IEEM-Heat and Heart Failure
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age45+
SponsorUniversity of Texas Southwestern Medical Center
About this trial
We will test the hypothesis that increasing skin wetness, and thus evaporative cooling, will attenuate the increase in core body temperature and accompanying cardiac stress during heat wave conditions in individuals with congestive heart failure. Secondly, we propose that wearing a water-saturated T-shirt will also be beneficial to attenuate the increase in core body temperature and accompanying cardiac stress during heat wave conditions in individuals with congestive heart failure. To accomplish these objectives, individuals with congestive heart failure and otherwise healthy control individuals will be exposed to the simulated heat wave condition (hot and dry) with the following cooling modalities: A) control trial (no limb immersion or skin wetting), B) skin wetting only trial, and C) water-saturated T-shirt trial in a randomized crossover fashion. Thermoregulatory and cardiovascular responses will be evaluated throughout these simulated heat wave exposures.
Primary outcomes variables will be skin and core temperatures, while secondary variables will include measures of cardiovascular stress, myocardial perfusion, heart rate, and echo-based measures of cardiac function.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Participants must be free of any significant underlying medical problems based upon a detailed medical history and physical exam, and normal resting electrocardiogram. Participants must be 45+ years.
Disqualifiers
Known heart disease; other chronic medical conditions requiring regular medical therapy including cancer, diabetes, neurological diseases, and uncontrolled hypertension, lung disease, etc.; as well as serious abnormalities detected on routine screening. Current smokers, as well as individuals who regularly smoked within the past 12 months, will be excluded. Subjects who cannot be age and gender matched to an individual in the heart failure group will be excluded.
Trial design
Design model
Crossover
Treatments tested in this trial
Control Trial
Other interventionAll participants will be exposed to a period of hyperthermia (hot and dry). In this condition, participants will not be given an experimental cooling modality.
Water-saturated T-shirt trial
Other interventionAll participants will be exposed to a period of hyperthermia (hot and dry). In this condition, participants will also wear a T-shirt that has been saturated with water.
Skin-Wetting Trial
Other interventionAll participants will be exposed to a period of hyperthermia (hot and dry). In this condition, participants will also be sprayed with water periodically.
Treatment groups
88 Participants
are divided into 2 treatment groupsGroup A: Individuals with Congestive Heart Failure (CHF)Active comparator 3 interventions
Group B: Individuals without Congestive Heart Failure (Control)Active comparator 3 interventions
Trial outcomes
Primary outcomes
1
Change in Core Body Temperature while wearing a water-saturated T-shirt
Core body temperature will be measured from gastrointestinal temperature via an ingestible telemetric pill or rectal temperature via telemetric pill suppository or rectal thermistor. Core body temperature will be measured at baseline as well as at the end of the hyperthermia simulation. The difference of those temperatures will reflect the change in core body temperature.
Time frame
Prior to and after each simulated heat wave exposure (approximately 210 minutes.)2
Change in Core Body Temperature in Skin-Wetting Trial
Core body temperature will be measured from gastrointestinal temperature via an ingestible telemetric pill or rectal temperature via telemetric pill suppository or rectal thermistor. Core body temperature will be measured at baseline as well as at the end of the hyperthermia simulation. The difference of those temperatures will reflect the change in core body temperature.
Time frame
Prior to and after each simulated heat wave exposure (approximately 210 minutes.)3
Change in Core Body Temperature in Control Trial
Core body temperature will be measured from gastrointestinal temperature via an ingestible telemetric pill or rectal temperature via telemetric pill suppository or rectal thermistor. Core body temperature will be measured at baseline as well as at the end of the hyperthermia simulation. The difference of those temperatures will reflect the change in core body temperature.
Time frame
Prior to and after each simulated heat wave exposure (approximately 210 minutes.)4
Change in Skin Temperature in while wearing a water-saturated T-shirt
Skin temperature will be measured from small temperature sensitive electrodes attached to the participant's skin. Skin temperature will be measured at baseline as well as at the end of the hyperthermia simulation. The difference of those temperatures will reflect the change in skin temperature.
Time frame
Prior to and after each simulated heat wave exposure (approximately 210 minutes.)Secondary outcomes
1
Change in Heart Rate while wearing a water-saturated T-shirt
Heart rate will be measured from ECG electrodes attached to the participant. Heart rate will be measured at baseline as well as at the end of the hyperthermia simulation. The difference of those heart rates will reflect the change in heart rate.
Time frame
Prior to and after each simulated heat wave exposure (approximately 210 minutes.)2
Change in Heart Rate in Skin-Wetting Trial
Heart rate will be measured from ECG electrodes attached to the participant. Heart rate will be measured at baseline as well as at the end of the hyperthermia simulation. The difference of those heart rates will reflect the change in heart rate.
Time frame
Prior to and after each simulated heat wave exposure (approximately 210minutes.)3
Change in Heart Rate in Control Trial
Heart rate will be measured from ECG electrodes attached to the participant. Heart rate will be measured at baseline as well as at the end of the hyperthermia simulation. The difference of those heart rates will reflect the change in heart rate.
Time frame
Prior to and after each simulated heat wave exposure (approximately 210minutes.)4
Rate Pressure Product while wearing a water-saturated T-shirt
Rate Pressure Product is calculated by multiplying Systolic Blood Pressure and Heart Rate.
Time frame
At the end of each heat wave exposure. Approximately 210minutes after the start of the heat wave simulation.Sponsors and contacts
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Source ClinicalTrials.gov