A Java software for calculating mean breath-by-breath variability in gas exchange parameters: application in young cardiac patients with exercise-related periodic breathing

Exercise oscillatory ventilation during autonomic blockade in young athletes and healthy controls

PURPOSE

Exercise oscillatory ventilation (EOV) is a form of periodic breathing that is associated with a poor prognosis in heart failure patients, but little is known about EOV in other populations. We sought to provide insights into the phenomenon of EOV after it was observed in young healthy subjects, including athletes, after the administration of dual autonomic blockade (DAB).

METHODS

From 29 participants who completed cardiopulmonary exercise testing (CPET) with and without DAB (0.04 mg/kg atropine and 0.2 mg/kg metoprolol), 5 subjects developed EOV (age = 29 ± 5 years; 3/5 were athletes) according to American Heart Association criteria. For each case, we identified 2 non-EOV healthy controls (age = 34.2 ± 8.3; 7/10 were athletes) that were subsequently age- and sex-matched.

RESULTS

No participants had EOV during exercise without DAB. The 5 participants (4 male, 1 female) who demonstrated EOV with DAB had lower mean tidal volume (1.7 ± 0.5 L/min vs. 1.8 ± 0.5 L/min; p = 0.04) compared to participants in the non-EOV group and a decrease in peak tidal volume (2.9 ± 0.6 L/min to 2.2 ± 0.7 L/min; p = 0.004) with DAB. There were few other differences in CPET measures between EOV and non-EOV participants, although the PETCO2 tended to be higher in the EOV group (p = 0.07).

CONCLUSION

EOV can be elucidated in young healthy subjects, including athletes, during cardiopulmonary exercise testing, suggesting that it may not be an ominous sign in all populations.

An overview of the applied definitions and diagnostic methods to assess exercise oscillatory ventilation--a systematic review

The variable "exercise oscillatory ventilation" (EOV), assessed during cardiopulmonary exercise test (CPET), recently became a fundamental prognostic parameter in patients with heart failure. In literature, various definitions are suggested, but an uniformly accepted description to identify EOV still lacks. We performed a systematic review of the literature in order to determine the different definitions and diagnostic techniques to assess EOV. A systematic search strategy was established and executed in seven databases (PubMed, Google Scholar, Cochrane Clinical Trials, Science Direct, Pedro, Web Of Science library and Medline (Ovid)) resulting in 605 citations after de-duplication. Full-text articles (n=124) were assessed for eligibility, resulting in 75 citations. The review accounted 17,440 patients of whom 4,638 subjects presented EOV. Seven studies described EOV in a non-heart failure population accounting 168 EOV subjects. The definitions could be categorized in nine subdivisions of which four (n=43) referred to an original description. The other subdivisions were combinations of the original definitions (n=11), quantifications (n=4), computational (n=3), vaguely described (n=8) or not defined (n=6). Symptom limited maximal exercise tests were conducted to assess EOV, however the modes, protocols, software and data sampling were divers. Heterogeneity in the numerous definitions to identify EOV and the vaguely described assessment methods are hindering the evolution to a standardized uniformly accepted definition and technique to identify this abnormal breathing pattern. Unity in definition and international adopted assessment is warranted to strengthen its validity as a prognostic marker and could promote communication. It may facilitate clinical trials on pathophysiology and origin of EOV.