Twisted Leads: The Footprints of Malpositioned Electrocardiographic Leads

Abstract

Malposition of electrocardiograph (ECG) leads is poorly recognised even by cardiologists who report tracings. When ECG tracings are regularly performed by doctors, nurses or technicians, lead malposition is very uncommon particularly if the operator can also interpret the findings. However, a significant proportion of 12-lead ECG tracings are today performed in a doctor's surgery or by private pathology services, often in haste without sufficient attention to correct lead positioning. As a result, a variety of malposition combinations occur, which in turn may confuse the interpreter of the ECG tracing, leading to incorrect diagnoses. To investigate various combinations of ECG lead malposition and determine if characteristic findings can be summarised into identifiable footprints. In 10 normal subjects, 12-lead ECGs were performed with normal lead positioning as well as six limb lead malpositions and reversal of chest leads. In all subjects, there was consistency in the ECGs performed allowing the creation of five characteristic and easily identifiable footprints. A summary of the footprints of ECG lead malposition should be readily available for those who perform ECGs, those who interpret the tracings and those responsible for clinical care.