Duplex Sonography of the Carotid Arteries in Patients with Pure Aortic Regurgitation: Pulse Waveform and Hemodynamic Changes and a New Indicator of the Severity of Aortic Regurgitation

Purpose: To determine the changes of multiple hemodynamic parameters and pulse wave contour in pure aortic regurgitation (AR) and to present a new indicator of the severity of AR (shrink ratio of proximal common carotid artery). Material and Methods: The sonograms of 42 patients (31 M, 11 F; 16-68 years) with pure AR and 18 control subjects (15 M, 3 F; 20-47 years) were assessed for velocities and indices, and change of pulse wave contour (bisferious pattern, zero level and retrograde diastolic flow) in each carotid artery. Shrink ratio (maximum diameter-minimum diameter maximum diameter) of each proximal common carotid artery was calculated. Results: Bisferious waveforms seen in patients with AR grade 1, grade 2, and grade 3-4 were 66%, 83%, and 88%, respectively. Diastolic reversed flow was determined in 7 (39%) of 18 patients with AR grade 3-4. Three patients (25%) with AR grade 2 and 4 patients (22%) with AR grade 3-4 had zero level diastolic flow in the common carotid artery. Statistically significant changes of decreased end-diastolic velocity, increased peak systolic velocity end-diastolic velocity, resistivity index, and pulsatility index were revealed, especially in AR grade 3-4 compared to controls. Significantly increased shrink ratio was seen only in AR grade 3-4. Conclusion: Increased shrink ratio or changes in hemodynamics or pulse waveform can be used in recognition of AR.