Echocardiographic parameters discriminating myocardial infarction with pulmonary congestion from myocardial infarction without congestion in the mouse

Abstract

Our aim was to establish parameters describing systolic and diastolic function in mice after myocardial infarction (MI) that distinguish MI with pulmonary congestion from MI without congestion. Echocardiography, left ventricular (LV) catheterization, and infarct size measurements were performed on days 3, 5, 7, and 14 after ligation of the left coronary artery in C57BL/6 mice. Sham-operated mice were used as controls (Sham). MI mice with lung weight normalized to tibial length >125% of the average in the corresponding Sham group were considered to have pulmonary congestion (MIchf). MI mice with a smaller increase were called MI nonfailing (MInf). An infarct >40% of total LV circumference measured in two-dimensional long axis distinguished MIchf from MInf on both an average and an individual basis. Mean maximum rate of rise of LV pressure, LV fractional shortening, and posterior wall shortening velocity were significantly lower in MIchf compared with Sham at all time points and to MInf at 7 days. The diastolic parameters mitral flow deceleration velocity, LV end-diastolic pressure, and maximum rate of decline in LV pressure (LVdP/dtmin) discriminated the MIchf groups from Sham at all time points. Mitral flow deceleration velocity and LVdP/dtmin separated MIchf from MInf at 7 days. In addition to distinguishing all the groups on an average basis, left atrial diameter distinguished all MIchf animals from Sham and MInf. In conclusion, significantly increased left atrial diameter and infarct size >40% of total LV circumference may serve as major criteria for heart failure with pulmonary congestion after MI in mice.