Clinical Implications of Isopotential Surface Maps

SUMMARY

Body surface isopotential surface maps are related to electrical events within the heart. The conventional electrocardiogram and vectorcardiogram were compared with the total body potential distribution as depicted by isopotential surface maps by using a normal child and a patient with mild right ventricular hypertrophy (secundum atrial defect). During the latter half of QRS the surface maps were different between the normal and abnormal, although the vectorcardiographic curves were similar. Useful clinical information is present on the body surface that is not evident in vectorcardiogram. In some situations the reduction of information to an instantaneous vector may not only miss information but may provide an erroneous interpretation of events most likely occurring within the heart.