title: The 12-lead electrocardiogram in exercise testing. A misleading baseline?
abstract: Mason and Likar reported a modified ECG lead system that largely eliminates intraexercise artifact without reportedly altering the configuration of the recorded leads. This system allows continuous monitoring of all 12 leads during and after exercise and has become the standard by which other systems are compared. We have found, however, that important changes may be seen between the baseline exercise ECG using the Mason-Likar modification and a simultaneous standard ECG. While these differences do not apparently affect the interpretation of the test, they may produce or obscure evidence of antecedent infarction on the baseline exercise ECG and thus preclude it from being considered interchangeable with a standard ECG.
mesh_terms: D004562:Electrocardiography / Q000379:methods*; D005080:Exercise Test / Q000379:methods* / Q000592:standards; D006801:Humans