Left ventricular mechanical dysfunction in diet-induced obese mice is exacerbated during inotropic stress: a cine DENSE cardiovascular magnetic resonance study

Autor: Christopher M. Haggerty, Linyuan Jing, Jonathan D. Suever, Andrea C. Mattingly, Brandon K. Fornwalt, Sage P. Kramer, Frederick H. Epstein, David K. Powell, Cassi M Binkley, Richard Charnigo
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Inotrope
Cardiac function curve
Male
medicine.medical_specialty
Cardiotonic Agents
Time Factors
Torsion
Mechanical
Magnetic Resonance Imaging
Cine
Stress
Diet
High-Fat
Ventricular Function
Left
Strain
Mice
Ventricular Dysfunction
Left
Predictive Value of Tests
Risk Factors
Stress
Physiological
Internal medicine
Dobutamine
medicine
Animals
Radiology
Nuclear Medicine and imaging
DENSE
Obesity
Infusions
Intravenous
Angiology
Medicine(all)
Ejection fraction
Radiological and Ultrasound Technology
medicine.diagnostic_test
business.industry
Research
Magnetic resonance imaging
Myocardial Contraction
3. Good health
Biomechanical Phenomena
Mice
Inbred C57BL
Disease Models
Animal
Endocrinology
Cardiology
Linear Models
Cardiovascular magnetic resonance
Stress
Mechanical
Cardiology and Cardiovascular Medicine
business
Diet-induced obese
Radial stress
medicine.drug
Zdroj: Journal of Cardiovascular Magnetic Resonance
ISSN: 1532-429X
1097-6647
Popis: Background Obesity is a risk factor for cardiovascular disease. There is evidence of impaired left ventricular (LV) function associated with obesity, which may relate to cardiovascular mortality, but some studies have reported no dysfunction. Ventricular function data are generally acquired under resting conditions, which could mask subtle differences and potentially contribute to these contradictory findings. Furthermore, abnormal ventricular mechanics (strains, strain rates, and torsion) may manifest prior to global changes in cardiac function (i.e., ejection fraction) and may therefore represent more sensitive markers of cardiovascular disease. This study evaluated LV mechanics under both resting and stress conditions with the hypothesis that the LV mechanical dysfunction associated with obesity is exacerbated with stress and manifested at earlier stages of disease compared to baseline. Methods C57BL/6J mice were randomized to a high-fat or control diet (60 %, 10 % kcal from fat, respectively) for varying time intervals (n = 7 – 10 subjects per group per time point, 100 total; 4 – 55 weeks on diet). LV mechanics were quantified under baseline (resting) and/or stress conditions (40 μg/kg/min continuous infusion of dobutamine) using cine displacement encoding with stimulated echoes (DENSE) with 7.4 ms temporal resolution on a 7 T Bruker ClinScan. Peak strain, systolic strain rates, and torsion were quantified. A linear mixed model was used with Benjamini-Hochberg adjustments for multiple comparisons. Results Reductions in LV peak longitudinal strain at baseline were first observed in the obese group after 42 weeks, with no differences in systolic strain rates or torsion. Conversely, reductions in longitudinal strain and circumferential and radial strain rates were seen under inotropic stress conditions after only 22 weeks on diet. Furthermore, stress cardiovascular magnetic resonance (CMR) evaluation revealed supranormal values of LV radial strain and torsion in the obese group early on diet, followed by later deficits. Conclusions Differences in left ventricular mechanics in obese mice are exacerbated under stress conditions. Stress CMR demonstrated a broader array of mechanical dysfunction and revealed these differences at earlier time points. Thus, it may be important to evaluate cardiac function in the setting of obesity under stress conditions to fully elucidate the presence of ventricular dysfunction. Electronic supplementary material The online version of this article (doi:10.1186/s12968-015-0180-7) contains supplementary material, which is available to authorized users.
Databáze: OpenAIRE
Externí odkaz: