MODEL-BASED RHYTHM ANALYSIS OF THE ECG - EVALUATION OF A PROTOTYPE IMPLEMENTATION

Current computer algorithms that interpret cardiac rhythms based solel y on the surface electrocardiogram are limited, yet offer many benefit s to health care. To address the limitations, novel computer algorithm s for the automatic diagnosis of complex cardiac rhythms based solely on the surface electrocardiogram are presented. Using the hypothesize- and-test paradigm, a physiologic model of the cardiac conduction syste m and production rule-based knowledge are combined to reason about the time- and space-varying characteristics of complex heart rhythms. In addition, an evaluation of a prototype implementation of the algorithm s is presented. A database of the time of onset, width, and shape clas sifications of each P wave, QRS complex, and T wave from 59 electrocar diographic strips was developed from an introductory textbook by hand- annotation using calipers. The database was not used in the developmen t of the prototype. The prototype's diagnoses were reviewed by a clini cal cardiac electrophysiologist who was not involved in the developmen t process. Pair-wise comparisons among the prototype, textbook, and ca rdiac electrophysiologist, assuming either the textbook or electrophys iologist as the gold standard, were performed. The specific comparison s performed were prototype versus textbook, electrophysiologist versus textbook, prototype versus electrophysiologist, and textbook versus e lectrophysiologist. For all diagnostic categories, sensitivities of 88 .0%, 97.2%, 78.6%, and 82.1%, respectively, and specificities of 99.2% , 98.5%, 99.7%, and 99.8%, respectively, were attained. When accountin g for design and implementation limitations of the prototype, sensitiv ities of 93.0%, 98.5%, 89.1%, and 92.7%, respectively, and specificiti es of 99.4%, 99.2%, 99.6%, and 99.8%, respectively, were attained. The results indicate that these algorithms offer clinical advantages over currently available arrhythmia analysis systems.