VALIDATION OF CONTINUOUS-WAVE DOPPLER-DETERMINED RIGHT-VENTRICULAR PEAK POSITIVE AND NEGATIVE DP/DT - EFFECT OF RIGHT ATRIAL PRESSURE ON MEASUREMENT

Objectives. The present study aimed to validate the peak positive and negative values of the first derivative of right ventricular pressure (dP/dt) using Doppler echocardiography and to determine the impact of right atrial pressure on the measurements. Background. A pressure gradient between the right ventricle and the right atrium can be obtained by continuous wave Doppler-derived tricuspid regurgitant velocity using the simplified Bernoulli equation. If right atrial pressure fluctuation during systole and isovolumic diastole were small compared with right ventricular pressure changes, right ventricular pressure could be evaluated, and maximal positive and negative dP/dt could also be determined with Doppler echocardiography. Methods. We investigated 11 patients with a wide range of right atrial pressure with tricuspid regurgitation using simultaneous examination by Doppler ultrasound and catheterization. Hemodynamic conditions were altered by the Valsalva maneuver, and a total of 40 beats were analyzed. Results. There was good correlation between Doppler derived and catheterization derived peak positive dP/dt (y = 1,0x - 15.4, 0.98, n = 40), irrespective of the level of right atrial pressure. Doppler derived peak negative dP/dt also showed good correlation with that determined by catheterization (y = 0.9x + 58.2, 0.93, n = 40). However, in patients with high right atrial pressure (v wave pressure greater than or equal to 10 mm Hg), Doppler derived peak negative dP/dt tended to show lower values than those from catheterization measurements, except in patients with pulmonary hypertension. Conclusions. We conclude that right ventricular dP/dt can be estimated by the Doppler method accurately and noninvasively. However, when right atrial pressure is relatively high compared with corresponding right ventricular pressure changes during isovolumic diastole, Doppler derived peak negative dP/dt might underestimate catheter derived measurements.