Visualization of the intracavitary blood flow in systemic ventricles of Fontan patients by contrast echocardiography using particle image velocimetry.

Konstantinos Lampropoulos,Els Troost,Joost P Van Melle,Alexander Van De Bruaene,Werner Budts

doi:10.1186/1476-7120-10-5

Konstantinos Lampropoulos, Els Troost + Show 3 more

Open Access

https://doi.org/10.1186/1476-7120-10-5

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Abstract

BackgroundFlow patterns in univentricular hearts may have clinical value. Therefore, it is our objective to asses and characterize vortex flow patterns with Fontan circulation in comparison with healthy controls.MethodsTwenty-three patients (8 Fontan and 15 normal patients) underwent echocardiography with intravenous contrast agent (Sonovue®) administration. Dedicated software was used to perform particle image velocimetry (PIV) and to visualize intracavitary flow in the systemic ventricles of the patients. Vortex parameters including vortex depth, length, width, and sphericity index were measured. Vortex pulsatility parameters including relative strength, vortex relative strength, and vortex pulsation correlation were also measured.ResultsThe data from this study show that it is feasible to perform particle velocimetry in Fontan patients. Vortex length (VL) was significantly lower (0.51 ± 0.09 vs 0.65 ± 0.12, P = 0.010) and vortex width (VW) (0.32 ± 0.06 vs 0.27 ± 0.04, p = 0.014), vortex pulsation correlation (VPC) (0.26 ± 0.25 vs -0.22 ± 0.87, p = 0.05) were significantly higher in Fontan patients. Sphericity index (SI) (1.66 ± 0.48 vs 2.42 ± 0.62, p = 0.005), relative strength (RS) (0.77 ± 0.33 vs 1.90 ± 0.47, p = 0.0001), vortex relative strength (VRS) (0.18 ± 0.13 vs 0.43 ± 0.14, p = 0.0001) were significantly lower in the Fontan patients group.ConclusionsPIV using contrast echocardiography is feasible in Fontan patients. Fontan patients had aberrant flow patterns as compared to normal hearts in terms of position, shape and sphericity of the main vortices. The vortex from the Fontan group was consistently shorter, wider and rounder than in controls. Whether vortex characteristics are related with clinical outcome is subject to further investigation.

Highlights

Particle image velocimetry is a new technique of determining the velocity and the direction of fluid streams by analyzing the change in position of small particles that drift with the fluid
There was no significant difference in age and gender between the controls and Fontan patients groups
Characterization of systemic ventricular vortex flow Images of the resulting flow patterns from a 29-year old male Fontan patient, born with Double inlet left ventricle (DILV), Ventricular septal defect (VSD) and pulmonary atresia are presented in Figure 1 (Additional file 1)

Summary

Introduction

Particle image velocimetry is a new technique of determining the velocity and the direction of fluid streams by analyzing the change in position of small particles that drift with the fluid. With the recent development of echocardiographic technology, it is possible to apply this approach to contrast-enhanced echocardiographic imaging [1,2,3]. The growing knowledge about the structure and function of the ventricle [4] was of high interest to us in the context of ventricular vortex development in the Fontan patients. The demonstration of diastolic vortex formation in normal human hearts and their distortion by valve surgery [6] led to our study objective to what extent blood flow patterns in congenitally abnormal, functionally univentricular hearts of Fontan patients are different from normal ones. Flow patterns in univentricular hearts may have clinical value. It is our objective to asses and characterize vortex flow patterns with Fontan circulation in comparison with healthy controls

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