Enriquez-Sarano M, Sinak L J, Tajik A J, Bailey K R, Seward J B
Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA.
Circulation. 1995 Nov 15;92(10):2951-8. doi: 10.1161/01.cir.92.10.2951.
In patients with mitral valve prolapse, spontaneous changes of the effective regurgitant orifice during systole are not well documented. Such changes can now be analyzed by use of the proximal isovelocity surface area method, but the changes raise concern about the reliability of this method for assessing overall severity of regurgitation in these patients.
In a prospective study of 42 patients with mitral valve prolapse, the effective mitral regurgitant orifice was calculated at four phases of systole (early, mid, mid-late, and late) as the ratio of regurgitant flow to regurgitant velocity by use of the proximal isovelocity surface area method. Throughout systole, the effective regurgitant orifice increased significantly, from 32 +/- 27 mm2 in early systole to 41 +/- 27 in midsystole, 55 +/- 30 in mid-late systole, and 107 +/- 66 mm2 during late systole (P < .0001). Phasic regurgitant volume increased from early to mid-late systole but decreased in late systole. For quantitation of the overall effective regurgitant orifice, four approaches using the proximal isovelocity surface area were compared with simultaneously performed quantitative Doppler echocardiography (54 +/- 30 mm2) and quantitative two-dimensional echocardiography (51 +/- 29 mm2). All correlations were good (r > .95), but overestimation was considerable when the largest flow convergence was used (70 +/- 39 mm2; both P < .0001), significant when the simple mean of the four phases was used (59 +/- 36 mm2; P = .005 and P = .0007, respectively), mild when a weighted mean of the four phases was used (55 +/- 33 mm2; P = .41 and P = .01, respectively), and no overestimation was observed when the effective regurgitant orifice calculated at maximum regurgitant velocity was used (54 +/- 30 mm2; P = .29 and P = .17, respectively).
Phasic changes of mitral regurgitation are observed in patients with mitral valve prolapse. The effective regurgitant orifice increases throughout systole. Regurgitant volume also increases initially but tends to decrease in late systole. These changes can lead to overestimation of the overall degree of regurgitation, but properly timed measurements made by use of the proximal isovelocity surface area method allow an accurate estimation of the overall effective regurgitant orifice.
在二尖瓣脱垂患者中，收缩期有效反流口的自发变化尚无充分记录。现在可以使用近端等速表面积法分析此类变化，但这些变化引发了对该方法评估这些患者反流总体严重程度可靠性的担忧。
在一项对42例二尖瓣脱垂患者的前瞻性研究中，使用近端等速表面积法在收缩期的四个阶段（早期、中期、中晚期和晚期）计算二尖瓣有效反流口，计算方法为反流流量与反流速度之比。在整个收缩期，有效反流口显著增加，从收缩早期的32±27mm²增加到收缩中期的41±27mm²、收缩中晚期的55±30mm²以及收缩晚期的107±66mm²（P<.0001）。阶段性反流容积从收缩早期到收缩中晚期增加，但在收缩晚期减少。为了定量总体有效反流口，将使用近端等速表面积法的四种方法与同时进行的定量多普勒超声心动图（54±30mm²）和定量二维超声心动图（51±29mm²）进行比较。所有相关性都很好（r>.95），但使用最大血流汇聚时存在相当大的高估（70±39mm²；P均<.0001），使用四个阶段的简单平均值时存在显著高估（59±36mm²；P分别为.005和.0007），使用四个阶段的加权平均值时存在轻度高估（55±33mm²；P分别为.41和.01），而使用最大反流速度时计算的有效反流口则未观察到高估（54±30mm²；P分别为.29和.17）。
二尖瓣脱垂患者存在二尖瓣反流的阶段性变化。有效反流口在整个收缩期增加。反流容积最初也增加，但在收缩晚期趋于减少。这些变化可能导致对反流总体程度的高估，但使用近端等速表面积法进行适时测量可准确估计总体有效反流口。
