Respiratory Effects on Fontan Circulation During Rest and Exercise Using Real-Time Cardiac Magnetic Resonance Imaging
Respiratory Effects on Fontan Circulation During Rest and Exercise Using Real-Time Cardiac Magnetic Resonance Imaging
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DOI：
10.1016/j.athoracsur.2015.11.011
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发表时间：
2016-05-01
影响因子：
4.6
通讯作者：
Yoganathan, Ajit P.
中科院分区：
文献类型：
--
作者：
Wei, Zhenglun;Whitehead, Kevin K.;Yoganathan, Ajit P.
背景。呼吸调节腔隙肺流量是已知的，但很少有数据比较屏气和自由呼吸条件下的平均流量，以分离呼吸效应和运动对呼吸调节的影响。采用实时相位对比磁共振结合一种新的呼吸跟踪方法，在相同的图像采集中研究呼吸在屏气、自由呼吸和运动条件下对Fontan腔静脉和主动脉血流的影响。采用基于热平均流量的呼吸相性指数来量化呼吸效应。在自由呼吸和运动条件下，下腔静脉（吸气/呼气：1.6 +/- 0.5和1.8 +/- 0.5）和上腔静脉（吸气/呼气：1.9 +/- 0.6和2.6 +/- 2.0）吸气时的流量都明显高于呼气。这些血管的呼吸相位性指数从休息到运动的变化进一步显示了呼吸的影响。全系统静脉流量在屏气和自由呼吸条件下无统计学差异。此外，在静息和运动条件下，降主动脉和下腔静脉的平均血流无显著差异。本研究表明，下腔静脉和上腔静脉血流时间变化主要由呼吸效应主导，可通过呼吸相性指数来检测。然而，呼吸对净流量的最小影响验证了常规使用屏气技术来测量Fontan患者的平均流量。此外，下腔静脉和降主动脉的平均血流是可互换的。(C) 2016年由胸外科学会发布
Background. It is known that respiration modulates cavopulmonary flows, but little data compare mean flows under breath-holding and free-breathing conditions to isolate the respiratory effects and effects of exercise on the respiratory modulation.Methods. Real-time phase-contrast magnetic resonance combined with a novel method to track respiration on the same image acquisition was used to investigate respiratory effects on Fontan caval and aortic flows under breath-holding, free-breathing, and exercise conditions. Respiratory phasicity indices that were based on beat-averaged flow were used to quantify the respiratory effect.Results. Flow during inspiration was substantially higher than expiration under the free-breathing and exercise conditions for both inferior vena cava (inspiration/expiration: 1.6 +/- 0.5 and 1.8 +/- 0.5, respectively) and superior vena cava (inspiration/expiration: 1.9 +/- 0.6 and 2.6 +/- 2.0, respectively). Changes from rest to exercise in the respiratory phasicity index for these vessels further showed the impact of respiration. Total systemic venous flow showed no significant statistical difference between the breath-holding and free-breathing conditions. In addition, no substantial difference was found between the descending aorta and inferior vena cava mean flows under either resting or exercise conditions.Conclusions. This study demonstrated that inferior vena cava and superior vena cava flow time variance is dominated by respiratory effects, which can be detected by the respiratory phasicity index. However, the minimal respiration influence on net flow validates the routine use of breath-holding techniques to measure mean flows in Fontan patients. Moreover, the mean flows in the inferior vena cava and descending aorta are interchangeable. (C) 2016 by The Society of Thoracic Surgeons