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[Phasic flow velocity characteristics of the right coronary artery in patients with aortic stenosis: a Doppler guide
Insights
Patients with aortic stenosis exhibit altered right coronary artery flow patterns, including significant systolic flow reversal, particularly in the distal portion. This finding correlates with the pressure gradient across the aortic valve.
Area of Science:
- Cardiovascular Physiology
- Medical Imaging and Diagnostics
Context:
- Aortic stenosis significantly impacts cardiac hemodynamics.
- Understanding coronary artery flow patterns is crucial for managing cardiovascular disease.
Purpose:
- To investigate the phasic flow velocity pattern of the right coronary artery in patients with aortic stenosis.
- To explore the relationship between coronary flow patterns and hemodynamic parameters in this patient group.
Summary:
- Doppler guidewire measurements in 10 aortic stenosis patients and 8 controls revealed distinct right coronary artery flow characteristics.
- Patients with aortic stenosis showed a higher diastolic to systolic peak velocity ratio and prevalent systolic flow reversal in the right coronary artery compared to controls.
- Distal systolic flow reversal velocity significantly correlated with the mean pressure gradient across the aortic valve.
Impact:
- Identifies characteristic alterations in right coronary artery flow dynamics in aortic stenosis.
- Suggests systolic flow reversal in the right coronary artery may serve as a marker for aortic stenosis severity.
- Provides insights into the interplay between valvular function and coronary hemodynamics.
Abstract:
This study investigated the characteristics of the phasic flow velocity pattern of the right coronary artery and the relationship to hemodynamic parameters in patients with aortic stenosis. Coronary flow velocities were recorded at the proximal (segment 1) and the distal (segment 4PD) portion of the right coronary artery using a Doppler guide wire (0.014-in, 15 MHz) in 10 patients with aortic stenosis and 8 control subjects with normal coronary arteries. The diastolic to systolic peak velocity ratio at both the proximal and distal portion were significantly greater in patients with aortic stenosis than in control subjects. Systolic flow reversal was not seen in the right coronary artery in control subjects, but it was observed in 5 patients (50%) at the proximal portion and in 10 patients (100%) at the distal portion. Peak velocity of flow reversal at the distal portion showed a significant correlation with mean pressure gradient across the aortic valve (y = -1.3x + 37.3, r = 0.71, p = 0.02). Systolic flow reversal is characteristic in the right coronary artery, especially at the distal portion, in patients with aortic stenosis. This may be related to the pressure difference across the aortic valve through the posterior descending artery.