Mego D M, Johns J P, Rubal B J
Cardiolgy Service, Brooke Army Medical Center, Fort Sam Houston, TX 78234-6200.
J Am Soc Echocardiogr. 1993 Mar-Apr;6(2):142-8. doi: 10.1016/s0894-7317(14)80484-7.
In patients with combined mitral stenosis (MS) and aortic regurgitation (AR), the Doppler-determined mitral valve area (MVA) may be overestimated due to a shorter than expected pressure half-time. We performed Doppler echocardiography at baseline and after inhalation of amyl nitrite in 10 patients with combined MS and AR (Group I) and in five patients with MS alone (Group II). AR severity was reduced by amyl nitrite inhalation in all Group I patients, with a decrease in mean jet height/LVOT ratio from 32% to 21% (p < 0.01). Pressure half-time increased in Group I after amyl nitrite, with a mean reduction in the calculated MVA of 0.15 cm2 (p < 0.01). Group II had no significant changes in pressure half-time or Doppler-determined MVA after amyl nitrite, whereas both groups had comparable increases in heart rate, mean transmitral velocity, and mean transmitral pressure gradient. In patients with combined MS and AR, we conclude that amyl nitrite significantly increases pressure half-time while reducing the severity of AR. These findings support earlier reports of MVA overestimation when pressure half-time is used in the presence of AR.
在二尖瓣狭窄（MS）合并主动脉瓣反流（AR）的患者中，由于压力减半时间短于预期，经多普勒测定的二尖瓣面积（MVA）可能会被高估。我们对10例MS合并AR患者（I组）和5例单纯MS患者（II组）在基线时以及吸入亚硝酸异戊酯后进行了多普勒超声心动图检查。I组所有患者吸入亚硝酸异戊酯后AR严重程度降低，平均射流高度/LVOT比值从32%降至21%（p<0.01）。I组吸入亚硝酸异戊酯后压力减半时间增加，计算出的MVA平均降低0.15 cm²（p<0.01）。II组吸入亚硝酸异戊酯后压力减半时间或经多普勒测定的MVA无显著变化，而两组的心率、平均二尖瓣流速和平均二尖瓣压力梯度均有类似增加。我们得出结论，在MS合并AR的患者中，亚硝酸异戊酯可显著增加压力减半时间，同时降低AR的严重程度。这些发现支持了早期关于在存在AR时使用压力减半时间会高估MVA的报道。
