ECG revision Flashcards
What leads look at the right ventricle?
Leads avR, V1, V2 and V3
What leads look at the inferior wall of the heart?
avF, II and III
What leads look at the left wall of the heart?
avL, I, V5 and V6
What leads look at the anterior and septum?
V1-V4 (V1-2 = septum and V3-4 = anterior heart)
How do you calculate rate?
- 300/No. boxes between two R waves.
- Or number of R waves in rhythm strip x 6
T wave inversion is normal in what leads?
V1, V2 and III
Where do you NOT see Q waves?
In V1, V2 and V3
How will right and left axis deviation appear?
Right axis deviation - Lead III is most positive and lead I is negative
Left axis deviation - Lead I is most positive and leads II and III are negative
Left two the right one
How does 1st degree heart block appear?
- Prolongation of PR interval (move than 5 small squares = 0.2s)
How does 2nd degree heart block appear?
Morbitz type 1 - Progressive prolongation of PR interval until an eventual full block.
Morbitz type 2- Pattern of 2/3 conducted P waves followed by complete block.
How does 3rd degree heart block appear?
- No electrical communication between atria and ventricles.
What is meant by progression and what does poor progression suggest?
- R wave will get bigger from V1 to V6 and the S wave will get smaller from V1 to V6. Poor progression can suggest previous MI
What does ST elevation/depression indicate?
ST elevation suggests infarction whereas depression indicates ischaemia.
What are the septal ECG leads?
V1 and V2
Name and describe different P wave morphologies
P mitrale - Bifid P waves, associated with left atrial hypertrophy.
P Pulmonale - Peaked P waves, associated with right atrial hypertrophy.
P wave inversion
What is PEA?
Pulseless electrical activity. Patient is unconscious, has no central pulse but has electrical activity on the ECG.
Describe the appearance of hyper/hypo- kalaemia
Push - pull effect.
Hyperkalaemia - Peaked T waves, P wave flattening and wide QRS.
Hypokalaemia - ST depression, flattened T waves, U waves and QT prolongation
Pathological Q waves are suggestive of what?
A previous MI
What is the most common cause of left bundle branch block?
Conduction abnormalities
What are U waves?
A positive deflection between the T wave and P wave.
What are the causes of U waves?
Athletes, hypokalaemia, hypercalcaemia
What are biphasic T waves?
T wave with two peaks, indicates ischaemia or hypokalaemia
Explain the appearance of SVT on the ECG
- Narrow complex tachycardia, (wide if there is an underlying BBB)
- No normal P waves
- ST depression
Explain the presentation of a RBBB and causes
rSR’ pattern in V1
Slurred S wave in V6.
Causes: RVH, PE, IHD, CHD or normal variant
Explain the presentation of a LBBB and its causes
Appearance - W in V6 and M un V1
Causes - Aortic stenosis, IHD, hyperkalaemia, MI
Explain the management of an SVT
Patients with adverse features (HISS) - Heart failure, ischaemia, shock or syncope should be DC cardioverted
If stable then vagal maneuvers (carotid sinus message or Valsalva maneuver) should be done first then 6mg of adenosine if failed. This will temporarily block conduction through AV node
