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

Impact of Prolonged Cold-water Swimming on Heart Rate and Cardiac Function in Healthy Swimmers.

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.

Study Overview

• Status: Completed
• Conditions: Hypothermia

• Study Type: Observational
• Enrollment (Actual): 20

Contacts and Locations

Study Locations

• France
  • Caen, France, 14000
    • CHU Caen Normandie

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Probability Sample

Study Population

Swimmers participating in the 6-hour cold-water swim, qualifying for the English Channel swim at the Channel Swim Camp (Dinard, France).

Description

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 Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
All participants; The participants are the swimmers engaged in the 6-hour cold water swim during the Channel Swim Camp who volunteered to participate in the study.

What is the study measuring?

Primary Outcome Measures

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

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body composition, fat-free mass	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).	One measurement assessed the day before the race
Duration	Duration of the swimming	The duration of swimming was collected from the organisers immediately after the race
Individual characteristics, gender	The variable collected was the gender of participants	One evaluation assessed the day before the race
Individual characteristics, training in cold environment	The variable collected was the type of specific training in cold environment (yes/no)	One evaluation assessed the day before the race
Body composition, body fat mass	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).	One measurement assessed the day before the race
Individual characteristics, age	The variable collected was the age of participants	One evaluation assessed the day before the race

Collaborators and Investigators

• Sponsor: University Hospital, Caen
• Collaborators: INSERM UMR U1075 Comète GIP Cyceron, unicaen, Caen Normandie

Study record dates

Study Major Dates

• Study Start (Actual): June 4, 2022
• Primary Completion (Actual): June 6, 2022
• Study Completion (Actual): August 15, 2022

Study Registration Dates

• First Submitted: February 29, 2024
• First Submitted That Met QC Criteria: February 29, 2024
• First Posted (Estimated): March 6, 2024

Study Record Updates

• Last Update Posted (Estimated): March 6, 2024
• Last Update Submitted That Met QC Criteria: February 29, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Temperature Changes; Hypothermia
• Other Study ID Numbers: CARDIOCOLD

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No