“近端等速表面积”法评估二尖瓣狭窄合并主动脉瓣反流患者的二尖瓣面积

The "proximal isovelocity surface area" method in assessing mitral valve area in patients with mitral stenosis and associated aortic regurgitation.

作者信息

Centamore G, Galassi A R, Evola R, Lupo L, Galassi A

机构信息

Divisione di Cardiologia Azienda Ospedaliera Cannizzaro, Catania.

出版信息

G Ital Cardiol. 1997 Feb;27(2):133-40.

PMID:9199948

Abstract

BACKGROUND

This study compares the mitral valve area determined by Doppler color mapping of the proximal isovelocity surface area (PISA) and by Doppler pressure half-time with that obtained by two-dimensional planimetry in patients affected by mitral stenosis, with and without associated aortic regurgitation. Pressure half-time frequently overestimates the mitral valve area in patients with mitral stenosis and associated aortic regurgitation. PISA is an alternative method for determining mitral valve area in mitral stenosis and is not influenced by regurgitant lesions.

METHODS

We studied 76 patients with mitral stenosis; aortic regurgitation > or = 2 was present in 24 patients. The PISA was recorded from the apex and the transmitral maximal flow rate, Q (ml/s), was calculated using the hemispheric equation Q = 2 pi R2 x AV x alpha/180, where R (cm) is the maximal radius of the PISA, AV (cm/s) is the aliasing velocity and alpha/180 is a correction factor accounting for the alpha inflow angle formed by the mitral leaflets. Mitral valve area, A (cm2), was calculated by continuity equation A = Q/V, where V (cm/s) is the peak transmitral flow velocity measured by continuous wave Doppler.

RESULTS

The mitral valve area by two-dimensional planimetry (range 0.5-2.4 cm2; mean 1.33 +/- 0.41 cm2) was consistent with both PISA (r = 0.83; SEE 0.23 cm2) and pressure half-time (r = 0.79; SEE 0.25 cm2) methods. Similar agreement was found for the 36 patients with mitral regurgitation and for the 30 patients in atrial fibrillation. However, in patients with aortic regurgitation > or = 2, pressure half-time overestimated two-dimensional and PISA determined mitral valve areas by 0.24 +/- 0.25 cm2 (p < 0.01).

CONCLUSIONS

In patients with mitral stenosis and significant aortic regurgitation, the PISA method is more accurate than pressure half-time in assessing mitral valve area. This method may be a reliable alternative when pressure half-time is affected by aortic regurgitation and two-dimensional planimetry images are unsuitable for anatomic evaluation.

摘要

背景

本研究比较了二尖瓣狭窄患者（伴或不伴主动脉瓣反流）通过近端等速表面积（PISA）的多普勒彩色图谱和多普勒压力减半时间测定的二尖瓣面积与二维平面测量法所测结果。在二尖瓣狭窄合并主动脉瓣反流的患者中，压力减半时间常常高估二尖瓣面积。PISA是测定二尖瓣狭窄时二尖瓣面积的另一种方法，且不受反流病变的影响。

方法

我们研究了76例二尖瓣狭窄患者；其中24例存在主动脉瓣反流≥2级。从心尖记录PISA，并使用半球方程Q = 2πR²×AV×α/180计算二尖瓣最大流速Q（ml/s），其中R（cm）是PISA的最大半径，AV（cm/s）是频谱峰值速度，α/180是一个校正因子，用于计算二尖瓣叶形成的α流入角。二尖瓣面积A（cm²）通过连续性方程A = Q/V计算得出，其中V（cm/s）是通过连续波多普勒测量的二尖瓣峰值流速。

结果

二维平面测量法测得的二尖瓣面积（范围0.5 - 2.4 cm²；平均1.33±0.41 cm²）与PISA法（r = 0.83；标准误0.23 cm²）和压力减半时间法（r = 0.79；标准误0.25 cm²）均相符。在36例二尖瓣反流患者和30例房颤患者中也发现了类似的一致性。然而，在主动脉瓣反流≥2级的患者中，压力减半时间法比二维平面测量法和PISA法测定的二尖瓣面积高估了0.24±0.25 cm²（p < 0.01）。