DETERMINANTS OF PULMONARY ARTERY BLOOD VELOCITY PROFILE

肺动脉血流速度的决定因素

• 批准号: 3349234
• 负责人: Carol L Lucas
• 金额: $ 10.78万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-06-01 至 1989-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3349234
• 关键词: blood flow measurement; blood vessel disorder; cardiovascular disorder chemotherapy; diagnostic catheterization; disease /disorder model; hemodynamics; human subject; hydralazine; intraluminal angioplasty; mathematical model; model design /development; pulmonary artery; pulmonary hypertension; respiratory oxygen; ultrasound blood flow measurement; vascular resistance

Current methodologies for 1) quantifying pulmonary blood flow noninvasively with ultrasound and 2) estimating pulmonary input impedance with intraluminal velocity catheters rely heavily on the assumption that the velocity profile in the main pulmonary artery is flat. However, recent studies in humans and animals indicate that the mean profile along the long axis may be skewed toward the anterior wall. This skew has been attributed to flow reversals near the posterior wall during diastole and late systole which become accentuated and extend over a larger portion of the cross sectional area in the presence of pulmonary hypertension. Though attempts to correlate the magnitude and/or duration of flow reversal with pulmonary artery pressure have been made, little is known about 1) the source of the apparent backflow, 2) the effects of elevated flow on the velocity profile, or 3) discrepancies which may occur in impedance related parameters such as characteristic impedance and frequency of the first modulus minimum as a result of intraluminal catheter position. This study will address these issues by evaluating the relationships between velocity profiles and abnormal pulmonary hemodynamics in animal models using an intraluminal 20 MHz pulsed Doppler device. Profiles will be obtained along the long and short axes to create a two-dimensional profile which will be correlated with electromagnetically measured blood flow. Studies performed on the main pulmonary artery will be duplicated on the right pulmonary artery to determine the extent of the flow reversal phenomena as well as the feasibility of using the input impedance of the right rather than the main pulmonary artery to assess pulmonary vascular impairment. Chronic pulmonary hypertension and/or elevated pulmonary blood flow will be created in dogs and lambs. Once control profiles are obtained, the effects of 100% oxygen inhalation and hydralazine will be evaluated. Efforts will be made to improve current methods of measurement by reducing intraluminal probe size and time needed to complete a profile. Findings in the animal models will be compared to patient data. The spectra in the main pulmonary artery, currently being obtained intraoperatively using electromagnetic flow probes, will be compared to the spectra obtained by measuring velocity in the main and right pulmonary artery with a hand-held extraluminal pulsed Doppler probe. Finally, efforts will be made to obtain spectra in the right pulmonary artery whenever studies of the effects of oxygen inhalation are done in the catheterization laboratory to assess vascular tone in patients with abnormal pulmonary hemodynamics.

用于1）非侵入性地量化肺血流的当前方法 和2）估计肺输入阻抗， 腔内速度导管在很大程度上依赖于假设， 主肺动脉的流速曲线是平坦的。 但最近的 在人类和动物中的研究表明，沿着长链沿着的平均轮廓 轴可以朝向前壁偏斜。 这种倾斜被归因于 在舒张末期和收缩晚期， 其变得突出并在十字架的较大部分上延伸 肺动脉高压时的截面积。 虽然尝试 为了将血流反向的幅度和/或持续时间与肺动脉血流的速度和/或流速相关， 动脉压已经取得，很少有人知道1）的来源， 表观回流，2）上升流对流速剖面的影响， 或3）阻抗相关参数中可能出现的差异， 第一模量最小值的特性阻抗和频率作为 管腔内导管位置的结果。 这项研究将解决这些问题 通过评估速度剖面和 在使用管腔内20 MHz脉冲多普勒装置。 将沿沿着获取剖面图， 短轴以创建将被关联的二维轮廓 通过电磁测量血流。 对下列药物进行的研究 将在右肺动脉上复制主肺动脉， 确定逆流现象的程度以及 使用右输入阻抗而不是主输入阻抗的可行性 肺动脉以评估肺血管损伤。 慢性 将产生肺动脉高压和/或升高的肺血流量 在狗和羊身上。 一旦获得控制曲线，100% 将评估氧气吸入和肼苯哒嗪。 将努力 通过减少管腔内探针来改进当前的测量方法 完成配置文件所需的大小和时间。 动物模型中的发现 将与患者数据进行比较。 主肺动脉频谱 动脉，目前正在术中使用电磁 流量探头，将比较，通过测量速度获得的频谱 在主肺动脉和右肺动脉中用手持式腔外脉冲 多普勒探测器。 最后，将努力获得光谱， 右肺动脉每当研究吸氧的影响 在导管室进行，以评估血管张力， 肺血流动力学异常的患者。