#CARDIOGRAPH LEARNING SKIN#

Yellow (LA): on the ulnar styloid process of the left arm.

Red (RA): on the ulnar styloid process of the right arm.

Chest electrode positions Limb electrodes You might also be interested in our OSCE Flashcard Collection which contains over 2000 flashcards that cover clinical examination, procedures, communication skills and data interpretation.

V6:left mid-axillary line at the same horizontal level as V4 and V5.

V5:left anterior axillary line at the same horizontal level as V4.

V4:5th intercostal space in the midclavicular line.

V3:midway between the V2 and V4 electrodes.

V2:4th intercostal space at the left sternal edge.

V1:4th intercostal space at the right sternal edge.

The electrodes used to generate a 12 lead ECG are described below. lead I is calculated using data from the electrodes on both the right and left arm). The data gathered from these electrodes allows the 12 leads of the ECG to be calculated (e.g. Only 10 physical electrodes are attached to the patient, to generate the 12 leads.

#CARDIOGRAPH LEARNING SKIN#

It is important to understand the difference between an ECG electrode and an ECG lead.Īn ECG electrode is a conductive pad that is attached to the skin to record electrical activity.Īn ECG lead is a graphical representation of the heart’s electrical activity which is calculated by analysing data from several ECG electrodes.Ī 12-lead ECG records 12 leads, producing 12 separate graphs on a piece of ECG paper. Each large square represents 0.2 seconds.Each small square represents 0.04 seconds.The paper used to record ECGs is standardised across most hospitals and has the following characteristics: It represents the time taken for the ventricles to depolarise and then repolarise. The QT interval begins at the start of the QRS complex and finishes at the end of the T wave. It represents the time between two QRS complexes.

The RR interval begins at the peak of one R wave and ends at the peak of the next R wave. It appears as a small wave after the QRS complex. The T wave represents ventricular repolarisation. The ST segment is an isoelectric line that represents the time between depolarisation and repolarisation of the ventricles (i.e. The ST segment starts at the end of the S wave and ends at the beginning of the T wave. It appears as three closely related waves on the ECG (the Q, R and S wave). The QRS complex represents depolarisation of the ventricles. It represents the time taken for electrical activity to move between the atria and the ventricles. The PR interval begins at the star t of the P wave and ends at the beginning of the Q wave. In healthy individuals, there should be a P wave preceding each QRS complex. You may also be interested in our ECG flashcard deck which can be purchased as part of our collection of 2000+ OSCE flashcards.

Cardiograph learning