First Look at the ECG Flashcards
Learn how to read an ECG
What is the P wave caused by?
Atrial depolarisation
What is the QRS complex caused by?
Ventricular depolarisation
What is the T wave caused by?
Ventricular repolarisation
What is the PR interval?
It is the time from atrial depolarisation to ventricular depolarisation
What does the QRS Complex symbolise?
The time for the WHOLE of the ventricle to depolarise
What is the QT interval?
Time spent while the ventricles are depolarised
Why can you not see atrial depolarisation?
It coincides with ventricular depolarisation. the ventricular depolarisation involves much more tissue depolarising much faster and so swamps any signal from atrial repolarisation
Name the 2 types of limb leads and the examples of each of them
Standard Limb Leads - SLL I, SLL II, SLL III
Augmented Limb Leads - aVR, aVL, aVF
What extra information do the augmented limb leads provide?
Gives 3 other perspectives on events in the heart due to recording from one limb lead with respect to the other two combined
What information do the precordial (chest) leads (V1-V6) provide?
Are all arranged at the front of the heart and therefore look at the same events but in the horizontal (transverse) plane
What can be found at the bottom row of an ECG reading?
The rhythm strip
What is the rhythm strip used for?
It is used to measure heart rate. Count number of R waves in 30 large squares (6 secs) and multiply by ten.
Below 60bpm - Bradycardia
Above 100beats per minute - Tachycardia
What else can the rhythm strip illustrate?
Whether or not each QRS complex is preceded by a P wave
Whether the PR interval is too short (<0.12 sec) or too long (>0.2 sec)
Whether the QRS complex is too wide (>0.12sec) or not
Whether or not QT interval is too long (>0.42 secs at 60bpm)
What does STEMI mean?
ST elevated myocardial infarcion
What does NSTEMI mean?
non-ST elevated myocardial infarction
