Accessing the rhythm 1

• First thing in accessing the rhythm is whether it is regular or irregular
• And then see the width of the QRS complex
• If the QRS complexes are less than 120 msec (i.e. 3 small squares), the rhythm is supraventricular in origin (i.e. sinus, atrial or junctional)
• If more than 120 msec, the rhythm is ventricular in origin.

• In this ECG, the rhythm is irregular and the QRS complexes are less than 120msec.