Cross sectional profiles of systolic flow velocities in left ventricular outflow tract of normal subjects.
Cross sectional profiles of systolic flow velocities in left ventricular outflow tract of normal subjects.
复制标题
正常受试者左心室流出道收缩期血流速度的横截面轮廓。
DOI：
10.1136/hrt.74.1.34
复制
发表时间：
1995
影响因子：
--
通讯作者：
V. Poutanen
中科院分区：
文献类型：
--
作者：
Markku Kupari;P. Hekali;V. Poutanen
背景--血液以平坦的速度流经左心室流出道的想法最近受到了质疑。目的：应用磁共振成像技术建立正常受试者主动脉下全横断面血流速度图。研究对象--9名年龄在25岁至56岁之间的非心脏病患者。设计--心脏门控电影磁共振成像采用1.0T垂直于收缩中期主动脉环下方0.5-1.0 cm左室流出道纵轴的磁铁。在整个收缩期沿垂直于图像平面的血流方向每隔30-40ms编码一次速度。主要观察指标--在主动脉下血流区域的9个不同区域(每个环的面积为0.2 cm2)重建的收缩速度-时间曲线。以收缩期峰速度和平均流速作为局部血流的指标。结果峰值流速的空间不均一性平均为18.2%(5.0%)，平均流速不均一性为19.2%(3.5%)。在各区域测量中，主动脉下血流区域的最高峰值流速和平均收缩流速有显著的趋势(P<；0.05)。血流中心区峰值流速平均为98(8)cm/S，空间平均为94(5)cm(P=0.013)。结论--左心室流出道的收缩速度分布偏向于流出区前内侧部分的最快血流。在流区中心测得的峰值速度略微高估了一致的空间平均速度。
BACKGROUND--The idea that blood passes through the left ventricular outflow tract with a flat velocity profile has recently been questioned. OBJECTIVE--To construct flow velocity profiles by magnetic resonance imaging over the whole cross sectional subaortic flow area in normal subjects. SUBJECTS--Nine people without heart disease aged 25 to 56. DESIGN--Cardiac gated cine magnetic resonance images were produced with a 1.0 T magnet perpendicular to the longitudinal axis of the left ventricular outflow tract 0.5 to 1.0 cm below the aortic annulus in mid-systole. Velocity was encoded every 30-40 ms throughout systole in the direction of flow perpendicular to the image plane. MAIN OUTCOME MEASURES--Systolic velocity-time curves reconstructed in nine different regions (area of each circle 0.2 cm2) of the subaortic flow area. The systolic peak velocity and the mean flow rate were taken as indices of regional flow. RESULTS--The spatial inhomogeneity of the peak velocity, calculated as the percentage ratio of the range of the regional measurements to their mean, averaged 18.2% (5.0%), and the inhomogeneity of the mean flow rate was 19.2% (3.5%). There were significant trends (P < 0.05) across the regional measurements towards highest peak velocities and mean systolic flow rate in the anteromedial sector of the subaortic flow area. The peak systolic velocity in the centre of the flow area averaged 98 (8) cm/s while the coincident spatial average was 94 (5) cm (P = 0.013). CONCLUSIONS--The distribution of systolic velocities across the left ventricular outflow tract is skewed towards fastest flow in the anteromedial sector of the flow area. The peak velocities measured in the centre of the flow area slightly overestimate the coincident spatial average velocities.
影响因子：
37.8
作者：
LEWIS, JF;KUO, LC;QUINONES, MA
通讯作者：
QUINONES, MA