RT Journal Article
SR Electronic
T1 Impact of blood pressure on the Doppler echocardiographic assessment of severity of aortic stenosis
JF Heart
JO Heart
FD BMJ Publishing Group Ltd and British Cardiovascular Society
SP 848
OP 855
DO 10.1136/hrt.2006.098392
VO 93
IS 7
A1 Stephen H Little
A1 Kwan-Leung Chan
A1 Ian G Burwash
YR 2007
UL http://heart.bmj.com/content/93/7/848.abstract
AB Objective: To investigate the impact of blood pressure (BP) on the Doppler echocardiographic (Doppler-echo) evaluation of severity of aortic stenosis (AS). Methods: Handgrip exercise or phenylephrine infusion was used to increase BP in 22 patients with AS. Indices of AS severity (mean pressure gradient (ΔPmean), aortic valve area (AVA), valve resistance, percentage left ventricular stroke work loss (% LVSW loss) and the energy loss coefficient (ELCo)) were measured at baseline, peak BP intervention and recovery. Results: From baseline to peak intervention, mean (SD) BP increased (99 (8) vs 121 (10) mm Hg, p<0.001), systemic vascular resistance (SVR) increased (1294 (264) vs 1552 (372) dyne×s/cm5, p<0.001) and mean (SD) transvalvular flow rate (Qmean) decreased (323 (67) vs 306 (66) ml/s, p = 0.02). There was no change in ΔPmean (36 (13) vs 36 (14) mm Hg, p = NS). However, there was a decrease in AVA (1.15 (0.32) vs 1.09 (0.33) cm2, p = 0.02) and ELCo (1.32 (0.40) vs 1.24 (0.42) cm2, p = 0.04), and an increase in valve resistance (153 (63) vs 164 (74) dyne×s/cm5, p = 0.02), suggesting a more severe valve stenosis. In contrast, % LVSW loss decreased (19.8 (6) vs 16.5 (6)%, p<0.001), suggesting a less severe valve stenosis. There was an inverse relationship between the change in mean BP and AVA (r =  –0.34, p = 0.02); however, only the change in Qmean was an independent predictor of the change in AVA (r = 0.81, p<0.001). Conclusions: Acute BP elevation due to increased SVR can affect the Doppler-echo evaluation of AS severity. However, the impact of BP on the assessment of AS severity depends primarily on the associated change in Qmean, rather than on an independent effect of SVR or arterial compliance, and can result in a valve appearing either more or less stenotic depending on the direction and magnitude of the change in Qmean.