title: Relationship between tissue Doppler-derived RV systolic function and invasive hemodynamic measurements.
abstract: Tissue Doppler imaging (TDI) is effective in assessing right ventricular (RV) function, but the relationship between invasive measurements and RV-TDI remains unclear. We investigated the RV systolic function by using the TDI-derived systolic myocardial (Sa) velocity and myocardial performance index (MPI). Beagles (n = 7) were anesthetized in the right lateral recumbent position. A 3.5-Fr micromanometer-tipped catheter was placed in the RV to determine the hemodynamic changes. Dobutamine (5.0 and 10 microg.kg(-1).min(-1)) and esmolol (50 and 100 microg.kg(-1).min(-1)) were infused intravenously. Pulsed Doppler (PD) and TDI measurements were performed in the apical four-chamber view. Compared with baseline, the PD-MPI decreased significantly with the dobutamine infusion at 5 microg.kg(-1).min(-1) (P < 0.05). Both dobutamine infusions significantly decreased the TDI-MPI (P < 0.01, P < 0.05). Esmolol increased the PD- and TDI-MPI but not significantly. Dobutamine significantly increased the Sa velocity (both P < 0.001), whereas esmolol had no effect. The Sa velocity was strongly correlated with the peak positive derivative of the RV pressure (+dP/dt; r = 0.93). The negative correlation between the +dP/dt and TDI-MPI (r = -086) was greater that with the PD-MPI (r = -0.54). Stepwise regression analysis showed that the Sa velocity and PD-derived isovolumic contraction time were identified to predict the +dP/dt (r = 0.94, r(2) = 0.89; P < 0.001). We determined that the systolic myocardial velocity and TDI-MPI were strongly correlated with the RV contractility. These results suggest that the TDI-derived systolic myocardial velocity and MPI predict RV systolic function.
authors.affiliation: Department of Small Animal Internal Medicine, School of Veterinary Medicine, Kitasato University, 23-35-1 Higashi, Towada, Aomori 034-8628, Japan. hori@vmas.kitasato-u.ac.jp
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Hori
authors.forename: Takuto
authors.initials: T
authors.lastname: Kano
authors.forename: Fumio
authors.initials: F
authors.lastname: Hoshi
authors.forename: Sei-ichi
authors.initials: S
authors.lastname: Higuchi
mesh_terms: D000818:Animals; D004285:Dogs; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology*; D013599:Systole / Q000502:physiology*; D014463:Ultrasonography; D016278:Ventricular Function, Right / Q000502:physiology*