ± 0.3, respectively, P = 0.041). Furthermore, these athletes showed a greater increase in HR in the last 2 min of exercise (ΔHR/ΔWR ratio: 1.19 ± 0.5 vs 0.80 ± 0.6, P < 0.001).
Conclusion: Athletes with abnormal ET results without obstructive CAD showed an attenuated O2 pulse slope, decreased ΔV˙O2/ΔWR ratio, and increased ΔHR/ΔWR ratio beyond anaerobic threshold when compared with athletes with a normal ET result. These results support the hypothesis that at least a part of the athletes with an abnormal ET in absence of obstructive CAD have an attenuated SV response at high-intensity exercise.