Left ventricular contractility is impaired following myocardial infarction in the pig and rat: assessment by the end systolic pressure-volume relation using a single-beat estimation technique and cine magnetic resonance imaging

• Published in: Annals of biomedical engineering Vol. 28; no. 5; pp. 484 - 494
• Main Authors: Setser, R, Henson, 2nd, R E, Allen, J S, Fischer, S E, Wickline, S A, Loren, C H
• Format: Journal Article
• Language: English
• Published: United States Springer Nature B.V 01.05.2000
• Subjects: Animal species; Animals; Assessments; Biomedical Engineering; Elasticity; Heart; Heart attacks; Human; Humans; Infarction; Magnetic resonance imaging; Magnetic Resonance Imaging, Cine; Male; Myocardial infarction; Myocardial Infarction - complications; Myocardial Infarction - physiopathology; Rats; Rats, Sprague-Dawley; Reproduction; Species Specificity; Stroke Volume; Swine; Ventricular Dysfunction, Left - etiology; Ventricular Dysfunction, Left - physiopathology
• ISSN: 0090-6964; 1573-9686
• DOI: 10.1114/1.289

The end systolic pressure-volume relation (ESPVR) has been shown to be a relatively load independent measure of left ventricular (LV) contractility. Recently, several single-beat ESPVR computation methods have been developed, enabling the quantification of LV contractility without the need to alter vascular loading conditions on the heart. Using a single-beat ESPVR method, which has been validated previously in humans and assumes that normalized elastance is constant between individuals of a species, we studied the effects of myocardial infarction on LV contractility in two species, the rat and the pig. In our studies, LV pressure was acquired invasively and LV volume determined noninvasively with magnetic resonance imaging, at one week postinfarction in pigs and at 12 weeks postinfarction in rats. Normalized systolic elastance curves in both animal species were not statistically different from that of humans. Also, the slope of the ESPVR (Ees) decreased significantly following infarction in both species, while the volume-axis intercept (V0) was unaffected. These results indicate that a single-beat ESPVR method can be used to measure the inotropic response of the heart to myocardial infarction, and that the basis for this method (i.e., constant normalized elastance) is applicable to a variety of mammalian species.