Effects of changes in chamber geometry by chronic pressure-overload on wall stress and strain as studied in the potassium-arrested canine left ventricle.
We studied differences in stress and strain distributions within the left ventricular wall between the normal heart and the pressure-overload hypertrophied heart. Diastolic left ventricular pressure-volume (P-V) relations of both ventricles were recorded using isolated potassium-arrested heart preparations. The P-V relations thus obtained were analyzed based on the large deformation theory. In this study, the left ventricle was assumed to be a thick spherical shell and its wall was assumed to consist of a homogeneous elastic material. In the hypertrophied heart, the wall stress at every layer of the diastolic left ventricle was smaller than that of the normal heart except in the close vicinity of the endocardial surface when compared at the same left ventricular pressure. Therefore, we concluded that the occurrence of concentric hypertrophy under pressure-overload may contribute in reducing the preload of the hypertrophied ventricle. It was thus suggested that the preload reserve of the pressure-overload heart exceeded that of the normal heart.
D000818:Animals; D006332:Cardiomegaly / Q000473:pathology / Q000503:physiopathology*; D003971:Diastole; D004285:Dogs; D006321:Heart / Q000503:physiopathology*; D006352:Heart Ventricles; D008433:Mathematics; D009200:Myocardial Contraction; D009206:Myocardium / Q000473:pathology; D011188:Potassium / Q000494:pharmacology; D011312:Pressure; D013318:Stroke Volume
D011188:Potassium