The relation between transaortic pressure difference and flow during dobutamine stress echocardiography in patients with aortic stenosis. Issue 1 (1st July 1999)

• Record Type: Journal Article
• Authors: Takeda, S; Rimington, H; Chambers, J
• Is Part Of: Heart. Volume 82:Issue 1(1999)
• Page Start: 11
• Page End: 14
• Publication Date: 1999-07-01
• Subjects: aortic stenosis -- continuity equation -- resistance -- Doppler echocardiography; Heart -- Diseases -- Treatment -- Periodicals; Cardiology -- Periodicals; 616.12
• DOI: 10.1136/hrt.82.1.11
• Languages: English
• ISSNs: 1355-6037

Abstract

Abstract : OBJECTIVE: To investigate the relation between transaortic pressure difference and flow in patients with aortic stenosis. METHODS: 50 asymptomatic patients with all grades of aortic stenosis were studied using dobutamine stress echocardiography. Individual plots of mean pressure drop against flow were drawn. Comparisons were made between grades of aortic stenosis as defined by the continuity equation. RESULTS: A significant linear relation between pressure difference and flow was found in 34 patients (68%). There was a significant curvilinear relation in four (8%), while no significant regression line could be fitted in 12 (24%). In the 34 patients with linear fits, the slopes (mean (SD)) were 0.08 (0.07) in mild, 0.10 (0.04) in moderate, and 0.22 (0.16) in severe aortic stenosis (p = 0.0055). CONCLUSIONS: Transaortic pressure difference can be related directly to flow in many patients with all grades of aortic stenosis. However, there are individual differences in slope and intercept suggesting that resistance calculated at rest may not always be representative. Raw pressure drop/flow plots may be an alternative method of describing valve function.