Abstract 13827: Vector Velocity Imaging Differentiates Right Ventricular Dysfunction in RV Myocardial Infarction and Submassive Pulmonary Embolism

Abstract

Background: Submassive pulmonary embolism (SMPE) and right ventricular myocardial infarction (RVMI) may have similar clinical presentation. Recent studies suggest right ventricular dysfunction (RVD) on 2-D echocardiography (2DE) in both conditions can also be similar. Speckle tracking with vector velocity imaging (VVI) is a novel method to assess global and regional myocardial function, independent of tethering artifacts, inherent to 2DE. We hypothesized that assessment of RV myocardial strain by VVI can differentiate these conditions.

Methods: We compared 30 patients (63 ± 15 yrs, 11 women) with SMPE, confirmed by CT to 30 patients (52 ± 15 yrs, 15 women) with RVMI, confirmed by coronary angiography. 2DE was performed within 24 hours and VVI was performed off-line (TomTec). RV longitudinal global and segmental strains (ε) were obtained in apical 4 chamber view. PA pressure, RV end diastolic area (RVEDA) and RV fractional area change (RVFAC) was obtained per ASE guidelines.

Results: Global RV longitudinal ε and strain rate were similar in both groups (-12.9% ± 5 vs -13.1% ± 5, p=0.05 and -1.19 s^-1 ± 4 vs -0.9 s^-1 ± 3, p=0.05, in SMPE vs RVMI respectively). Regional RV ε exhibited distinctive reductions in both conditions. Basal free wall ε was reduced in SMPE (-13% ± 7 vs -19 ± 10, p= 0.01), whereas basal septal ε was reduced in RVMI group (-19% ± 13 vs -10 ± 7, p= 0.02). Other regional ε had no significant difference. RVEDA and PA pressure were higher, while RVFAC was lower in SMPE group (21 ± 8 vs 29 ± 11, p=0.02).

Conclusions: RV function quantification by VVI shows that although global RV ε were similar, there were significant reductions in individual segmental ε specific to each condition. SMPE resulted in reduced basal free wall ε, while RV MI affected basal septal strain. SMPE group also had reduced RV FAC in the presence of greater RV area. Therefore, we hypothesize that segmental RV strain calculated by VVI can provide a novel quantifiable marker to differentiate submassive PE from RV MI.