Related Experiment Video
Updated: Jan 17, 2026
Surgically Induced Cardiac Volume Overload by Aortic Regurgitation in Mouse
Published on: August 30, 2022
The Effect of Body Size and Obesity on Cardiovascular Haemodynamics and Myocardial Mechanics
Christine M Madronio1, Shahab Pathan2, Gary K K Low3
1Nepean Clinical School, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia; Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia.
Insights
Obesity increases cardiac output and stroke volume due to cardiac remodeling. This study used cardiac MRI to show obesity impairs subclinical cardiovascular disease markers, specifically atrial strain.
Area of Science:
- Cardiology
- Radiology
- Metabolic Syndrome Research
Background:
- Growing obesity rates necessitate understanding early cardiac effects.
- Echocardiography faces challenges in obese individuals; cardiac MRI offers an alternative.
- Investigating body size impact on cardiac output (CO) and cardiovascular disease biomarkers is crucial.
Purpose of the Study:
- To assess the effect of body size on cardiac output (CO) and early cardiac imaging biomarkers.
- To utilize cardiac magnetic resonance imaging (CMR) for evaluating cardiovascular haemodynamics and myocardial mechanics in relation to body size.
Main Methods:
- Recruited healthy volunteers and individuals with obesity undergoing bariatric surgery.
- Utilized cardiac magnetic resonance imaging (CMR) to measure CO, stroke volume, heart rate, chamber volumes, and myocardial strain.
- Analyzed relationships between cardiovascular variables and body size metrics (BMI, BSA).
Main Results:
- Positive linear relationships found between CO and BMI/BSA (p<0.01).
- Stroke volume showed similar trends with BSA and BMI (p<0.01).
- Significant differences in left and right atrial strain observed; associations found between strain parameters and BMI/BSA.
Conclusions:
- Obesity is linked to increased cardiac output (CO) driven by cardiac remodeling and elevated stroke volume.
- Obesity is associated with impaired subclinical cardiovascular disease markers, particularly evident in multichamber strain analysis.
Background:
To improve management of cardiovascular-kidney-metabolic syndrome, a better understanding of the early effects of body size on the heart is crucial and remains under investigation, considering the increasing global prevalence of obesity. Most data available on cardiovascular haemodynamics come from echocardiography despite the known challenges in image acquisition in the context of overweight and obesity. Using cardiac magnetic resonance imaging, we aimed to further investigate the effect of body size on cardiac output (CO) and other early imaging biomarkers of cardiovascular disease.
Method:
Participants including healthy volunteers and individuals with obesity who were planning to undergo bariatric surgery were recruited from two completed studies. The participants underwent cardiac magnetic resonance imaging. Measures of cardiovascular haemodynamics and myocardial mechanics were collected, including CO, stroke volume, heart rate, chamber volumes, and myocardial strain. The relationship of these variables with body size were assessed.
Results:
A total of 57 participants were recruited (79% female; mean age, 41 years). A positive linear relationship was observed between CO vs body mass index (BMI) (p<0.01) and body surface area (BSA) (p<0.01). A similar trend was seen with stroke volume vs BSA (p<0.01) and BMI (p<0.01). Indexation to BSA rendered chamber volumes similar. We found significant differences in left and right atrial strain between the groups. Regression analysis demonstrated an association between left ventricular global longitudinal strain and right atrial strain with BSA and between left ventricular global longitudinal strain, right ventricular free wall strain, and right atrial strain with BMI.
Conclusions:
Obesity is associated with increased CO; this increase is a result of cardiac remodelling and consequent increase in stroke volume. Obesity is associated with an impairment of subclinical markers of cardiovascular disease measured using multichamber strain.
Related Concept Videos
01:29Pathophysiology of Cardiac Performance
01:29Heart Failure II: Pathophysiology
01:22Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
01:26Imbalances in Cardiac Output
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send...
01:21Drug Dosing: Obese Patients
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart...