Kashiwagi Y, Beppu S, Ishikura F, Ueda H, Yagura S, Kayano H
School of Allied Health Sciences, Osaka University, Faculty of Medicine, Yamadaoka 1-7, Suita, Osaka 565-0871.
J Cardiol. 2001 Jun;37(6):335-40.
Levovist can opacify the myocardium via venous injection, and is widely used in the clinical field. However, left ventricular opacification deteriorates during oxygen inhalation using Albunex, one of the first generation of contrast agents. This study examines the effect of blood oxygen pressure on the myocardial opacification by Levovist.
Myocardial contrast echocardiography (Toshiba Power Vision 6000) was performed using second harmonic imaging, intermittent exposure of ultrasound (every 4 cardiac beats) and acoustic power of 1.4 mechanical index. The video intensity of the ventricular septum after venous injection of Levovist (0.5 ml of 300 mg/ml) was measured under various respiratory conditions by manipulating the respirator and oxygen inhalation. Arterial blood gas was measured and correlated with the myocardial video intensity.
The video intensity of myocardial opacification was lower with higher oxygen pressure in the arterial blood. Visual recognition of myocardial opacification was only 14% under high oxygen pressure over 200 mmHg. Microbubbles of Levovist form from normal air, and are easily affected by the gas concentration of the surrounding blood.
Myocardial opacification using Levovist is deteriorated under high oxygen pressure at examination.
Levovist（声诺维）可通过静脉注射使心肌显影，在临床领域广泛应用。然而，使用第一代造影剂之一的Albunex进行吸氧时，左心室显影会变差。本研究旨在探讨血氧压力对Levovist心肌显影的影响。
采用二次谐波成像、超声间歇发射（每4个心动周期）及1.4机械指数的声功率，使用心肌对比超声心动图（东芝Power Vision 6000）。通过操作呼吸机和吸氧，在不同呼吸条件下测量静脉注射Levovist（0.5 ml，300 mg/ml）后室间隔的视频强度。测量动脉血气并与心肌视频强度相关联。
动脉血氧压力越高，心肌显影的视频强度越低。在高于200 mmHg的高氧压力下，心肌显影的视觉识别率仅为14%。Levovist的微泡由普通空气形成，容易受到周围血液气体浓度的影响。
在检查时，高氧压力下使用Levovist进行心肌显影会变差。
