Hjortdal V E, Emmertsen K, Stenbøg E, Fründ T, Schmidt M Rahbek, Kromann O, Sørensen K, Pedersen E M
Department of Cardiothoracic and Vascular Surgery, Skejby Hospital, Aarhus University Hospital, DK-8200 Aarhus N, Denmark.
Circulation. 2003 Sep 9;108(10):1227-31. doi: 10.1161/01.CIR.0000087406.27922.6B. Epub 2003 Aug 25.
Little is known about blood flow and its relationship to respiration during exercise in patients with total cavopulmonary connection (TCPC).
We studied 11 patients 12.4+/-4.6 years (mean+/-SD) of age 5.9+/-2.8 years (mean+/-SD) after TCPC operation. Real-time MRI was used to measure blood flow in the superior vena cava (SVC), inferior vena cava (IVC), and ascending aorta under inspiration and expiration during supine lower-limb exercise (rest, 0.5 and 1.0 W/kg) on an ergometer bicycle. IVC and aortic flow increased from 1.60+/-0.52 and 2.99+/-0.83 L/min per m2 at rest to 2.58+/-0.71 and 3.97+/-1.20 L/min per m2 at 0.5 W/kg and to 3.25+/-1.23 and 4.62+/-1.49 L/min per m2 at 1.0 W/kg (P< or =0.05). SVC flow remained unchanged. Resting flow in the IVC was greater during inspiration (2.99+/-1.25 L/min per m2) than during expiration (0.83+/-0.44 L/min per m2) (inspiratory/mean flow ratio, 1.9+/-0.5), and retrograde flow was present during expiration (11+/-12% of mean flow). The predominance of inspiratory flow in IVC diminished with exercise to an inspiratory/mean flow ratio of 1.5+/-0.2 (P< or =0.05) and 1.4+/-0.3 at 0.5 and 1.0 W/kg, respectively.
In the TCPC, circulation IVC and aortic but not SVC flows increase with supine leg exercise. Inspiration facilitates IVC flow at rest but less so during exercise, when the peripheral pump seems to be more important.
关于完全性腔肺连接（TCPC）患者运动期间的血流及其与呼吸的关系，目前所知甚少。
我们研究了11例年龄为12.4±4.6岁（平均±标准差）、在TCPC手术后5.9±2.8年（平均±标准差）的患者。在卧式测力计自行车上进行下肢运动（休息、0.5和1.0W/kg）时，使用实时磁共振成像测量仰卧位吸气和呼气时上腔静脉（SVC）、下腔静脉（IVC）和升主动脉的血流。IVC和主动脉血流从休息时的每平方米1.60±0.52和2.99±0.83L/min增加到0.5W/kg时的每平方米2.58±0.71和3.97±,1.20L/min，以及1.0W/kg时的每平方米3.25±1.23和4.62±1.49L/min（P≤0.05）。SVC血流保持不变。IVC的静息血流在吸气时（每平方米2.99±1.25L/min）大于呼气时（每平方米0.83±0.44L/min）（吸气/平均血流比，1.9±0.5），呼气时存在逆流（平均血流的11±12%）。IVC吸气血流优势随着运动减弱，在0.5和1.0W/kg时吸气/平均血流比分别为1.5±0.2（P≤0.05）和1.4±0.3。
在TCPC患者中，仰卧位腿部运动时IVC和主动脉循环血流增加，但SVC血流未增加。吸气在休息时促进IVC血流，但在运动时作用较小，此时外周泵似乎更为重要。
