Noninvasive assessment of pressure drop in mitral stenosis by Doppler ultrasound.

A noninvasive method is described for measuring the pressure drop across the mitral valve in mitral stensois by Doppler ultrasound. A maximum frequency estimator was used to record maximum velocity in the Doppler signal from the mitral jet. Provided the angle between the ultrasound beam and the maximum velocity is close to zero the pressure drop can be calculated directly. Good correlation was found between Doppler measurements and simultaneous pressure recordings during heart catheterisation in 10 patients. No false negative or false positive diagnoses of mitral stenosis were made among 55 patients (35 patients with mitral stenosis and 20 patients with other valve lesions). The measurements were easy to perform in most patients and the method seems well suited both to diagnose and to follow patients with mitral stenosis.