The rate is the number of beats the heart makes per minute (bpm).

60-100bpm is normal.

A slow heart rate <60bpm is called

A fast heart rate >100bpm is called

You can calculate both the ventricular and the atrial rate. You only need to calculate the atrial rate if the

60-100bpm is normal.

A slow heart rate <60bpm is called

**bradycardia**A fast heart rate >100bpm is called

**tachycardia**You can calculate both the ventricular and the atrial rate. You only need to calculate the atrial rate if the

**P:QRS ratio is not 1:1.**Otherwise you can assume it is the same as the ventricular rate.## Calculating the rate - regular rhythm

If the rhythm is regular:

Count the number of large squares and divide into 300

OR

Count the number of small squares and divide into 1500.

Count the number of large squares and divide into 300

OR

Count the number of small squares and divide into 1500.

If we have a look at this example we can see that there are 4 large squares between the QRS complexes (or 20 small squares)

So we calculate the rate by doing either:

300 / 4

OR

1500 / 20

Which both equal = 75 beats per minute

So we calculate the rate by doing either:

300 / 4

OR

1500 / 20

Which both equal = 75 beats per minute

## Calculating the rate - irregular rhythm

This is why I look at rhythm first - if I know the rhythm is irregular then I know I can't calculate the rate the way I normally would.

You SHOULD have checked that the ECG trace was 10 seconds long. Once you have done that, count how many QRS complexes there are in the trace.

If it is not 10 seconds long, count how many QRS complexes there are in 5 seconds if you can.

You SHOULD have checked that the ECG trace was 10 seconds long. Once you have done that, count how many QRS complexes there are in the trace.

If it is not 10 seconds long, count how many QRS complexes there are in 5 seconds if you can.

As you can see in this 10 second trace (I checked!) there are

If there are 11 QRS complexes in 10 seconds, in 60 seconds there must be 11 x 6 = 66

Therefore the rate is

**11**QRS complexes.If there are 11 QRS complexes in 10 seconds, in 60 seconds there must be 11 x 6 = 66

Therefore the rate is

**66bpm**.## Rate - abnormalities

There are several reasons as to why a patient may be

Causes

Bradycardia

**bradycardic**or**tachycardic**.Causes

**most likely**to come up in the competency include:Bradycardia

- Atrioventricular block
- Inferior myocardial infarction