Doppler ultrasound in mitral stenosis. Assessment of pressure gradient and atrioventricular pressure half-time.

In 16 patients with mitral stenosis (MS), alone or in combination with either mitral insufficiency (2 pats.) or aortic valve disease (3 pats.), the mean diastolic pressure gradients across the mitral valve calculated by Doppler ultrasound were significantly correlated to the catheterization data. The average mean pressure drop by Doppler was 11.8 mmHg and by catheterization at rest 16.7 mmHg. A significant correlation between gradients was also found in 5 patients who exercised supine on a bicycle. Atrioventricular pressure half-time (T1/2), i.e. the time during which the pressure drops from the peak value to half of its initial value by the Doppler technique, was significantly correlated to mitral valve area (MVA) determined from catheterization data. Increasing T1/2 reflected decreasing MVA. It is concluded that Doppler ultrasound is a useful method in the evaluation of patients with MS.