Right ventricular outflow tract spectral signal: a useful marker of right ventricular systolic performance and pulmonary hypertension severity

Right ventricular outflow tract (RVOT) acceleration shortens with chronic pulmonary hypertension (cPH). However, the overall value of this spectral Doppler signal in the assessment of PH patients is not well understood. Markers of RV systolic performance, time to onset, time to peak, and total duration of the RVOT systolic spectral Doppler signal were examined. Group I consisted of 28 patients without PH [50 +/- 15 years and mean pulmonary artery systolic pressure (PASP) of 30 +/- 8 mmHg] and Group II included 52 patients with cPH (56 +/- 14 years and mean PASP of 80 +/- 27 mmHg; P < 0.0001). As expected, Group II patient's markers showed worse RV performance. In addition, Group II had a longer time to onset, a shorter time to peak, and a shorter total duration of the RVOT systolic signal than Group I. Both time to onset (r = 0.66 vs. r = -0.53; P < 0.0001) and time to peak (r = 0.65 vs. r = 0.50; P < 0.0001) of the RVOT signal correlated better with PH than RV fractional area change. Conversely, RV fractional area change correlated better with total duration of RVOT ejection (r = 0.66 vs. r = 0.58; P < 0.0001) than with PASP. Timing of onset and peak of the RVOT systolic spectral signal appears to be useful in characterizing the severity of the PASP, while the total duration of RVOT ejection is a better predictor of the systolic performance of the RV in PH patients. More studies are now required to determine the clinical utility of prospectively measuring RVOT in cPH.