Noninvasive echocardiographic measurement of pulmonary acceleration time to ejection time ratio strongly correlated with invasive right ventricular systolic pressure in mice (r2=-0.76, P<0.0001).
Does echocardiography accurately estimate right ventricular systolic pressure compared to right heart catheterization in murine models of pulmonary hypertension?
Echocardiography-derived pulmonary acceleration time and ejection time provide a reliable, noninvasive method to estimate right ventricular systolic pressure in murine models of pulmonary hypertension.
Effect estimate: r2=-0.76
p-value: p=<0.0001
BACKGROUND: Genetically modified mice offer the unique opportunity to gain insight into the pathophysiology of pulmonary arterial hypertension. In mice, right heart catheterization is the only available technique to measure right ventricular systolic pressure (RVSP). However, it is a terminal procedure and does not allow for serial measurements. Our objective was to validate a noninvasive technique to assess RVSP in mice. METHODS AND RESULTS: Right ventricle catheterization and echocardiography (30-MHz transducer) were simultaneously performed in mice with pulmonary hypertension induced acutely by infusion of a thromboxane analogue, U-46619, or chronically by lung-specific overexpression of interleukin-6. Pulmonary acceleration time (PAT) and ejection time (ET) were measured in the parasternal short-axis view by pulsed-wave Doppler of pulmonary artery flow. Infusion of U-46619 acutely increased RVSP, shortened PAT, and decreased PAT/ET. The pulmonary flow pattern changed from symmetrical at baseline to asymmetrical at higher RVSPs. In wild-type and interleukin-6-overexpressing mice, the PAT correlated linearly with RVSP (r(2)=-0.67, P32 mm Hg) were 100% (7/7) and 86% (6/7), respectively, for both indices (cutoff values: PAT, <21 ms; PAT/ET, <39%). Intraobserver and interobserver variability of PAT and PAT/ET were <6%. CONCLUSIONS: Right ventricular systolic pressure can be estimated noninvasively in mice. Echocardiography is able to detect acute and chronic increases in RVSP with high sensitivity and specificity as well as to assess the effects of treatment on RVSP. This noninvasive technique may permit the characterization of the evolution of pulmonary arterial hypertension in genetically modified mice.
Thibault et al. (Fri,) conducted a other in Pulmonary arterial hypertension (murine model). Echocardiography (pulmonary acceleration time and ejection time) vs. Right heart catheterization (invasive RVSP) was evaluated on Correlation of pulmonary acceleration time to ejection time ratio (PAT/ET) with right ventricular systolic pressure (r2=-0.76, p=<0.0001). Noninvasive echocardiographic measurement of pulmonary acceleration time to ejection time ratio strongly correlated with invasive right ventricular systolic pressure in mice (r2=-0.76, P<0.0001).