title: Assessment of hemodynamic effects of angiotensin-converting enzyme inhibitor therapy in chronic aortic regurgitation by using velocity-encoded cine magnetic resonance imaging.
abstract: Long-term treatment with angiotensin-converting enzyme (ACE) inhibitors has beneficial effects in patients with chronic aortic regurgitation by reducing left ventricular volumes and regurgitant fraction. Velocity-encoded cine magnetic resonance imaging can directly measure antegrade (forward stroke volume) and retrograde blood flow (regurgitant volume) in the ascending aorta. Velocity-encoded cine magnetic resonance imaging was used in 9 patients with moderate to severe aortic regurgitation (regurgitant fraction 49% +/- 17%) to measure regurgitant fraction, regurgitant volume, and forward stroke volume at baseline and 3 months after therapy with enalapril (mean dose 29 +/- 13 mg). Ten additional patients with aortic regurgitation without any drug therapy served as a control group. In the treatment group, systolic blood pressure slightly decreased from 132 +/- 20 mm Hg to 121 +/- 14 mm Hg (p = not significant), whereas diastolic blood pressure and heart rate (beats per minute) remained unchanged. Regurgitant fraction decreased in 6 patients (responders) from 49% +/- 19% to 39% +/- 20% (percentage change 24% +/- 14%, p = 0.002) and was unchanged in 3 patients (nonresponder, 49% +/- 19% vs 51% +/- 16%; p = not significant). In the responder group, forward stroke volume increased from 128 +/- 32 ml to 148 +/- 57 ml, whereas regurgitant volume remained unchanged (67 +/- 40 ml vs 65 +/- 51 ml). At baseline, the responder group had a significant higher total vascular resistance than the nonresponder group (998 +/- 538 dyne.sec.cm-5 vs 625 +/- 214 dyne.sec.cm-5; p < 0.05). With enalapril treatment, total vascular resistance in the responder group tended to decrease (891 +/- 576 dyne.sec.cm-5), but slightly increased in the nonresponder group (679 +/- 276 dyne.sec.cm-5). The control group showed no changes in regurgitant fraction, regurgitant volume, forward stroke volume, and total vascular resistance at follow-up.
authors.affiliation: Department of Radiology, University of California, San Francisco, USA.
authors.forename: S
authors.initials: S
authors.lastname: Globits
authors.forename: L
authors.initials: L
authors.lastname: Blake
authors.forename: M
authors.initials: M
authors.lastname: Bourne
authors.forename: N
authors.initials: N
authors.lastname: Fujita
authors.forename: A
authors.initials: A
authors.lastname: Duerinckx
authors.forename: D
authors.initials: D
authors.lastname: Szolar
authors.forename: M
authors.initials: M
authors.lastname: Cheitlin
authors.forename: C B
authors.initials: CB
authors.lastname: Higgins
mesh_terms: D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D001011:Aorta / Q000473:pathology; D001022:Aortic Valve Insufficiency / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D004656:Enalapril / Q000627:therapeutic use*; D005240:Feasibility Studies; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D004656:Enalapril