AN ALGORITHM FOR COMPLETE ENUMERATION OF THE MECHANISMS OF SUPRAVENTRICULAR TACHYCARDIAS THAT USE MULTIPLE ATRIOVENTRICULAR, AV NODAL, AND OR MAHAIM PATHWAYS/

The EINTHOVEN system is a model-based expert system that interprets th e cardiac rhythm from the electrocardiogram. It simulates the expected behavior of realistic semi-quantitative cardiac models constructed by heuristic rules to generate interpretations that include both text de scriptions and event-by-event causal explanations in the form of ladde r diagrams. The simulation has been limited by an inability to predict all possible behaviors of hearts with more than one reentrant circuit . We now describe an algorithm that overcomes this limitation. Its out put has been validated by an independent possibility-tree analysis. Ti ming and storage measurements are presented for models with up to thre e slow atrioventricular nodal pathways, four atrioventricular pathways , and a single atriofascicular (Mahaim) pathway. This is the first rep ort in the literature of an algorithm that enumerates all possible mec hanisms for reentrant supraventricular tachycardias that use atriovent ricular, atrioventricular nodal, and/or atriofascicular pathways in hu mans.