A new electrode placement method for obtaining 12-lead ECGs

OBJECTIVE: Worldwide, more than 50 million ECGs are carried out annually. Studies show that the standard wrist–ankle placement method may produce poor quality ECGs. Factors including limb movement, tremor, anxiety, cold extremities cause artefacts (distortions of the baseline and ECG waveforms). A problem exists. Physicians face a challenge interpreting poor quality ECGs. Diagnostic delays occur. Patients are subjected to recalls; compassion initiated this study. Torso (modified) leads are favoured as they provide rapid acquisition of better quality ECGs, but cause erroneous electrocardiography. Investigators have not attempted to correct these errors. This study analyses the errors and aims to rectify them. METHODS: Our pilot and other studies indicated that torso electrodes placed close to the heart cause an increase in R wave amplitude >3 mm in inferior leads that results in disappearance of inferior infarcts; a decrease >3 mm in 1 and aVL may cause false lateral infarcts. We hypothesised that finding electrode placements that do not cause alterations in R wave amplitude should correct these problems. Several electrode placements were assessed to obtain ECGs identical with the standard, but with better quality. A total of 1112 patients received standard and new electrode placement recordings. ECG parameters were assessed. A blinded interpreter assisted. RESULTS: Electrodes positioned on the mid-arm and lower abdomen revealed ECGs identical with the standard without artefacts or loss of inferior or appearance of lateral infarcts. CONCLUSIONS: This study proved that the new method is faultless and provides better quality ECGs, no recalls and without risk for misinterpretations. Not having to remove leg garments is convenient and allows more rapid acquisition of ECGs. The forearms are freed for, intravenous, radial access, and ECGs needed during procedures. The findings have implications worldwide for patients, clinicians and technicians, and generate the need to study the method in emergency settings.