How to read ECG: Mnemonic for ECG

How to read ECG: Mnemonic for ECG

Table of Contents(toc)

Introduction

RRAHI

R= Rhythm

R= Rate

A= Axis

H= Hypertrophy

I= Ischemia

How to calculate heart rate in ECG in regular rhythm ECG

To calculate rate in ECG use the following technique:

1. Take any two R waves
2. Count number of BIG boxes between them
3. Divide 300 by that nymber
4. The result is the heart rate

Alternatively you can use following formula:

1. Take any two R waves
2. Count number of SMALL boxed between them
3. Divide 1500 by that nymber
4. The result is the heart rate

How to calculate heart rate in ECG in irregular rhythm ECG

For irregular rhythm you need to take account of 30 seconds of rhythm strip ECG to calculate rate.

For that use the following technique:

1. Take any 10 big boxes in the rhythm strip
2. 
   

How to check Rhythm of an ECG?

Sinus Rhythm and other rhythm

How to check Axis of an ECG?

Axis means the direction in which the current is flowing in our heart. 

Normally it should start from right atrium and should end on left ventricle and should happen 60-100 times every minute.

How to see Myocardial ischemia in ECG?

There are three things we could look in ECG to delare ischemia.

1. ST elevation and depression
2. T wave inverssion and changes
3. Q waves

Examples are shown in images.

How to see hypertrophy in ECG?

Hypertrohy will cause increase in amplitude in the ECG.

The left ventricular hypertrophy is of special interest to use  due to its high prevalence. 

It is measured by using following method.