Regional assessment of in vivo myocardial stiffness using 3D magnetic resonance elastography in a porcine model of myocardial infarction.

Purpose: The stiffness of a myocardial infarct affects the left ventricular pump function and remodeling. Magnetic resonance elastography (MRE) is a noninvasive imaging technique for measuring soft-tissue stiffness in vivo. The purpose of this study was to investigate the feasibility of assessing in vivo regional myocardial stiffness with high-frequency 3D cardiac MRE in a porcine model of myocardial infarction, and compare the results with ex vivo uniaxial tensile testing.

Cardiotropin-1 and myocardial strain change heterogeneously in cardiomyopathy.

Background: The pacing model of heart failure produces heterogeneous changes in wall stress and myocyte diameter. The purpose of this study was to measure regional changes in cardiotrophin-1 (CT-1), a cytokine thought to play a role in LV remodeling, and regional changes in LV strain as measured with magnetic resonance imaging.

Materials And Methods: Dilated cardiomyopathy was induced in nine mongrel dogs over 4 wk by rapid pacing using a right ventricular epicardial lead.