Visual Analysis of Heart Reinervation after Transplantation

During heart transplantation complete denervation of allograft occurs. Partial reinnervation may develop after one year or later. It can be detected by different methods i.e., iodine123-meta-iodobenziylguanidine (MIBG) scintigraphy, positron emission tomography (PET), heart rate variability (HRV), etc. We propose an alternative noninvasive method based on visual diagnostics (VD) and supported by a custom developed tool (ComVis), which enables interactive visual analysis of large data sets by exploiting focus and context (simultaneous local and global view), multiple coordinated views and advanced interaction. Measurements of patients with transplanted heart are rare and valuable, therefore they should be analyzed in all details. Different statistical characteristics and time series from ECG and respiration measurements from fifteen patients and twelve healthy controls have been analyzed using the ComVis tool. MIBG scintigraphy imaging was included, as well. Heart to mediastinum ratio (HMR) was used as a measure of the ventricular reinervation. HRV was analyzed to evaluate sinus node reinnervation. HRV was synchronized on well defined expiration moment and analyzed in time-domain. We will describe some new diagnostic results or rules that were deduced from interactive visual analysis and may help in the future investigation of heart reinervation.