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Into the Blue: First in Man Data on Diving Physiology in Fontan Patients
C Paech1, R A Gebauer2, M Weidenbach2
1Department for Pediatric Cardiology, University of Leipzig - Heart Center, Strümpellstr. 39, 04289, Leipzig, Germany. christian.paech@medizin.uni-leipzig.de.
Insights
This study found that patients with univentricular hearts after Fontan palliation can tolerate apnea diving similarly to healthy individuals. This suggests current guidelines restricting these activities may be overly cautious.
Area of Science:
- Cardiology
- Sports Medicine
- Physiology
Background:
- Current guidelines restrict swimming and diving for Fontan patients due to assumed reduced physiological capacity.
- These restrictions are based on expert consensus rather than empirical data.
- Previous studies showed no adverse events during immersion, but not submersion or apnea diving.
Purpose of the Study:
- To evaluate the physiological effects of submersion and apnea diving in patients with univentricular hearts post-Fontan palliation.
- To compare the physiological responses of Fontan patients and healthy controls during a standardized diving protocol.
Main Methods:
- A standardized diving protocol including static and dynamic apnea phases was administered.
- Physiological data were recorded for both Fontan patients and a control group of healthy adults.
- Participants were recruited from the Heart Center Leipzig, Department of Pediatric Cardiology.
Main Results:
- No adverse events occurred during the diving protocol in either group.
- The physiological responses to diving appeared comparable between Fontan patients and healthy controls.
- Healthy individuals demonstrated superior performance, but fundamental physiological adaptation mechanisms were similar.
Conclusions:
- Apnea diving appears physiologically tolerable for Fontan patients.
- The findings challenge current restrictive guidelines, suggesting a need for reassessment based on empirical data.
- Further research may refine understanding of safe participation in water-based recreational activities for this patient group.
Abstract:
Swimming and diving are popular recreational activities. As congenital heart disease, especially patients with univentricular hearts after Fontan palliation are thought to have reduced physiologic capacities for compensation of submersion-associated physiologic demands, current guidelines put restraints on this group of patients. Although these restrictions on doctoral advice place a significant burden on affected patients, it is especially interesting that these guideline recommendations are merely based on physiologic assumptions, i.e., expert consensus. A recent study by Paech et al. presented the first in vivo data on the effects of immersion in Fontan patients, stating no major adverse events in their study group as well as comparable physiologic adaption as reported in the literature for healthy people. Yet, submersion was not reflected in this study, and the current study therefore aimed to conduct a first study for the evaluation of the effects of submersion and apnea diving in Fontan patients. A control group of healthy adults as well as patients recruited from the Heart Center Leipzig, Department of pediatric cardiology underwent a standardized diving protocol including a static as well as dynamic apnea phase. Physiologic data were recorded. This study presents the first structured data on diving physiology in Fontan patients compared to healthy probands. There were no adverse events. The physiologic response to diving seems to be comparable between healthy probands and Fontan patients. Although, healthy probands did reach a much better performance, the basic mechanisms of physiologic adaption seem comparable.
