The Normal 12-Lead Ecg

Abstract

The 12-lead ECG provides information about the electrical activity in the heart viewed from 12 different directions and in two different planes. The standard 12 lead ECG consists of 3 bipolar leads (leads 1, 11 and 111) and 9 unipolar leads (aVR, aVL and aVF, V1-V6) giving information about the inferior wall, lateral left ventricular wall and anterior wall of the heart. It is an invaluable part of the preassessment of the patient prior to surgery and enables the surgeon and anaesthetist to risk assess the patient prior to anaesthetic and surgery.