Biochemical and hemodynamic changes in the hypertrophied dog heart subjected to chronic protein-calorie malnutrition.

Abstract

Biochemical and hemodynamic changes were assessed in 13 dogs subjected to sub-coronary valvular aortic stenosis and chronic protein-calorie malnutrition (PCM). Red blood cell, hemoglobin, serum albumin, free fatty acids, blood glucose, cholinesterase and blood amino acid levels were measured. The dynamic geometry of the left ventricle (LV) was assessed with chronically implanted sonomicrometric piezoelectric crystals. Cardiac function was evaluated by mean velocity of circumferential fiber shortening (mean VcF) and the relationship between LV end-systolic pressure (LVESP) or LV wall stress (LVWst) and LV end-systolic diameter (LVESD). The following results were obtained : 1) A decrease in body weight and increases in free fatty acids and 3-Methylhistidine were observed following long-term PCM. 2) Mean VcF was not depressed in dogs subjected to PCM. 3) The relationship between LVESP or LVWst and LVESD shipted downward and to the right after PCM, indicating reduced myocardial contractility. These findings suggest that the left ventricle in hypertrophied dog hearts subjected to PCM retains normal pump function, despite a low state in the myocardium.protein-calorie malnutrition ; sub-coronary aortic stenosis ; free acid ; 3-Methylhistidine ; myocardial contractility

Effects of protein-calorie restriction on mechanical function of hypertrophied cardiac muscle

“…Studies analyzing the effects of protein-calorie malnutrition (PCM) upon the mechanical performance of the hypertrophied cardiac muscles are scarce. The results showed that changes in the composition or in the amount of food ingested caused LV dysfunction [7][8][9] . Yokota et al 7 studied SHR receiving a low-protein diet (10% protein) for 2 and 4 weeks, and assessed the LV function by means of hemodynamic parameters, such as dT/dtmax/integrated isometric pressure and LV end diastolic pressure (LVEDP).…”

“…Yokota et al 7 studied SHR receiving a low-protein diet (10% protein) for 2 and 4 weeks, and assessed the LV function by means of hemodynamic parameters, such as dT/dtmax/integrated isometric pressure and LV end diastolic pressure (LVEDP). Tabayashi et al 8 analyzed dogs with aortic stenosis fed on a low protein-calorie diet for two weeks. The ventricular function was studied using the mean velocity of circumferential fiber shortening and using the relation between the parietal tension and the end-systolic diameter.…”

“…Information in the literature about the influence of different types of nutritional deficiencies on the functional behavior of the hypertrophied muscle is scarce [7][8][9] . Yokota et al 7 observed that SHR fed a protein-deficient diet showed deterioration of LV function.…”

“…Yokota et al 7 observed that SHR fed a protein-deficient diet showed deterioration of LV function. Tabayashi et al 8 observed that dogs with LV hypertrophy that underwent chronic PCM had normal pump function and a reduced myocardial contractility. Olivetti et al 9 , studying SHR with nutritional anemia, observed LV dilation and dysfunction in those animals.…”