Coupled waveform patterns in the arterial and venous fontan circulation are related to parameters of pulmonary, lymphatic and cardiac function

The lack of a sub-pulmonary ventricle in patients with a Fontan circulation contributes to circulatory decline, largely related to increased central venous pressure. Our group has determined that single-site waveform analysis correlates with clinical features of Fontan patients. The goal of this study was to determine if multi-site waveform analysis yielded additional associations with functional status or cardiac performance. Patients with a Fontan circulation (N = 95) that underwent free-breathing cardiac MRI were included in this study. Volumetric flow rate curves were sampled in the ascending aorta, superior vena cava, inferior vena cava and left pulmonary artery. Flow curves were interpolated to equal temporal phases and were then used to create three data matrices of arterial and venous waveforms. Principal component analysis was performed on each matrix and principal components that accounted for >10% variance were correlated to traditional clinical indices. Results indicate correlation of inferior and superior vena cava waveform patterns to parameters of pulmonary (RV/TLC %, lowest SaO₂%), lymphatic (cystatin-c, BUN, alkaline phosphatase) and to ventricular function (CI, EF, EDVi, ESVi and VVCR). This study demonstrates that coupled waveform analysis of arterial and venous vessels relays additional information about Fontan patient status.