Impact of Gravity on Cardiac Hemodynamics

Healthy Clinical Trial

— ACUITY  

Official title:

Effect of Intra-cardiac Hydrostatic Pressure Gradient in Cardiac Filling and Ejection

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06190756
• Other study ID #: 23-0077
• Status: Recruiting
• Phase: N/A
• Start date: November 22, 2023
• Est. completion date: January 15, 2025

Study information

• Verified date: November 2023
• Source: University Hospital, Caen
• Contact: Amir HODZIC, MD PhD
• Phone: 0231065503
• Email: hodzic-a[@]chu-caen.fr
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The goal of this clinical trial is to define and compare pre-load dependance of the cardiac function according to the intracardiac hydrostatic gradient of pressure in healthy and diabetic populations. Participants will undergo 4 tilt angle and 4 lower body negative pressure intensities during which cardiovascular data will be assessed and a transthoracic echography will be performed.

Description:

Gravitational force affects both the cardiac mass and the thoracic compartment. However, few studies in humans have explored whether the relationship between cardiac function and load-dependence varies according to the orientation of the heart in space (e.g. between the upright and supine positions) and therefore according to gravitational stress. Thirty-two volunteers (16 healthy subjects and 16 subjects with type I diabetes) will be included in the study. Each subject will be analysed over half a day in the Inserm COMETE laboratory. Measurements of the intra-cardiac hydrostatic pressure gradient (reflecting gravitational force) and indicators of cardiac function will be analysed by transthoracic echocardiography using dedicated post-processing software. These measurements will be compared at identical pre-load on the basis of the relationship between thoracic impedance and angle of vertical inclination using a Tilt Test on the one hand and between thoracic impedance and Lower Body Negative Pressure (LBNP) depression in the supine position on the other. In the supine position, the echocardiogram will be repeated for each subject with different levels of intensity of preload decrease by LBNP up to a maximum of -50 torr, and compared with different angles of vertical inclination head up up to +80° on the Tilt Test. The study aims to compare the contribution of intra-cardiac hydrostatic force to cardiac filling and ejection mechanics in a population of healthy volunteers and subjects with diabetes. The goal is to define and compare the pre-load dependence of the cardiac function indices studied according to the anatomical supine posture with zero intra-cardiac hydrostatic gradient with the standing posture during which the hydrostatic force is expressed between the cardiac base and apex. The hypothesis is that cardiac filling and ejection are improved when the longitudinal axis of the heart is anatomically oriented in the standing position compared with the supine position, by restoring the intraventricular hydrostatic pressure gradient. Comparing a group of healthy subjects with a group of subjects with diabetes will enable to assess whether the dependence of cardiac function on the orientation of the heart in space is more marked in the presence of subclinical impairment of myocardial function.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 32
• Est. completion date: January 15, 2025
• Est. primary completion date: November 22, 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 40 Years

Eligibility

Inclusion Criteria:

• Affiliated to the social security system
• Patient informed of the study and having signed an informed consent form
• Type 1 diabetes for at least 10 years followed at Caen University Hospital, equipped with a continous glucose monitoring system

Exclusion Criteria:

• Trained athletes (= 6 hours of sustained physical exercise >70% VO2max per week for > 6 months)
• Chronic cardiovascular disease or cardiovascular treatment
• Personal history of chemotherapy and/or thoracic radiotherapy
• Cerebral and/or spinal disease
• Inclusion of the subject in another biomedical research protocol of interventional type (during the study or in the 3 months prior to inclusion)
• Pregnant, breast-feeding or parturient women
• Adults under legal protection (guardianship, curators) or unable to express their consent or deprived of their freedom

Related Conditions & MeSH terms

• Diabetes Mellitus, Type 1
• Diabetes type1
• Healthy

Intervention

Other:
• Cardiovascular and Baroreflex stimulation by Tilting
Tilt of the patient at 4 angles (22°, 42°, 58° and 80°), the order is randomized for 3 angles (22°, 42°, 58°) while 80° will always be last.
• Cardiovascular and Baroreflex stimulation by Lower Body Negative Pressure
The patient will undergo 4 level of LBNP (10Torr, 20Torr, 35Torr, 50Torr), the order is randomized for 3 intensities (10Torr, 20Torr, 35Torr) while 50Torr will always be last.

Locations

Country	Name	City	State
France	Inserm 1075 Comete, Unicaen	Caen

Sponsors (4)

Lead Sponsor	Collaborator
University Hospital, Caen	CNRS UMR 5220 INSERM U1294 CREATIS ,Université Lyon 1, INSA Lyon, France, INSERM UMR-S 1075 COMETE, Caen, France, Jozef Stefan Institute

Country where clinical trial is conducted

France, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Heart rythme	continuous electrocardiogram monitoring for assessing the variation of heart frequency	baseline, during the intervention
Primary	Arterial blood pressure	continuous central arterial pressure monitoring using Finapress	baseline, during the intervention
Primary	thoracic Impedancemetry	estimation of body fluid variation as a surrogate of prelaod	baseline, during the intervention
Primary	Echocardiography	non invasive diastolic intraventricular pressure gradient	baseline, during the intervention