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Updated: May 29, 2026

Measuring Cardiac Autonomic Nervous System (ANS) Activity in Children
Published on: April 29, 2013
SCUBA-dive-related changes in heart rate in children
Bernd E Winkler1, Kay Tetzlaff, Claus-Martin Muth
1Dept. of Anaesthesiology, University of Ulm, Germany.
Abstract:
The purpose of this study was to monitor heart rate (HR) and rhythm during open water SCUBA dives. Nine children performed 25-min open water SCUBA dives to 8 m depth. Before, during and after these dives, ECG was recorded. Compared with predive heart rate, heart rate declined by -24 ± 8% (range -36%; -15%) during the dive. In some children a further decline in HR was observed within the last minutes of the dive. Older and taller subjects and those with a high initial HR showed a more pronounced decline in HR. Furthermore singular supraventricular and ventricular extrasystoles were observed in some children. Immersion as well as facial and skin cooling presumably account for the initial decline in heart rate. A further drop in HR within the last minutes of the dive might be related to mild hypothermia. Single supraventricular and ventricular extrasystoles might occur in healthy children during dives.
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