Myocardial steatosis impairs left ventricular diastolic–systolic coupling in healthy humans

Autor: Andrew P. Oneglia, Lidia S. Szczepaniak, Manall F. Jaffery, Daisha J. Cipher, Jeffrey G. McDonald, Mark J. Haykowsky, Kerrie L. Moreau, Deborah J. Clegg, Vlad Zaha, Michael D. Nelson
Rok vydání: 2023
Předmět:
Zdroj: J Physiol
ISSN: 1469-7793
0022-3751
DOI: 10.1113/jp284272
Popis: Mounting evidence suggests that myocardial steatosis contributes to left ventricular diastolic dysfunction, but definitive evidence in humans is lacking due to confounding comorbidities. As such, we utilized a 48-hour food restriction model to acutely increase myocardial triglyceride (mTG) content – measured by (1)H magnetic resonance spectroscopy – in 27 young healthy volunteers (13 men/14 women). Forty-eight hours of fasting caused a more than 3-fold increase in mTG content (p < 0.001). Diastolic function – defined as early diastolic circumferential strain rate (CSRd) – was unchanged following the 48-hour fasting intervention, but systolic circumferential strain rate was elevated (p < 0.001), indicative of systolic-diastolic uncoupling. Indeed, in a separate control experiment in 10 individuals, administration of low-dose dobutamine (2 μg/kg/min) caused a similar change in CSRs as was found during 48-hour of food restriction, along with a proportionate increase in CSRd, such that the two metrics remained coupled. Taken together, these data indicate that myocardial steatosis contributes to diastolic dysfunction by impairing diastolic-systolic coupling in healthy adults, and suggest that steatosis may contribute to the progression of heart disease.
Databáze: OpenAIRE
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