Flow during exercise in the total cavopulmonary connection measured by magnetic resonance velocity mapping
Flow during exercise in the total cavopulmonary connection measured by magnetic resonance velocity mapping
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DOI：
10.1136/heart.87.6.554
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发表时间：
2002-06-01
期刊：
影响因子：
5.7
通讯作者：
Hjortdal, VE
中科院分区：
文献类型：
--
作者：
Pedersen, EM;Stenbog, EV;Hjortdal, VE
目的：测量全腔静脉连接（TCPC）患者在静息时和运动后即刻的腔静脉和肺血流。设计：一项观察性研究，使用患者作为自身对照。使用磁共振（MR）相位对比技术和MR兼容自行车测力计的组合，测量上级腔静脉、下腔静脉隧道以及在休息和运动时的左右肺动脉中（0.5 W/kg和1.0 W/kg）。患者：11名年龄为11.4岁的患者（4.6）年（平均值（SD））研究6.3 TCPC手术后3.8年。主要观察指标：静息和运动时测量TCPC连接的所有四个分支的血流量。结果：体静脉回流（下腔静脉加上级腔静脉）从2.5（0.1）l/min/m2（平均值（SEM））增加到运动期间的4.4（0.4）l/min/m2（p < 0.05），均匀分布于两个肺动脉。静息时下腔静脉血流量高于上级静脉血流量，为1.4（0.1）v 1.1（0.1）1/min/m（2）（p < 0.05），运动时下腔静脉血流量增加一倍上级腔静脉血流量仅轻微增加（至1.4（0.1）l/min/m2）（P < 0.05）。下腔静脉与上级腔静脉血流量之比为1.4（0.1）休息时，增加至1.8（0.1分）（p < 0.05），0.5 W/kg，2.2 W/kg结论：运动后立即使用MR技术可以进行定量血流测量。仰卧腿运动导致下腔静脉血流量增加两倍以上。这是均匀分布到两个肺，表明肺阻力，而不是几何形状决定流量分布在TCPC循环。
Objective: To measure coval and pulmonary flows at rest and immediately after exercise in patients with total cavopulmonary connection (TCPC).Design: An observational study using the patients as their own controls.Setting: Using a combination of magnetic resonance (MR) phase contrast techniques and an MR compatible bicycle ergometer, blood flow was measured in the superior vena cava, the tunnel from the inferior vena cova, and in the left and right pulmonary arteries during rest and on exercise (0.5 W/kg and 1.0 W/kg).Patients: Eleven patients aged 11.4 (4.6) years (mean (SD)) were studied 6.3 (3.8) years after TCPC operation.Main outcome measures: Volume flow measured in all four branches of the TCPC connection during rest and exercise.Results: Systemic venous return (inferior vena cava plus superior vena cava) increased from 2.5 (0.1) 1/min/m(2) (mean (SEM)) to 4,4 (0.4) 1/min/m(2) (p < 0.05) during exercise, with even distribution to the two pulmonary arteries. At rest, inferior vena caval flow was higher than superior vena coval flow, at 1.4 (0.1) v 1.1 (0.1) 1/min/m(2) (p < 0.05), During exercise, inferior vena coval flow doubled (to 3.0 (0.3) 1/min/m(2)) while superior vena caval flow only increased slightly (to 1,4 (0.1) 1/min/m(2)) (p < 0.05). The increased blood flow mainly reflected an increase in heart rate, The inferior vena coval to superior vena caval flow ratio was 1.4 (0.1) at rest and increased to 1.8 (0.1) (p < 0.05) at 0.5 W/kg, and to 2.2 (0.2) at 1.0 W/kg (p < 0.05).Conclusions: Quantitative flow measurements can be performed immediately after exercise using MR techniques. Supine leg exercise resulted in a more than twofold increase in inferior vena caval flow. This was equally distributed to the two lungs, indicating that pulmonary resistance rather than geometry decides flow distribution in the TCPC circulation.