Clinical observations with an orthogonal lead system.

TI IE MERITS of several orthogonal lead systems are being investigated and it is possible that records from one or more of the systems will be incorporated into clinical electrocardiography. Selection of a system for clinical use involves consideration of its accuracy, convenience, and reproducibility of the results it yields. An electrode arrangement termed the "axial" system has recently been described by McFee and Parungao.1 Based on its design data, the accuracy of this systemii appears to be comparable to that of systems proposed by Schmitt and Simonson2 and Frank.3 In addition, the axial system is reported to be relatively insensitive to exact electrode placement. This characteristic would be an important asset to convenience and reproducibility of results. Like other proposed lead systems, the axial system requires clinical evaluation. One step in the necessary evaluation is identification in records obtained with the new system of the counterparts of features of known clinical significance from conventional electrocardiographic leads. Such studies may be expected to define the form in which some findings of established importance in conventional leads are reflected by the new system. They mayi also be expected to identify those items of known significance in the conventional tracing that the new leads do not reflect in easily recognizable form. Finally, such studies may be expected to contribute to definition of the