Abstract 12729: Duration of Right to Left Ventricular Outflow Tract Ejection Spectral Doppler Ratio: A Potential Index of Ejection Dyssynchrony in Chronic Pulmonary Hypertension
Background: Several studies using tissue Doppler imaging have demonstrated the presence of right ventricular (RV) mechanical dyssynchrony in patients with chronic pulmonary hypertension (cPH). Unfortunately, not all echo labs are equipped with sophisticated imaging tools to make such determinations. Consequently, we devised a study to assess if pulsed Doppler interrogation of the RV and left ventricular outflow tract (LVOT) signals can identify temporal differences in systolic ejection between the two ventricles as a Results on cPH.
Methods: Since cPH delays pulmonic closure resulting in a closely split second heart sound, we measured velocity time integrals and total duration of LVOT and RVOT ejection using pulsed Doppler signals as well as standard measures of RV and LV performance from 70 patients divided into two groups. Group I included 30 patients (53 ± 7 years) without PH (31 ± 5 mmHg) and Group II comprised 40 patients (53 ± 13 years; P=NS) with cPH (82 ± 24 mmHg; p<0.00001).
Results: As expected, Group II patients had worse RV fractional area change (37 ± 18% vs. 62 ± 10; p<0.0001), smaller RVOT Doppler velocity time integrals (0.14 ± 0.05 cm vs. 0.17 ± 0.03 cm; p<0.01) and similar LV ejection fraction (78 ± 10% vs. 74 ± 8%; p=NS) than Group I patients. Furthermore, Group II patients had a significantly smaller RVOT-LVOT duration of ejection ratio as seen in Figure 1A. Finally, a good positive correlation was seen between the magnitude of pulmonary pressure and this RVOT-LVOT duration of ejection ratio (Figure 1B).
Conclusions: Duration of RV to LV ejection ratio, obtained using standard pulsed Doppler, not only explains auscultatory findings in cPH patients but also appears useful in identifying temporal differences in terms of systolic ejection between the two ventricles. A prospective study is now required to correlate this ratio of ejection dyssynchrony with clinical outcomes in cPH patients.
- © 2010 by American Heart Association, Inc.