DEPARTMENT OF ECHOCARDIOGRAPHY, SHAHEED RAJAIE CARDIOVASCULAR MEDICAL AND RESEARCH CENTER, TEHRAN, IRAN
ackground- Several well-established echocardiographic parameters such as tricuspid annular plane systolic excursion (TAPSE), right ventricular outflow tract (RVOT) fractional shortening (FS), myocardial performance index, and Doppler tissue imaging have been used for the assessment of right ventricular (RV) performance. The aim of this study was to evaluate the response of various parameters of RV function to dobutamine infusion in healthy individuals.
Methods- Thirty-eight participants with negative dobutamine stress testing for the left ventricle and with a mean age of 57 years (range: 40-85 yrs) underwent echocardiography, including measurement of TAPSE, fractional shortening (FS), and TDI (S velocity, strain and strain rate of base, mid, and apex) of the right ventricle at rest and after dobutamine infusion according to standard dobutamine stress testing (DSE) for the evaluation of changes in RV function after DSE.
Results- There were significant increases in S velocity (61.1%, P<0.001), FS (19.7%, P<0.001), TAPSE (6.4%, PV=0.026), strain rate (SR) in base (201%), apex (114%) and mid-wall (71%, all P<0.001), and strain in the apical portion (21%, PV=0.001) after dobutamine. There was no significant difference in SR between the RV free wall segments, but strain at mid-segment was more than that in the apical and basal segments at rest.
Conclusion- All RV performance parameters increased with the infusion of dobutamine. The mean values for strain rate were homogenous in basal, mid, and apical segments at rest and significantly increased in all the segments. This was in marked contrast to mean strain values, which were greatest in the mid part of the RV free wall at rest and increased only in the apical segment after DSE.