How ECG monitoring contributes to patient care

An electrocardiograph (ECG) has two main purposes: to record the heart rate and the heart rhythm. An ECG can assist the person who is monitoring the patient in many situations, for example during anaesthesia, help assess emergencies, to monitor post-surgical cases, or if an arrhythmia is suspected. Furthermore, continuous monitoring systems such as telemetry, allow monitoring from a distance, so a patient can be observed without disturbance. Anecdotally, nurses want to use ECGs but are limited by a lack of understanding, frequently worried whether what they are looking at on screen is serious or not. This can distract nurses to the point where the ECG is ignored, or even not attached in the first place. This article aims to make interpretation simpler, help nurses become more confident in using ECGs, and provide a quick and simple guide to help the nurse know when to be concerned and seek advice.

The ECG trace is based on a conduction system within the heart (shown in Figure 1). An electrical impulse is generated within the sinoatrial (SA) node, and this impulse travels across the atria depolarising the myocardium as it goes, and arrives at the atrioventricular (AV) node. The impulse then transmits via the right and left His bundle, and down through the Purkinje fibre network and depolarises the ventricular myocardium. This electrical activity can be recorded on an electrocardiogram. When the conduction system works correctly, it produces a normal or sinus complex, consisting of a P wave, a QRS complex and a T wave (Figure 2).