Right ventricular outflow tract systolic excursion: a distinguishing echocardiographic finding in acute pulmonary...

Even though chronic pulmonary hypertension (cPH) and acute pulmonary embolism (aPE) increase pulmonary vascular resistance and result in right ventricular (RV) dilatation and systolic dysfunction; both conditions operate through drastically different mechanisms. Unfortunately, simple echocardiographic examination might be insufficient to distinguish both entities. This study attempted to determine which objective measures would be useful in differentiating aPE from cPH.

Standard measures of main RV as well as RV outflow tract (RVOT) size and systolic performance calculations were retrospectively measured from 15 patients with confirmed aPE by chest computed tomography and compared with similar data collected from the same number of age-matched patients with moderate (mcPH), severe (scPH), and patients without PH.

Although a positive McConnell sign was seen in 60% of aPE patients and in 17% of the cPH patients, all aPE had a profound reduction in RVOT systolic excursion when compared with cPH patients. Furthermore, maximal tricuspid annular plane systolic excursion, velocity time integral of the RVOT ejection signal, end-systolic or end-diastolic RV to left ventricle (LV) dimension ratio were not useful to distinguish aPE from any of the 2 forms of cPH.

This study demonstrated that measurement of RVOT systolic excursion not only is feasible but also extremely useful in identifying aPE and it is particularly helpful in differentiating it from patients with either mcPH or scPH. This variable might be useful to estimate the global impairment in RV contractility and acute hemodynamic derangement seen in aPE.