An electrocardiogram (ECG) is a quick bedside investigation that assesses the electrical activity of the heart. It is a non-invasive, cheap technique that provides critical information about heart rate and rhythm, and helps assess for cardiac disease. ECG monitoring is used in many different healthcare settings, including acute care, cardiac care and preoperative assessment.
This article, the second in a three-part series, discusses interpreting an ECG with a particular focus on cardiac ischaemia (restriction of blood supply to the heart). Part 1 covered cardiac electrophysiology, indications for an ECG, monitoring and troubleshooting; part 3 will focus on cardiac rhythm and conduction abnormalities.