Jang Jeong Yoon, Kang Joon-Won, Yang Dong Hyun, Lee Sahmin, Sun Byung Joo, Kim Dae-Hee, Song Jong-Min, Kang Duk-Hyun, Song Jae-Kwan
Division of Cardiology, Department of Internal Medicine, Gyeongsang National University School of Medicine, Gyeongsang National University Changwon Hospital, Changwon, Korea.
Cardiac Imaging Center, Asan Medical Center Heart Institute, University of Ulsan College of Medicine, Seoul, Korea.
J Cardiovasc Ultrasound. 2018 Mar;26(1):33-39. doi: 10.4250/jcu.2018.26.1.33. Epub 2018 Mar 28.
Overestimation of the severity of mitral regurgitation (MR) by the proximal isovelocity surface area (PISA) method has been reported. We sought to test whether angle correction (AC) of the constrained flow field is helpful to eliminate overestimation in patients with eccentric MR.
In a total of 33 patients with MR due to prolapse or flail mitral valve, both echocardiography and cardiac magnetic resonance image (CMR) were performed to calculate regurgitant volume (RV). In addition to RV by conventional PISA (RV), convergence angle (α) was measured from 2-dimensional Doppler color flow maps and RV was corrected by multiplying by α/180 (RV). RV measured by CMR (RV) was used as a gold standard, which was calculated by the difference between total stroke volume measured by planimetry of the short axis slices and aortic stroke volume by phase-contrast image.
The correlation between RV and RV by echocardiography was modest [RV vs. RV (r = 0.712, < 0.001) and RV vs. RV (r = 0.766, < 0.001)]. However, RV showed significant overestimation (RV - RV = 50.6 ± 40.6 mL vs. RV - RV = 7.7 ± 23.4 mL, < 0.001). The overall accuracy of RV for diagnosis of severe MR, defined as RV ≥ 60 mL, was 57.6% (19/33), whereas it increased to 84.8% (28/33) by using RV ( = 0.028).
Conventional PISA method tends to provide falsely large RV in patients with eccentric MR and a simple geometric AC of the proximal constraint flow largely eliminates overestimation.
有报道称近端等速表面积（PISA）法会高估二尖瓣反流（MR）的严重程度。我们试图测试受限流场的角度校正（AC）是否有助于消除偏心MR患者中的高估现象。
总共33例因二尖瓣脱垂或连枷样二尖瓣导致MR的患者接受了超声心动图和心脏磁共振成像（CMR）检查，以计算反流容积（RV）。除了通过传统PISA法测得的RV（RV）外，还从二维多普勒彩色血流图测量了会聚角（α），并将RV乘以α/180进行校正（RV）。以CMR测得的RV（RV）作为金标准，其通过短轴切片面积测量法测得的总搏出量与相位对比图像测得的主动脉搏出量之差来计算。
超声心动图测得的RV与RV之间的相关性一般[RV与RV（r = 0.712，<0.001）以及RV与RV（r = 0.766，<0.001）]。然而，RV显示出明显高估（RV - RV = 50.6±40.6 mL对比RV - RV = 7.7±23.4 mL，<0.001）。对于诊断重度MR（定义为RV≥60 mL），RV的总体准确性为57.6%（19/33），而使用RV时增至84.8%（28/33）（P = 0.028）。
传统PISA法在偏心MR患者中往往会提供错误的大RV值，近端受限流场的简单几何AC在很大程度上消除了高估现象。
