Pu M, Prior D L, Fan X, Asher C R, Vasquez C, Griffin B P, Thomas J D
Cardiovascular Imaging Center, Department of Cardiology, The Cleveland Clinic Foundation, Ohio 44195-5064, USA.
J Am Soc Echocardiogr. 2001 Mar;14(3):180-5. doi: 10.1067/mje.2001.110139.
To validate a previously proposed simplified proximal flow convergence method for calculating mitral regurgitant orifice area (ROA), a prospective study was conducted in ambulatory patients and in patients undergoing open heart surgery. Assuming a pressure difference between the left ventricle and left atrium of approximately 100 mm Hg (jet velocity [v(p)] 500 cm/s) and setting the color aliasing velocity (v(a)) to 40 cm/s, we simplified the conventional proximal convergence method formula (ROA = 2pi(r2)v(a)/v(p)) to r2/2, where r is the radius of the proximal convergence isovelocity hemisphere. For 57 ambulatory patients with a wide range of mitral regurgitant severity (1 to 4+), ROA was calculated by the conventional (x) and simplified (y) methods, demonstrating excellent accuracy (r = 0.92; P <.001; DeltaROA [y - x] = 0.004 +/- 0.08 cm2). For 24 intraoperative patients, ROA calculated by the simplified formula (y) correlated well with the pulsed Doppler-thermodilution method (x) (r = 0.84; P <.01; DeltaROA [y - x] = -0.002 +/- 0.08cm2). This simplified proximal convergence formula yields an accurate assessment of ROA for a wide range of regurgitant severity, while the time required for this measurement is shortened by half (1.5 +/- 0.5 minutes versus 3.2 +/- 0.7 minutes). This may increase the frequency of calculating ROA in the clinical laboratory.
为验证先前提出的用于计算二尖瓣反流口面积（ROA）的简化近端血流会聚法，我们对门诊患者和接受心脏直视手术的患者进行了一项前瞻性研究。假设左心室与左心房之间的压力差约为100 mmHg（射流速度[v(p)]为500 cm/s），并将彩色血流频谱的速度（v(a)）设置为40 cm/s，我们将传统的近端血流会聚法公式（ROA = 2π(r2)v(a)/v(p)）简化为r2/2，其中r为近端血流会聚等速半球的半径。对于57例二尖瓣反流严重程度范围较广（1至4+）的门诊患者，采用传统方法（x）和简化方法（y）计算ROA，结果显示二者具有极高的准确性（r = 0.92；P <.001；ΔROA [y - x] = 0.004 ± 0.08 cm2）。对于24例术中患者，采用简化公式（y）计算的ROA与脉冲多普勒 - 热稀释法（x）计算的结果具有良好的相关性（r = 0.84；P <.01；ΔROA [y - x] = -0.002 ± 0.08 cm2）。这种简化的近端血流会聚公式能够对广泛的反流严重程度准确评估ROA，同时该测量所需时间缩短了一半（分别为1.5 ± 0.5分钟和3.2 ± 0.7分钟）。这可能会增加临床实验室计算ROA的频率。
