Metabolic syndrome associates with left atrial dysfunction

Background and aims: Obesity and metabolic syndrome (MetS) are risk factors of atrial fibrillation (AF), but limited data exist on their effect on left atrial (LA) function. The aim of the study was to evaluate the effects of cardiac, hepatic and intra-abdominal ectopic fat depots and cardiometabolic risk factors on LA function in non-diabetic male subjects. Methods and results: Myocardial and hepatic triglyceride contents were measured with 1.5T H-1-magnetic resonance spectroscopy and LA and left ventricular function, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), epicardial and pericardial fat by magnetic resonance imaging (MRI) in 33 men with MetS and 40 men without MetS. LA volumes were assessed using a novel three-chamber orientation based MRI approach. LA ejection fraction (EF) was lower in MetS patients than in the control group (44 +/- 7.7% in MetS vs. 49 +/- 8.6% in controls, p = 0.013) without LA enlargement, indicating LA dysfunction. LA EF correlated negatively with waist circumference, body mass index, SAT, VAT, fasting serum insulin, and homeostasis model assessment of insulin resistance index, and positively with fasting serum high-density lipoprotein cholesterol. VAT was the best predictor of reduced LA EF. Conclusions: MetS associates with subclinical LA dysfunction. Multiple components of MetS are related to LA dysfunction, notably visceral obesity and insulin resistance. Further studies are needed to elucidate the role of mechanical atrial remodeling in the development of AF. (C) 2018 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.Peer reviewe

Boganmeldelser

Book review

Pathology and Cardiotoxicity of the Epicardial Adipose Tissue

Intra-organ fatty infiltration is associated with end-organ damages and increased cardiovascular risk. Ectopic fat deposition occurs also within the heart and may cause a metabolic cardiomyopathy. Epicardial fat (EAT) can be considered ectopic fat accumulation of the heart. Epicardial fat and intra-myocardial triglycerides content are related. Excessive EAT can produce lipotoxic effects throughout an abnormal lipid deposition and fatty infiltration in the myocardium. As cardiomyocytes fat storage capacity is very limited, high levels of plasma lipids cause cardiac steatosis, hypertrophy, dysfunction, and ultimately failure, as observed in morbid obesity and uncontrolled diabetes. Due to its anatomical and functional vicinity to the myocardium, EAT can affect the morphology and function of all of the heart chambers. Increased epicardial fat has been largely associated with increased left ventricular mass, abnormal geometry, enlarged atria, and diastolic dysfunction. Multifactorial physical and biomolecular mechanisms can explain the effects of excessive EAT on the heart