Difference between proximal and distal right coronary flow velocity pattern in humans.

The purpose of this study is to clarify the difference between proximal and distal right coronary artery flow velocity pattern in humans. Each portion of the coronary artery in thirteen patients with chest pain syndrome was measured by means of Doppler guide wire. The systolic/diastolic peak velocity ratio and velocity integral ratio at the proximal portion of the right coronary artery were significantly higher than those at distal portion of the right coronary artery (0.97 +/- 0.27, 0.61 +/- 0.20, 0.66 +/- 0.19, 0.44 +/- 0.13, respectively). In the right ventricular branch, coronary flow velocity pattern showed systolic dominancy. Systolic/diastolic peak velocity ratio and integral ratio showed 1.69 +/- 0.62 and 1.00 +/- 0.62 in the right ventricular branch, respectively. It is speculated that the less marked diastolic predominant pattern in the proximal right coronary artery flow velocity may be due to the fact that the proximal right coronary artery supplies both the right and left ventricle but that the distal right coronary artery supplies only the left ventricular inferior wall.