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Updated: Feb 10, 2026

In vitro Assessment of Aortic Regurgitation Using Four-Dimensional Flow Magnetic Resonance Imaging
Published on: February 25, 2022
Impact of Heart Rate on Flow Measurements in Aortic Regurgitation
Mats Lidén1, Maciej Wodecki2, Per Thunberg3
1Department of Radiology, Faculty of Medicine and Health, Örebro University, Sweden. Electronic correspondence: matsliden@yahoo.com.
Background:
Flow measurements using cardiac magnetic resonance imaging (CMRI) enable quantification of the stroke volume, regurgitant volume (RV) and regurgitant fraction (RF) in patients with aortic regurgitation (AR). These variables are used to assess the severity of the valve disease and for the timing of surgery. The aim of the study was to investigate the impact of an increased heart rate on measurement of the RV and RF in patients with AR.
Methods:
Among 13 patients with known moderate or severe AR, regurgitant flow measurements, using phase-contrast cine magnetic resonance imaging, were obtained in the ascending aorta. Flow measurements were obtained at rest and at increased heart rates after intravenous administration of atropine.
Results:
The mean heart rate was 61 beats per min at rest and 91 beats per min after atropine administration. The RV and RF were 52 ml and 35% at rest, respectively, and 34 ml (p <0.001) and 30% (p = 0.065) at increased heart rate, respectively.
Conclusions:
An increased heart rate leads to a decreased RV. The RF is more stable and may therefore be preferable for severity grading in AR.
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