Transesophageal echocardiographic evaluation of native aortic valve area: utility of the double-envelope technique.
OBJECTIVE
To assess the accuracy of aortic valve area (AVA) calculations using the continuity equation with data obtained from the double envelope (DE) (simultaneously obtained left ventricular outflow tract [V1]) and aortic valve [V2] velocities) during intraoperative transesophageal echocardiography (TEE).


METHODS
Prospective study; measurements were performed on-line.


METHODS
University hospital.


METHODS
Cardiac and noncardiac surgical patients (n = 75) with recent aortic valve assessment (<3 months) undergoing general anesthesia or endotracheal intubation.


METHODS
Intraoperative AVA was measured by the continuity equation using the DE technique (DE/TEE) and by planimetry (PL/TEE). Left ventricular outflow tract diameter was obtained from midesophageal views, whereas subvalvular (V1) and valvular (V2) velocities were obtained simultaneously using continuous-wave Doppler from transgastric views. V1 was also obtained using pulsed-wave Doppler. Measurements were compared with AVA obtained preoperatively by the Gorlin equation during cardiac catheterization (G/CATH) or by transthoracic echocardiography using the traditional continuity equation (C/TTE) (nonsimultaneously obtained V1 and V2).


RESULTS
A DE was obtained in 73 of 75 patients (97%). Four patients had atrial fibrillation at the time of the examination, whereas the rest were in sinus rhythm. PL/TEE was performed in 54 of 71 patients with sinus rhythm (76%). Agreement was good between DE/TEE and G/CATH (mean bias, 0.02 cm(2) [SD, 0.24 cm(2)]), and C/TTE (mean bias, -0.05 cm(2) [SD, 0.16 cm(2)]). Agreement was not as good between PL/TEE and G/CATH (mean bias, -0.07 cm(2) [SD, 0.28 cm(2)]) and C/TTE (mean bias, -0.13 cm(2) [SD, 0.30 cm(2)]). V1 obtained by pulsed-wave Doppler and with DE closely agreed (mean bias, 0.01 m/sec [SD, 0.05 m/sec]).


CONCLUSIONS
TEE evaluation of native AVA using the DE technique is feasible and in good agreement with that obtained by C/TTE and G/CATH. Compared with DE/TEE, PL/TEE did not agree as well. Use of DE/TEE should simplify the continuity equation and may minimize errors resulting from beat-to-beat variability in stroke volume.
Maslow
A D
AD
Departments of Anesthesia and Cardiology, Beth Israel-Deaconess Medical Center, Boston, MA, USA.
Mashikian
J
J
Haering
J M
JM
Heindel
S
S
Douglas
P
P
Levine
R
R
D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging*; D003326:Coronary Circulation / Q000502:physiology; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011446:Prospective Studies; D016277:Ventricular Function, Left