Maslow A D, Haering J M, Heindel S, Mashikian J, Levine R, Douglas P
Departments of Anesthesia and Cardiology, Beth Israel-Deaconess Medical Center. Mass General Hospital, Boston, MA, USA.
Anesth Analg. 2000 Sep;91(3):509-16. doi: 10.1097/00000539-200009000-00002.
The conventional continuity equation uses nonsimultaneous measurements of blood flow velocities through the left ventricular outflow tract and across the aortic valve to calculate aortic valve area (AVA). We have noted that both velocities can be simultaneously obtained from continuous wave (CW) Doppler analysis (double-envelope [DE]). We hypothesize that prosthetic AVA can be calculated by using the DE technique, during transesophageal echocardiography (TEE). Prosthetic AVA was calculated in 41 of 45 patients immediately after aortic valve replacement by using the DE/AVA technique. Left ventricular outflow tract diameter was obtained from an esophageal view, while subvalvular (V(1)) and valvular (V(2)) peak velocities were simultaneously obtained from transgastric views by using CW Doppler. Prosthetic AVA and V(1)/V(2) ratio (Doppler velocity index) were calculated. V(1) was also measured by using pulse wave Doppler, as is conventionally done. Twenty-three Carbomedic (CM) and 18 Carpentier-Edwards (CE) AVA were evaluated. DE/AVAs for CM and CE valves correlated and agreed with that reported by the manufacturer (CM r(2) = 0.91, mean bias -0.25 cm(2) [SD 0.18]; CE r(2) = 0.73, mean bias -0.02 cm(2) [SD 0.27]). Calculated Doppler velocity index values agree with available data (mean bias 0.03 [SD 0.05]). The V(1) obtained by using the DE method was nearly identical to the V(1) obtained by using pulse wave (r(2) = 0.95, mean bias 0.02 m/s [SD 0.04 m/s]). TEE assessment of prosthetic AVA using the DE technique agrees with data reported by the manufacturer. Obtaining subvalvular and valvular velocities from the same CW Doppler trace may simplify the continuity equation and help avoid errors caused by beat-to-beat changes in blood flow. Quantitative prosthetic aortic valve assessment can be performed, on-line, with TEE by using the DE technique.
Quantitative assessment of prosthetic aortic valve area can be performed on-line by using transesophageal echocardiography using the double envelope technique.
传统的连续性方程通过非同步测量经左心室流出道和主动脉瓣的血流速度来计算主动脉瓣面积（AVA）。我们注意到这两个速度可通过连续波（CW）多普勒分析（双包络 [DE]）同时获得。我们假设在经食管超声心动图（TEE）检查期间，可使用DE技术计算人工瓣膜AVA。在45例患者中的41例主动脉瓣置换术后立即使用DE/AVA技术计算人工瓣膜AVA。从食管视图获取左心室流出道直径，同时通过使用CW多普勒从经胃视图同步获取瓣下（V(1)）和瓣膜（V(2)）峰值速度。计算人工瓣膜AVA和V(1)/V(2)比值（多普勒速度指数）。V(1)也按常规方法使用脉冲波多普勒测量。评估了23个Carbomedic（CM）瓣膜和18个Carpentier-Edwards（CE）瓣膜的AVA。CM和CE瓣膜的DE/AVA与制造商报告的数据相关且一致（CM r(2) = 0.91，平均偏差 -0.25 cm² [标准差0.18]；CE r(2) = 0.73，平均偏差 -0.02 cm² [标准差0.27]）。计算出的多普勒速度指数值与现有数据一致（平均偏差0.03 [标准差0.05]）。使用DE方法获得的V(1)与使用脉冲波获得的V(1)几乎相同（r(2) = 0.95，平均偏差0.02 m/s [标准差0.04 m/s]）。使用DE技术通过TEE评估人工瓣膜AVA与制造商报告的数据一致。从相同的CW多普勒迹线获取瓣下和瓣膜速度可能会简化连续性方程，并有助于避免因逐搏血流变化引起的误差。使用DE技术可通过TEE在线进行人工主动脉瓣的定量评估。
使用双包络技术通过经食管超声心动图可在线进行人工主动脉瓣面积的定量评估。
