Impact of Prolonged Cold-water Swimming on Heart Rate and Cardiac Function

Completed

• Conditions: Hypothermia

• Registration Number: NCT06296290
• Lead Sponsor: University Hospital, Caen

Brief Summary

A significant medical risk associated with hypothermia during exercise in a cold environment cardiac arrhythmia due to a possible autonomic conflict. However, little is known about the changes in heart rate and cardiac function after prolonged cold water swimming.

The investigators propose to measure the changes in core temperarure during and after a cold water swim at at a water temperature below 15.5°C qualifying for English Channel swim and to test the association with changes in heart rate variability, resting electrocardiogram and left ventricle function.

Detailed Description

Not available

Study Timeline

• Study Start: 2022-06-04
• Primary Completion: 2022-06-06
• Study Completion: 2022-08-15
• Status Verified: 2024-02
• Study First Submitted: 2024-02-29
• Study First Submitted QC: 2024-02-29
• Last Update Submitted: 2024-02-29
• Study First Posted: 2024-03-06
• Last Update Posted: 2024-03-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• swimmers taking part in the Channel Swim Camp
• swimmers above 18 years of age
• swimmers willing and able to give informed consent for participation in the study

Exclusion Criteria

• swallowing disorder
• chronic gastrointestinal disease
• MRI scheduled within 48 hours after the race.
• known cardiac arythmia or cardiovascular disease

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Heart rate from a resting ECG recording	Two Time points (1) the day before the race and (2) at 30 min after ending the race	Waves, intervals \& segments of the normal ECG trace was collected
Heart rate from a 5-minute ECG recording	Two Time points (1) the day before the race and (2) at 30 min after ending the race	Heart rate variability (HRV) parameters including time-domain measures and frequency-time measures
Change in Body Core Temperature	Time Frame: Continuous measurement was collected from 30 minutes before the race until 2 hours after the end of the race for each swimmer]	Measurement of Body Core Temperature using an ingestible electronic sensor (e-Celsius®, BodyCap , Caen, France) which provide a continuous validated measurement
Transthoracic echocardiography (TTE) analysis	Two Time points (1) the day before the race and (2) at 30 min after ending the race	Left and right ventricular and atrial dimensions, and systolic and diastolic ventricular function assessment were collected

Secondary Outcome Measures

Name	Time	Method
Body composition, fat-free mass	One measurement assessed the day before the race	Fat-free mass (in kg, % of body mass \[fat-free mass and body mass were combined to report % of body mass) was measured using bioelectrical impedance analysis (mBCA 525, Seca, Germany).
Individual characteristics, gender	One evaluation assessed the day before the race	The variable collected was the gender of participants
Body composition, body fat mass	One measurement assessed the day before the race	Fat mass (in kg, % of body mass \[fat mass and body mass were combined to report % of body mass) was measured using bioelectrical impedance analysis (mBCA 525, Seca, Germany).
Individual characteristics, age	One evaluation assessed the day before the race	The variable collected was the age of participants
Duration	The duration of swimming was collected from the organisers immediately after the race	Duration of the swimming
Individual characteristics, training in cold environment	One evaluation assessed the day before the race	The variable collected was the type of specific training in cold environment (yes/no)

Trial Locations

Locations (1)

CHU Caen Normandie; 🇫🇷 Caen, France