RESUMO
PURPOSE: We studied the implementation of a patient-specific torso model created without the use of magnetic resonance imaging in the inverse problem of electrocardiology. METHOD: Three types of inhomogeneous numerical torso models were created, with different degrees of adjustment of the outer surface to patients, whereas the heart and lung models remained unchanged. The torso models were used in the inverse localization of small areas with repolarization changes from simulated difference integral QRST maps. The localization error (LE) was evaluated as the distance between the centers of the modeled and the inversely found area with repolarization changes. RESULTS: The mean LE was 1.88 cm with the standard torso model. After adapting the torso shape, the mean LE was 1.83 cm, whereas after adapting both, the shape and electrode positions, the mean LE was 1.02 cm. CONCLUSION: If torso imaging is not available, a torso model with adapted shape and electrode positions gives only slightly less accurate results.
Assuntos
Potenciais de Ação/fisiologia , Algoritmos , Mapeamento Potencial de Superfície Corporal/métodos , Sistema de Condução Cardíaco/fisiologia , Modelos Cardiovasculares , Tronco/fisiologia , Simulação por Computador , Feminino , Humanos , Masculino , Adulto JovemRESUMO
BACKGROUND: The purpose of this study was to observe the influence of variety in individual torso geometries on the results of inverse solution to 2 dipoles. METHODS: The inverse solution to 2 dipoles was computed from the measured data on 8 patients using either standard torso with various shapes and sizes of the heart and lungs in it or using various outer torso geometries with the same inhomogeneities. The vertical position of the heart relative to the fourth intercostal level was kept constant in all models. The results were compared with the reference solution computed in standard torso. RESULTS: The inverse solution was influenced in 4 of 8 cases by changes of torso geometry and only in 1 of 8 cases by changes of internal inhomogeneities. CONCLUSIONS: The use of individual torso geometry with the knowledge of the true heart position is very important for correct inverse results.