Impact of Blood Pressure on the Doppler Echocardiographic Assessment of Aortic Stenosis Severity

Stephen H Little ¹, Kwan L Chan ² and Ian G Burwash ^2*

¹ University of Western Ontario, Canada
² University of Ottawa Heart Institute, Canada

^* To whom correspondence should be addressed. E-mail: iburwash{at}ottawaheart.ca.

Accepted 19 September 2006

Abstract

Objectives To investigate the impact of blood pressure (BP) on the Doppler echocardiographic (Doppler-echo) evaluation of aortic stenosis (AS) severity.

Methods Handgrip exercise or phenylephrine infusion was used to increase BP in 22 patients with AS. Indices of AS severity [mean pressure gradient (ÄPmean), aortic valve area (AVA), valve resistance, percent 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 BP increased (99±8 vs. 121±10mmHg, p<0.0001), systemic vascular resistance (SVR) increased (1294±264 vs. 1552±372dynescm-5, p=0.0005) and mean transvalvular flow rate (Qmean) decreased (323±67 vs. 306±66ml/s, p=0.02). There was no change in ÄPmean (36±13 vs. 36±14mmHg, p=NS). However, there was a decrease in AVA (1.15±0.32 vs. 1.09±0.33cm2, p=0.02) and ELCo (1.32±0.40 vs. 1.24±0.42cm2, p=0.04), and an increase in valve resistance (153±63 vs. 164±74dynescm-5, p=0.02), suggesting a more severe valve stenosis. In contrast, %LVSW loss decreased (19.8±6 vs. 16.5±6%, p<0.0001) 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<0.0001).

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 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.

Keywords: Doppler echocardiography, aortic stenosis, hypertension, valve area, valve resistance

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

Relevant Articles

WEB TOP 10
Heart 2007 93: 1023. [Extract] [Full Text] [PDF]

This article has been cited by other articles:

• Dumesnil, J. G., Pibarot, P., Carabello, B. (2009). Paradoxical low flow and/or low gradient severe aortic stenosis despite preserved left ventricular ejection fraction: implications for diagnosis and treatment. Eur Heart J 0: ehp361v1-ehp361 [Abstract] [Full Text]  
• Ennezat, P V, Marechaux, S, Iung, B, Chauvel, C, LeJemtel, T H, Pibarot, P (2009). Exercise testing and exercise stress echocardiography in asymptomatic aortic valve stenosis. Heart 95: 877-884 [Abstract] [Full Text]  
• Rahimtoola, S. H. (2009). The Year in Valvular Heart Disease. J Am Coll Cardiol 53: 1894-1908 [Full Text]  
• Baumgartner, H., Hung, J., Bermejo, J., Chambers, J. B., Evangelista, A., Griffin, B. P., Iung, B., Otto, C. M., Pellikka, P. A., Quinones, M. (2009). Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice. Eur J Echocardiogr 10: 1-25 [Full Text]  
• Mascherbauer, J., Fuchs, C., Stoiber, M., Schima, H., Pernicka, E., Maurer, G., Baumgartner, H. (2008). Systemic pressure does not directly affect pressure gradient and valve area estimates in aortic stenosis in vitro. Eur Heart J 29: 2049-2057 [Abstract] [Full Text]  
• Kaden, J. J., Haghi, D. (2008). Hypertension in aortic valve stenosis--a Trojan horse. Eur Heart J 29: 1934-1935 [Full Text]  
• Linhartova, K. (2008). Impact of blood pressure on the Doppler echocardiographic assessment of severity of aortic stenosis. Heart 94: 508-508 [Full Text]  
• Burwash, I G, Little, S H, Chan, K L (2008). The authors' reply. Heart 94: 508-508 [Full Text]  
• Pibarot, P., Dumesnil, J. G (2007). Assessment of aortic stenosis severity: check the valve but don't forget the arteries!. Heart 93: 780-782 [Full Text]