[Severity of XXXX assessed by Doppler techniques].

@entity1 @entity64 @entity886 @entity472 @entity337 @entity1129 @entity850
Continuous wave (CW) Doppler ultrasound has facilitated accurate estimates of pressure gradient (PG) across a stenotic valve. However, the severity of @entity850 cannot be assessed using PG alone because it is dependent on actual flow across the valve. In this study, Doppler techniques were used to predict @entity886 (AVA) in adults with @entity472 ( @entity472 ). Fifty-four adult @entity1 undergoing cardiac catheterization for suspected @entity472 were prospectively evaluated. There were 28 @entity1 and 26 @entity1 , who ranged in age from 25 to 68 years with a mean of 56 years. These Doppler ultrasound studies were performed using a 2 MHz transducer and an Aloka SSD-730. With CW Doppler ultrasound, the highest velocities of the aortic jet were recorded from an apical approach. Left ventricular outflow flows were recorded about 1.0-1.5 cm below the aortic annulus using high PRF. Doppler waveforms were analyzed for the @entity1129 /ET ( @entity1129 : acceleration time, ET: ejection time), and Doppler PG was calculated from the maximum velocity (V) of the aortic jet based on a modified Bernoulli equation (PG = 4V2), and aortic valve area was obtained using the continuity equation-(AVA = left ventricular outflow tract @entity64 volume divided by @entity472 jet velocity integral). These data were compared with hemodynamic data obtained from cardiac catheterization. The following results were obtained: 1. In eight @entity1 with substantial @entity337 , whose maximum catheter PG were from 20 to 45 mmHg, the @entity1129 /ET was less than 0.30. The ratio of @entity1129 /ET correlated with the peak velocity of the aortic jet (r = 0.88) and the maximum PG (r = 0.87) obtained from cardiac catheterization. 2. In 46 @entity1 with @entity472 , the maximum PG by CW Doppler showed an excellent correlation with maximum catheterization PG (r = 0.97, SEE 6 mmHg), and the mean PG as calculated by the two techniques also disclosed a good correlation (r = 0.97, SEE 5.4 mmHg).(ABSTRACT TRUNCATED @entity1129 400 WORDS)
