Congratulations, you have taken the biggest step to ‘owning’ the ecg.
This one investigation, perhaps the most common investigation done today, strikes fear into the hearts of many.
The ECG in 20 Seconds System, will make you an expert. Below are a set of videos that take you over the ECG System, developed by Dr Kas.
Within 2 hours you will have the basics of the system. You can then build on this with more specialised videos.
Let's Now Look at The Breakdown of the Parts of the ECG in 20 Seconds System.
1 Rate, Rhythm and P-QRS
2 The QRS Complex
The Basis Way to Read an ECG- The ECG in 20 Seconds Method.
Remember we are trying to pick up the things that will kill the patient. Use this as a template to which you will add notes. We will be adding to it as we go.
STEP 1 THE STORY
Is this a story of arrhythmia or ischaemia? Depending on the story you will be looking for different thongs in the ECG. For example, if the story is of palpitations you will be searching for conditions such as WPW, VT etc.
STEP 2 THE RATE
Given that a normal ECG is produced in 10 seconds, simply count the number of complexes along the rhythm strip(usually lead II) and multiply by 6. This gives heart rate per minute.
STEP 3 IS IT SINUS AND THE P WAVE
Is there a P wave?
For sinus rhythm the P wave must be upright in II and inverted in aVR.
Look at lead I. If the P wave is inverted, look for limb lead reversal and repeat the ECG.
Is there a P wave before each ECG?
If not look for a MOBITZ Block.
Look for the P-P interval. The P-P interval must be regular, if not, it is a premature atrial contraction.
If the P-P interval is regular, then look for the PR interval.
- If the PR interval lengthens then a QRS is dropped it is Wenckebach
- If the PR interval is regular and a QRS is dropped regularly it is a Mobitz II
- If the PR interval is of random lengths it is a Complete Heart Block
STEP 4 THE QRS
1 Is it Tall or small?
- Here we are looking for left ventricular hypertrophy(LVH)
- If the R wave in V1 + the S wave in V5/6 is > 35mm = LVH
- Specifically look for the pathological waves of HOCM
2 Is it wide or narrow?
Wide indicates a Bundle Branch Block, Hyper K, Na channel Block, VT
3 Does it have abnormal morphology?
Here we are looking for the delta wave of Wolff Parkinson White Syndrome.
4 Are there Q waves?
5 Are The QRS’s clumped?
If the QRS’s are clumped, go back and look for a Mobitz Block again.
STEP 5 THE ST – T SEGMENT
This is where we look for:
1 Ischaemic Changes
ST elevation and the subtle signs of the ‘QRT’ Sign, the Straight ST segment and the hyperacute T waves.
2 ST depression, whether ischaemic or reciprocal
3 Are the T waves inverted?
STEP 6 THE INTERVALS PR AND QT
Look for a long PR interval as well as a long QT interval
STEP 7 PACING SPIKES
Always look for pacing spikes in all leads.