Abstract 12379: Distal Waveform Patterns in the Fontan Circulation Are Related to Pulmonary, Liver and Cardiac Function

Abstract

Introduction: The lack of a sub-pulmonary ventricle in patients with a Fontan circulation leads to irreversible circulatory decline. Our group has determined that single-site waveform analysis correlates to clinical features of Fontan patients. The goal of this study was to determine if multi-site waveform analysis contributes to detecting early cardiovascular decline. Methods: Patients with a Fontan circulation that underwent cardiac MRI were included in this retrospective study. Hemodynamic flow curves were measured in the ascending aorta (AAo N=94), superior vena cava (SVC N=82), inferior vena cava (IVC N=91) and left pulmonary artery (LPA N=85). Flow curves were interpolated to equal temporal phases and were used to create three data matrices of proximal and distal waveforms. Principal component analysis (PCA), a data transformation method used to obtain a wieldy number of ranked components (the PCs) representing the variance of the input data, was performed on each matrix. PCs were correlated to clinical measures of current patient status. Results: PCs that accounted for more than 20% of the variance in a data matrix are reported (Pearson’s r, p ) in Table 1. Conclusions: These results indicate that increased liver enzyme levels, with a possible link to Fontan associated liver disease, are related to increased diastolic SVC flow and increased volume in the SVC and IVC throughout the cardiac cycle. An increased diastolic SVC flow profile relates to worsening pulmonary function and oxygen consumption during exercise. A decreased ventricular-vascular coupling ratio is related to increased IVC volume and low oxygen saturations may be indicative of increased LPA volume. Little variations were apparent in the AAo waveforms, suggesting cardiovascular decline may appear distally prior to proximal presentation. We have, for the first time, evaluated multi-site flow patterns and correlated them to functional status in one of the largest Fontan patient cohorts to date.