Ontology for Heart Rate Turbulence Domain Applying the Conceptual Model of SNOMED-CT

Abstract

Although cardiovascular risk stratification (CVRS) based on ECG-derived indices has been deeply studied, many current findings are not being widely used in the clinical practice. We hypothesized that, in addition to the necessary scientific evidence, also a clear and standardized connection among the current knowledge in the scientific literature, its availability for the cardiologist, and the actual patient data, is necessary for the practical implementation and refinement of these indices. For this purpose, we implemented an standardized framework for CVRS based on ECG-derived indices, focused on the actual knowledge of Heart Rate Turbulence (HRT) indices (with concise guidelines and clear procedures to parameter calculations). An ontology for HRT was built according to a set of logical and relational rules, yielding the class hierarchy model and its corresponding inferred model (Prot¿eg¿e-OWL, 4.1) for completeness. Different from other biomedical ontologies, ours was based on the international standard SNOMED-CT. The model of SNOMEDCT not only considers terminology, but also properties and relationships, what guaranteed the standardization and compatibility with current and emerging Electronic Health Records. Our HRT ontology consisted of 308 concepts (289 from SNOMED-CT, and 19 a local extension to model the main concepts of the HRTdomain). As an application example, a database of 27 instances of patients with HRT from 24-Holter monitoring recordings was considered, with basic HRT indices and also conventional and emergent signal processing calculations. A consistence of 86% and 77% was achieved between averaged procedure for HRT index calculations given in the guidelines and with a filtering procedure.