| Autor: |
Lanfranconi F; 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.; 2 Foundation Monza and Brianza for the Mother and Her Child, Monza, Italy., Ferri A; 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.; 3 Institute for Health and Sport, Victoria University, Melbourne, Australia., Pollastri L; 4 PENTAVIS, Laboratory of Sport Medicine, Lecco, Italy., Bartesaghi M; 4 PENTAVIS, Laboratory of Sport Medicine, Lecco, Italy., Novarina M; 4 PENTAVIS, Laboratory of Sport Medicine, Lecco, Italy., De Vito G; 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy., Beretta E; 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy., Tremolizzo L; 1 School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy. |
| Abstrakt: |
Harness hang syncope (HHS) is a risk that specifically affects safety of harness users in mountain climbing. Aims: To evaluate individual patterns of breathing resulting from deranged cardiovascular reflexes triggering a syncopal event when a mismatch between cerebral O 2 demand and supply is present. Results: Forty healthy participants [aged 39.1 (8.2) years] were enrolled in a motionless suspension test while hanging in harness. Respiratory gas exchange values were analyzed to assess the pattern of breathing (EpInW el , respiratory elastic power) and cardiovascular parameters were monitored (BP, blood pressure). Four participants experienced HHS after 30.0 (7.6) minutes, with an early manifestation of loss of control of both a sustainable EpInW el and BP, starting after 10-12 minutes. Among the other participants, two different reactions were observed during suspension: (1) group G1 tolerated 32.7 (11.4) minutes of suspension by a favorable adaptation of the EpInW el and BP parameters and (2) group G2 showed significantly shorter time of suspension 24.0 (10.4) minutes with unfavorable increase in EpInW el and BP. Conclusions: Greater resistance to HHS occurs in people developing less marked fluctuations of both respiratory and cardiovascular reflex responses. Conversely, wider fluctuations both in control of EpInW el and BP were observed in the event of decreased suspension tolerance or in syncopal events. |
