Monitoring of Myocardial Involvement in ARVC | 111 Deformation characteristics of patients with ventricular arrhythmia The 6 patients who experienced sustained VA during follow-up all showed abnormal RV deformation patterns at first evaluation. In the basal segment of the RV free wall, 4 patients showed a type II pattern and 2 patients a type III pattern. During follow-up, all of them progressed to a type III pattern. The small size of this subgroup prevents comparative analyses between subjects with and without VA during follow-up. Progression of modelled RV tissue properties To illustrate the application of longitudinal monitoring of myocardial disease on a patientspecific level, we first provide two representative case studies of subjects included in the cohort. Patient 1 was a 20-year-old female followed in the outpatient department during 4.3 years (Figure 4A). At first evaluation, RV deformation was already slightly abnormal in the basal segment. During follow-up, the deformation pattern of especially the basal segment and to a lesser extent the mid segment became increasingly abnormal with strongly reduced peak strain. In the Digital Twin, it was estimated that the heterogeneity relied on mostly reduced contractility and only slightly on reduced compliance. Patient 2 was a 36-year-old female who experienced sustained VA 2.9 years after first evaluation (Figure 4B). During the first examination, RV deformation was slightly abnormal in the basal segment, with delayed onset of shortening, slightly reduced peak strain and mild post-systolic shortening. During follow-up, deformation patterns became increasingly abnormal in all RV segments, whereby the basal pattern was most affected. This apex-to-base heterogeneity was expressed in the tissue substrate in the Digital Twin as well. Heterogeneity in estimated RV tissue properties was first observed in the activation delay and later also in contractility and compliance. The increasing heterogeneity of estimated tissue properties within the RV free wall was also evident on a group level in all three age-groups (Figure 5, Supplemental table 2). 6
RkJQdWJsaXNoZXIy MTk4NDMw