The Impact of Altered Arterioventricular Coupling on Central Cardiovascular Energy Delivery

This study will assess the amount of energy that the heart will deliver to the central circulation and the efficiency of that energy transfer, in patients undergoing a coronary artery bypass graft operation. Measurements will be taken just after induction of anaesthesia and repeated just after the end of the operation. The total energy delivered by the heart will be calculated by multiplying a pressure curve from the artery in the hand with the instantaneous ultrasound recorded cardiac output flow curve. The energy responsible for the acceleration of the blood volume, known as oscillatory power will also be calculated. The energy transfer will be calculated using a mathematical model based upon other ultrasound and blood pressure recorded variables. We would like to see if any alteration in energy delivered is in part due to impairment in energy transfer or alteration of fraction of oscillatory power rather than a change in total energy production. We would also like to study if there are changes in the oscillatory power after cardiac bypass surgery. The patients will be sampled sequentially into the study. We are not aware of any such studies undertaken in humans previously.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases

• Study Type: Observational
• Enrollment (Actual): 41

Contacts and Locations

Study Locations

• Norway
  • Trondheim, Norway
    • St Olavs hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

The population undergoing elective coronary artery bypass grafting typically have multiple cardiovascular risk factors such as hypertension, hyperlipidaemia, diabetes and smoking.

Description

Inclusion Criteria:

• Elective Coronary Artery Bypass Graft patients
• No contraindications to transoesophageal Echo
• Ejection fraction 40% or over

Exclusion Criteria:

• Lack of consent
• Emergency operation
• Prosthetic aortic valve

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Arterioventricular coupling	The ratio between arterial elastance and ventricular elastance	1 day
Total Cardiac Power	The amount of energy per second delivered from the left ventricle to the arterial circulation	1 day
Oscillatory Cardiac Power	The part of total cardiac power which is responsible for acceleration of the blood volume during systole.	1 day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cardiac Output	The hearts delivery of volume per minute	1 day
Heart rate	The amount of heart beats per minute	1 day
Systemic vascular resistance	The resistance to flow of the arterial tree	1 day

Collaborators and Investigators

• Sponsor: Norwegian University of Science and Technology
• Collaborators: St. Olavs Hospital
• Investigators: Principal Investigator: Idar Kirkeby-Garstad, md phd, Norwegian University of Science and Technology

Study record dates

Study Major Dates

• Study Start (Actual): January 2, 2019
• Primary Completion (Actual): March 13, 2019
• Study Completion (Actual): March 13, 2019

Study Registration Dates

• First Submitted: August 31, 2018
• First Submitted That Met QC Criteria: August 31, 2018
• First Posted (Actual): September 4, 2018

Study Record Updates

• Last Update Posted (Actual): March 21, 2019
• Last Update Submitted That Met QC Criteria: March 19, 2019
• Last Verified: March 1, 2019

More Information

Terms related to this study

• Keywords: Coronary Artery Bypass Graft; Cardiac Power; Oscillatory Power; Arterioventricular Coupling
• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: 2017/767

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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