Figure 2. Hemodynamic evidence for aortic valvular stenosis in Klf3^H275R/+ mice.

Adult Klf3^H275R/+ mice with high aortic blood velocities and their cage-mate controls were studied. (A) Doppler ultrasound was used to measure transvalvular blood velocity in Klf3^H275R/+ mutants (dark bars) relative to WT (light bars). Blood velocity in the left ventricular outflow tract (LVOT) was similar in mutants and WT but became elevated at the level of the aortic valve and remained elevated in the proximal ascending aorta (24–33 wk adult mice, n = 5 per group, mean ± SE). (B) The transvalvular pressure gradient was measured by pulling a catheter from the left ventricle (LV) to the aorta. The gradient in systolic blood pressure from the LV to the aorta was greater in Klf3^H275R/+ mutant (right) than WT mice (left). (C) Left ventricular systolic blood pressures (LV-SBP) were similar but aortic systolic (Ao-SBP) and aortic diastolic (Ao-DBP) blood pressures were lower in Klf3^H275R/+ mutants (dark bars on right) than WT mice (light bars on left). The LV-SBP to Ao-SBP gradient (mean ± SE above bars) was significantly greater in mutants suggesting aortic stenosis (18–25 wk adult mice, n = 10 WT, n = 9 mutants, mean ± SE). *** P<0.001 Klf3^H275R/+ vs. WT.