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

Although Cardiovascular Risk Stratification (CVRS) based on indices derived from electrocardiogram has been deeply studied, many current findings are not being widely used in the clinical practice. We proposed a framework for CVRS on the Heart Rate Turbulence (HRT) domain, because of its concise guidelines and index calculations. An ontology was built according to a set of rules defining clinical, anatomical, and electrophysiological features. Unlike other biomedical ontologies, ours was based on SNOMED-CT, what guaranteed the standardization and interoperability with emerging Electronic Health Records. The HRT ontology consisted of 310 concepts (289 taken from SNOMED-CT, and 19 as a local extension to model the main concepts of the HRT domain). As a case application, a database of 24-h Holter recordings from 27 patients with Congestive Heart Failure was analyzed, in which basic HRT indices from conventional and emergent signal processing procedures were compared, providing a consistence of 86% and 77% between averaged procedure for HRT index calculations and two processing procedures.