An Integrated and Automated Tool for Quantification of Biomechanics in Fetal and Neonatal Echocardiography

Abstract

AbstractBackgroundQuantifying ventricular biomechanics from fetal and neonatal echocardiograms presents unique and significant challenges. A new analysis workflow has been introduced for simultaneous quantification of flow and mechanics of cardiac function using an integrated set of automated, physics-based, echocardiography analysis methods.MethodsWe used in-house developed analysis algorithms to quantify ventricular biomechanics from four-chamber B-mode and color Doppler routine examination recordings for three hypoplastic left heart (HLHS) patients at 33-weeks’ gestation and first week post-birth along with age-matched controls. Chamber morphology, tissue motion, atrioventricular valve inflow, and hemodynamic flow parameters were measured.ResultsPrenatal cardiac output differed between control (LV:157 ± 139 mL/min, RV:257 ± 218 mL/min) and HLHS subjects (410 ± 128 mL/min). This difference persisted for control (LV:233 ± 74 mL/min, RV:242 ± 140 mL/min) and HLHS subjects (637 ± 298 mL/min) after birth. In utero peak early diastolic annulus velocity, e’, was elevated in HLHS subjects (± :1.88 ± 0.97cm/s) compared to controls (LV:1.23 ± 0.81cm/s, RV:1.19 ± 0.57cm/s). After birth e’ increased in control RVs (1.80 ± 0.73cms) compared to control LVs (1.26 ± 0.50cm/s) and HLHS RVs (1.18 ± 1.12cm/s). Postnatal early filling mitral flow velocity for the control subjects (LV:58.8 ± 17.6 cm/s) and early-filling tricuspid flow of the HLHS subjects (64.8 ± 23.7cm/s) were similar, while the late filling velocity decreased for the control subject LV (33.5 ± 8.1 cm/s) compared to the HLHS subjects (66.9 ± 23.0 cm/s). Importantly, flow energy loss in the fetal HLHS hearts was increased (0.35 ± 0.19 m3/s2) compared to the control subjects (LV:0.09 ± 0.07 m3/s2, RV:0.17 ± 0.12 m3/s2), and further increased postnatally for the HLHS subjects (0.55 ± 0.24 m3/s2) compared to the control subjects (LV:0.23 ± 0.20 m3/s2, RV:0.09 ± 0.06 m3/s2).ConclusionsWe demonstrate the feasibility of integrated quantitative measurements of fetal and neonatal ventricular hemodynamics and biomechanics using only four-chamber B-mode and color Doppler recordings.