Aims: The relation of the extent of obstruction of the pulmonary vasculature in pulmonary embolism (PE) and impact on right ventricular (RV) hemodynamics is not well established. This study evaluated the relation of size of perfusion defects and changes in echocardiographic measures of global and regional RV dysfunction in 58 consecutive patients with non-massive PE.
Methods and results: Patients were compared with 58 age-matched controls that had normal ventilation/perfusion scintigraphies. A 2D, Doppler and Tissue Doppler echocardiography performed on the same day, quantified RV pressure and global and regional performance. Intermediate and large pulmonary emboli were associated with a significant impact on RV pressure and function. For small pulmonary emboli obstructing <25% of the pulmonary vasculature, the acceleration time of the pulmonary artery (PA) outflow was significantly shortened, 85 +/- 22 ms vs. 117 +/- 35 ms, P < 0.0001. Peak systolic strain in the middle segment of RV free wall was reduced in patients with perfusion defect greater than 25%, -1 +/- 13% vs. -13 +/- 17%, P < 0.001.
Conclusion: Mid ventricular longitudinal dysfunction consistent with the 'McConnell-sign' is found in patients with moderate degrees of perfusion defects, whereas the acceleration time of the PA flow is reduced even in patients with small pulmonary emboli.