Understanding the ECG. Part 3: Arrhythmias

In this third article of the British Journal of Cardiac Nursing’s ECG series, we will examine arrhythmias caused by abnormal impulse generation. The intention is not to explain every possible rhythm disturbance, but rather to review the most common and clinically relevant arrhythmias, and describe how they can be recognised on the ECG. We will also place each arrhythmia in clinical context by briefly discussing why it occurs, and how it is treated. Hopefully this process will illustrate the mechanisms that cause arrhythmias, and deepen the reader’s understanding of the electrical function of the heart. The rhythm disturbances that we will cover in this article are as follows:  Ectopic beats  Atrial fibrillation (AF) and flutter  Supraventricular tachycardia (SVT)  Ventricular tachycardia (VT)  Ventricular fibrillation (VF)