Pulsed wave tissue Doppler imaging of the left ventricle in foals: Feasibility, inter‐ and intra‐observer variability and wave pattern over the first days of life
Fernanda Timbó D'el Rey Dantas, Gayle Hallowell, Carolina Castagnetti, Giovanni Romito, Laura Menchetti, Aurora Mannini, Aliai Lanci, Jole Mariella, Francesca FrecceroAbstract
Background
Tissue Doppler imaging (TDI) may improve the assessment of myocardial function in neonatal foals.
Objectives
To document the feasibility of left ventricular pulsed wave (PW) TDI, inter‐ and intra‐observer variability and wave pattern over the first 5 days of life.
Study Design
Prospective observational study.
Methods
Transthoracic echocardiography was performed in 25 healthy Standardbred foals within the first 24 h after birth (T1), between 60–84 h (T2), and 108–132 h (T3) after birth using right parasternal short‐axis (R‐LV SAX) and subcostal long‐axis views at the mitral annulus, both at the interventricular septum (SC‐MV IVS) and free wall (SC‐MV FW). Systolic (S 1 , S m ) and diastolic (E 1 , E m , A m ) peak velocities were measured at each site. Intra‐ and inter‐observer variability was assessed using intraclass correlation coefficients (ICC). Longitudinal changes were analysed using Friedman's test with Sidak‐adjusted pairwise comparisons. E m and A m were compared using the paired Wilcoxon test.
Results
Pulsed wave tissue Doppler imaging was feasible in all foals. S 1 and E 1 were frequently indistinguishable. ICCs showed excellent agreement for most variables; measurement variability was low. S m (R‐LV SAX: T1 = 9.3 [8.2–11.0] cm/s; T3 = 12 [11.1–12.7] cm/s; p < 0.01), E m (R‐LV SAX: T1 = 15.8 [14.1–20.1] cm/s; T3 = 22.1 [20.2–25.5] cm/s; p = 0.003; SC‐MV FW: T1 = 16.9 [15.2–20.6] cm/s; T3 = 21.0 [18.1–22.3] cm/s; p = 0.019) and R‐LV SAX E m /A m (T1 = 1.5 [1.3–1.9] cm/s; T3 = 1.9 [1.7–2.6] cm/s; p = 0.003) increased over time. E m was higher than A m in the R‐LV SAX view at all time points.
Main Limitation
Effective sample size varied across analyses.
Conclusions
Pulsed wave tissue Doppler imaging was feasible. S m and E m increased over time, while A m remained stable, indicating early ventricular adaptation to extra‐uterine life. PW TDI may be a useful tool in myocardial function monitoring of neonatal foals.