Bernstein Frederic J, Badran Sarah, Takao Cheryl
Division of Pediatric Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, USA.
Pediatr Cardiol. 2012 Jan;33(1):15-20. doi: 10.1007/s00246-011-0057-y. Epub 2011 Jul 26.
Pulmonary artery wedge pressure (PAWp) as a surrogate for left atrial pressure (LAp) has been validated in patients with fully pulsatile two-ventricle circulations. This study was to validate PAWp as an accurate estimate of LAp for calculating pulmonary vascular resistance in single-ventricle patients after the bidirectional Glenn operation. A prospective study measuring direct branch pulmonary artery pressures, ipsilateral PAWp, and direct LAp to calculate pulmonary and systemic blood flows was conducted. Pulmonary vascular resistance (PVR) was calculated for each patient using the PAWp and compared to the PVR calculated by direct LAp measurements. Twenty-eight patients were enrolled; 27 were eligible for study inclusion. Ages ranged from 21 to 60 months and weights ranged from 9.5 to 20.8 kg. Underlying congenital heart defect diagnoses varied, with all patients either functionally or anatomically univentricular. Left mPAWp measured 4.4 ± 2.6, statistically different from simultaneous direct mLAp of 2.5 ± 2.4 mmHg (P < 0.001. Right mPAWp measured 4.3 ± 3.2 mmHg, statistically different from simultaneous direct mLAp of 2.8 ± 2.6 mmHg (P < 0.001. The PVR calculated using mPAWp was 1.2 ± 0.7 W.U., statistically different to 1.8 ± 0.95 W.U. using mLAp (P < 0.001). The average PVR measurement calculated using mPAWp underestimated the PVR calculated using mLAp by 0.6 W.U. It can be extrapolated that a PVR of 2.3 W.U. calculated using wedge measurements would estimate a PVR of 3 W.U. calculated using direct LA measurements. In this study, the PVR calculated using PAWp as a surrogate for LAp either equaled or underestimated the true PVR, up to 33% different. This difference is important in patients with univentricular physiology who rely on low PVR for cardiac output. Thus, based on this study, a PVR measurement of greater than 2.3 W.U. by the mPAWp method should prompt a direct LA pressure measurement, in order to more appropriately determine true surgical risk.
肺动脉楔压（PAWp）作为左心房压力（LAp）的替代指标，已在具有完全搏动性双心室循环的患者中得到验证。本研究旨在验证PAWp能否准确估算双向格林手术术后单心室患者的LAp，用于计算肺血管阻力。开展了一项前瞻性研究，测量直接分支肺动脉压力、同侧PAWp和直接LAp以计算肺循环和体循环血流量。使用PAWp为每位患者计算肺血管阻力（PVR），并与通过直接测量LAp计算出的PVR进行比较。共纳入28例患者，其中27例符合研究纳入标准。年龄范围为21至60个月，体重范围为9.5至20.8千克。潜在的先天性心脏病诊断各异，所有患者在功能或解剖学上均为单心室。左平均PAWp为4.4±2.6，与同时测量的直接左平均LAp 2.5±2.4 mmHg有统计学差异（P<0.001）。右平均PAWp为4.3±3.2 mmHg，与同时测量的直接右平均LAp 2.8±2.6 mmHg有统计学差异（P<0.001）。使用平均PAWp计算的PVR为1.2±0.7 Wood单位，与使用平均LAp计算的1.8±0.95 Wood单位有统计学差异（P<0.001）。使用平均PAWp计算的PVR测量值比使用平均LAp计算的PVR低估了0.6 Wood单位。由此推断，使用楔压测量计算出的2.3 Wood单位的PVR将估算出使用直接LA测量计算出的3 Wood单位的PVR。在本研究中，使用PAWp替代LAp计算的PVR等于或低估了真实的PVR，差异高达33%。这种差异对于依赖低PVR来维持心输出量的单心室生理患者很重要。因此，基于本研究，通过平均PAWp方法测量的PVR大于2.3 Wood单位时，应促使进行直接LA压力测量，以便更恰当地确定真正的手术风险。
