Noninvasive Assessment of Murine Pulmonary Arterial Pressure

Abstract

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

The Sugen 5416/Hypoxia Mouse Model of Pulmonary Hypertension Revisited: Long‐Term Follow‐Up

“…It is also possible that PAAT does not have enough sensitivity to distinguish between RV pressures of 34 and 45 mmHg. 32 In contrast to our study, Ciuclan et al 6 did find a significantly lower PAAT in SuHx mice after 3 weeks of hypoxia compared with VehHx mice, but the VehHx mice in that study had a normal PAAT after 3 weeks of hypoxia despite having an elevated RVSP of 35 mmHg, which is not consistent with the literature 32 and our results.…”

“…PAAT increased over the 10-week normoxic recovery in both groups, and although SuHx mice had lower PAAT than VeHx mice after 10 weeks of recovery, this difference was not significant. PAAT is known to become shorter with higher RV and PA pressure in both humans and animals, [24][25][26][27][28][29][30][31][32] and it is a useful marker of PH in small animals that do not reliably develop quantifiable tricuspid regurgitation. PAAT has been hypothesized to be shorter in PH because of the reduced compliance and increased impedance of the pulmonary arterial system, 33 and it may provide additional information about these important parameters (compliance and impedance) when compared with invasively measured RV pressure.…”

Effects of Transplanted Human Cord Blood-Mononuclear Cells on Pulmonary Hypertension in Immunodeficient Mice and Their Distribution

“…By analyzing the waveform, the following variables were measured : pulmonary acceleration time (AT) and right ventricular ejection time (ET). As an index of PAH, we calculated AT/ET as previously described (14).…”

Assessment of Right Ventricular Structure and Function in Mouse Model of Pulmonary Artery Constriction by Transthoracic Echocardiography

“…Inter-observer and intra-observer variability are low for diameter measurements using this mode, but wall thickness measurements tend to be quite variable 7 . Pulsed Doppler with color (PW or Color Doppler) has been used to evaluate valvular regurgitation 8,9 . Similar to LV, the RV plays an important role and is a significant predictor of morbidity and mortality in patients afflicted with cardiopulmonary disease 1,7,10 .…”

“…Similar to LV, the RV plays an important role and is a significant predictor of morbidity and mortality in patients afflicted with cardiopulmonary disease 1,7,10 . However, echocardiographic evaluation of RV is inherently challenging due to its complex shape 5,11 and its retrosternal position that blocks the ultrasound waves 8,9 . RV is a crescent shaped structure wrapping around the LV and has a complex anatomy with thin walls that are accustomed to low pressure and resistance to pulmonary vasculature 6 .…”