Comparison of Doppler-derived pressure gradient to that determined at cardiac catheterization in adults with aortic valve stenosis: implications for management.

Over a 1-year period cardiac catheterization was performed in 58 patients, mean age 66 years, who had elevated aortic blood flow velocity (more than 1.7 m/s) by continuous-wave Doppler echocardiography. Doppler echo signals were initially judged acceptable for quantitative analysis in 95% of patients, usually from the apical transducer position.

Effect of variation in PQ interval on patterns of atrioventricular valve motion and flow in patients with normal ventricular function.

M-mode echocardiography and Doppler ultrasonography were used to study patterns of atrioventricular (AV) valve motion and flow in five patients with complete heart block, normal ventricular function and an implanted dual chamber pacemaker with programmable PQ intervals. Changes in AV valve motion and flow patterns resulting from steady state changes in PQ interval over the range studied (75 to 250 ms) were similar in all patients. Events reflecting AV valve opening and rapid ventricular filling bore a constant temporal relation to the Q wave and were unaffected by changes in PQ interval.

Noninvasive evaluation of intracardiac pressures using Doppler ultrasound: a case study of panvalvular regurgitation.

Doppler velocity signals from regurgitant valve flow can be used to calculate pressure gradients across incompetent valves by a modification of the Bernoulli equation. Analysis of these gradients provides clinically useful, noninvasive information about cardiac chamber pressures. This study presents an unusual case of cardiomyopathy with panvalvular regurgitation which demonstrates the major methods of pressure analysis using Doppler signals from regurgitant valves.

The accuracy of Doppler ultrasound measurement of pressure gradients across irregular, dual, and tunnellike obstructions to blood flow.

The accuracy of Doppler-estimated pressure gradients in the setting of irregular, multiple, and tunnellike stenoses was investigated. An in vitro model of the left ventricular outflow tract was designed to allow pulsatile flow of red cells in saline across valve orifices from 0.01 to 2.

Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation.

We evaluated the accuracy of a noninvasive method for estimating right ventricular systolic pressures in patients with tricuspid regurgitation detected by Doppler ultrasound. Of 62 patients with clinical signs of elevated right-sided pressures, 54 (87%) had jets of tricuspid regurgitation clearly recorded by continuous-wave Doppler ultrasound. By use of the maximum velocity (V) of the regurgitant jet, the systolic pressure gradient (delta P) between right ventricle and right atrium was calculated by the modified Bernoulli equation (delta P = 4V2).