Functional and metabolic imaging of the right ventricle: short-term caloric restriction increases myocardial triglyceride content and decreases diastolic heart function

Abstract

Background Caloric restriction increases plasma non-esterified fatty acid (NEFA) levels, and increases myocardial triglyceride content. It has been shown that elevated levels of NEFA’s in patients with metabolic disease (metabolic syndrome/ type 2 diabetes mellitus) are associated with a decrease in left ventricular function. However little is known about its effects on right ventricular function. Therefore, the purpose of the present study was to evaluate myocardial metabolic flexibility in relation to right ventricular diastolic function in healthy volunteers after short-term caloric restriction. Methods Measures were performed in 14 healthy subjects before and after 3 days of caloric restriction based on Modifast diet (500 kcal/day) using cardiovascular magnetic resonance imaging (MRI). Myocardial triglyceride (TG) content was measured in the interventricular septum using navigator gated, proton MR spectroscopy. After water suppression, myocardial TG content was quantified as a percentage of the unsuppressed water signal. Right ventricular diastolic function was measured using MR velocity mapping across the tricuspid valve. Early (E) deceleration rate was quantified and regarded as representative for right heart diastolic function. Results