Pearson A C, St Vrain J, Mrosek D, Labovitz A J
Department of Internal Medicine, St. Louis University School of Medicine, Missouri.
J Am Coll Cardiol. 1990 Jul;16(1):232-9. doi: 10.1016/0735-1097(90)90483-6.
Chordal rupture with a subsequent flail mitral valve leaflet is now the most common cause of pure mitral regurgitation. To describe the Doppler color flow findings in flail mitral leaflet and the determinants of these findings, Doppler color flow mapping and conventional Doppler echocardiography were performed in 31 consecutive patients presenting with a flail mitral leaflet. In the 23 patients with a posterior flail leaflet, a distinctive highly eccentric and turbulent jet directed toward the posterior wall of the aorta was noted. In the eight patients with an anterior flail leaflet, a jet directed toward the posterolateral left atrial wall was noted. Maximal regurgitant jet area was significantly larger in patients with a flail anterior leaflet (13.1 +/- 3.0 cm2) than in those with a flail posterior leaflet (5.8 +/- 3.0 cm2, p = 0.0001). Maximal jet area to left atrial ratio was also significantly higher in those with a flail anterior leaflet (0.56 +/- 0.16) than in those with a flail posterior leaflet (0.27 +/- 0.17, p = 0.0006). When systolic left atrial velocities encoded as red were incorporated into the maximal jet area measurement, 7 of the 8 patients with an anterior flail leaflet had a jet area greater than 8 cm2, consistent with severe mitral regurgitation, compared with 13 of the 23 patients with a flail posterior leaflet. There was no correlation between jet area or jet area to left atrial ratio and any hemodynamic variable. Patients with acute mitral regurgitation exhibited a trend toward smaller jet areas, but this did not reach statistical significance. Regurgitant fraction calculated from pulsed Doppler recording of mitral and aortic flow was consistent with moderately severe or severe mitral regurgitation in all cases and averaged 70%. Thus, patients with a flail mitral valve leaflet have distinctive Doppler color flow findings. A highly eccentric and turbulent jet directed posteriorly to the aorta may contribute to a systematic underestimation of severe mitral regurgitation by conventional Doppler color flow criteria. The use of pulsed Doppler ultrasound to calculate regurgitant fraction in patients with a flail mitral valve leaflet may be helpful in reliably assessing the degree of mitral regurgitation.
腱索断裂伴随后的连枷样二尖瓣叶目前是单纯二尖瓣反流最常见的原因。为描述连枷样二尖瓣叶的多普勒彩色血流表现及其决定因素，对31例连续出现连枷样二尖瓣叶的患者进行了多普勒彩色血流图和传统多普勒超声心动图检查。在23例后叶连枷的患者中，观察到一股独特的高度偏心且紊乱的血流束射向主动脉后壁。在8例前叶连枷的患者中，观察到一股血流束射向左心房后壁。前叶连枷患者的最大反流束面积（13.1±3.0cm²）显著大于后叶连枷患者（5.8±3.0cm²，p=0.0001）。前叶连枷患者的最大反流束面积与左心房面积之比（0.56±0.16）也显著高于后叶连枷患者（0.27±0.17，p=0.0006）。当将编码为红色的收缩期左心房速度纳入最大反流束面积测量时，8例前叶连枷患者中有7例的反流束面积大于8cm²，符合重度二尖瓣反流，而后叶连枷的23例患者中有13例如此。反流束面积或反流束面积与左心房面积之比与任何血流动力学变量均无相关性。急性二尖瓣反流患者的反流束面积有变小的趋势，但未达到统计学意义。根据二尖瓣和主动脉血流的脉冲多普勒记录计算的反流分数在所有病例中均符合中度重度或重度二尖瓣反流，平均为70%。因此，连枷样二尖瓣叶患者有独特的多普勒彩色血流表现。一股高度偏心且紊乱的血流束向后射向主动脉可能导致按照传统多普勒彩色血流标准对重度二尖瓣反流的系统性低估。使用脉冲多普勒超声计算连枷样二尖瓣叶患者的反流分数可能有助于可靠地评估二尖瓣反流程度。
