Vittorio Emanuele Bianchi, MD
Nei pazienti con malattie cardiovascolari, la corretta alimentazione ha un effetto determinante sulla funzione del cuore. In particolare, nei malati di scompenso cardiaco la dieta dovrebbe essere leggermente più alta di calorie e con un basso apporto di grassi e alto apporto di carboidrati. Il cuore ischemico infatti, non utilizza più i grassi che anzi sono dannosi al miocardio, ma prevalentemente i carboidrati. Inoltre in questi pazienti la perdita di peso è correlata con il rischio di mortalità.
Abstract: Themetabolic sources of energy for myocardial contractility include mainly free fatty acids (FFA) for 95%, and in lesser amounts for 5% from glucose and minimal contributions from other sub-strates such lactate, ketones, and aminoacids. However, myocardial efficiency is influenced by metabolic condition, overload, and ischemia. During cardiac stress, cardiomyocytes increase glucose oxidation and reduce FFA oxidation. In patients with ischemic coronary disease and heart failure, the low oxygen availability limits myocardial reliance on FFA and glucose utilization must increase. Although glucose uptake is fundamental to cardiomyocyte function, an excessive intracellular glucose level is detrimental. Insulin plays a fundamental role in maintaining myocardial efficiency and in reducing glycemia and inflammation; this is particularly evident in obese and type-2 diabetic patients. An excess of F availability increase fat deposition with in cardiomyocytes and reduces glucose oxidation. In patients with high body mass index, a restricted diet or starvation have positive effects on cardiac metabolism and function while, in patients with low body massi ndex, restrictive diets, or starvation have a deleterious effect. Thus, weight loss in obese patients has positive impacts on ventricular mass and function, whereas, in under weight heart failure patients, such weight reduction adds to the risk of heart damage, predisposing to cachexia. Nutrition plays an essential role in the evolution of cardiovascular disease and should be taken into account. An energy-restricted diet improve smyocardial efficiency but can represent a potential risk of heart damage, particularly in patients affected by cardiovascular disease. Micronutrient integration has a marginal effect on cardiovascular efficiency.(Curr Probl Cardiol2018;00:130.)
Energy Metabolism and Heart Function
The cardiomyocyte is a unique muscle cel lwhich possesses the ability to maintain contractile function under varying metabolic conditions.