斎藤 勇三, 鶴田 育男, 向山 茂雄, 前田 達朗, 田村 康二

Yuzo SAITO, Ikuo TSURUTA, Shigeo MUKAIYAMA, Tatsuro MAEDA, Kohji TAMURA

山梨医科大学第二内科

The Second Department of Internal Medicine, Yamanashi Medical College

キーワード : Superior vena cava flow, Doppler echocardiography

We examined superior vena cava (SVC) flow velocity patterns in 23 healthy subjects by pulsed Doppler echocardiography. SVC flow was recorded with a transducer in the right supraclavicular fossa, approximating a 0° Doppler angle. The Doppler sample volume could be positioned 2 cm, 4 cm, 5 cm, 6 cm, and 7 cm downstream from the junction of the brachiocephalic veins.
No difference in SVC flow was found between positions 2 cm and 4 cm downstream from the junction of the brachiocephalic veins. In contrast, 5 cm or more downstream the peak velocities of large antegrade flow during ventricular systole (S wave) and during diastole (D wave) increased significantly, and the peak velocity of the D to S wave ratio (D/S) decreased with distance from the junction of the brachiocephalic veins. The starting points and the peaks of S and D waves tended to occur earlier with increasing distance from the junction of the brachiocephalic veins.
These findings demonstrate variations in the SVC flow velocity pattern, and indicate that SVC flow should be recorded 4 cm or less downstream of the junction of the brachiocephalic veins.