Cardiology Teaching Package
A Beginners Guide to Normal Heart Function, Sinus Rhythm & Common Cardiac Arrhythmias
Atrial Fibrillation and Flutter
Review of Sinus Rhythm
Whatever rhythm you are evaluating, it is essential that you have a basic understanding of Sinus Rhythm. Sinus Rhythm tells you that the conduction system in the heart - SA node, AV node, Bundle of His, bundle branches and Purkinje fibres - is working normally.
The sole task of the heart is to pump blood and oxygen around the body and into the coronary circulation. This is done in the most efficient manner if the conduction system is working normally. If the heart is no longer in sinus rhythm, it means that the supply lines for blood and oxygen have become undermined and that the patient may well suffer as a result.
Before we begin discussing Atrial Fibrillation (AF), the picture below gives you a reminder of the conduction system and how sinus rhythm appears on a rhythm strip.
Image: Normal Sinus Rhythm
- The P wave represents atrial depolarisation and contraction
- The QRS complex represents ventricular depolarisation
- The T wave represents repolarisation.
