Reading an ECG Flashcards
What is a normal heart rate ?
60-100 bpm
Which leads do you look at to assess axis deviation ?
Leads I and II
Which section of a heart wave do you look at to assess axis deviation ?
The QRS complex
What does a left axis deviation look like on ECG ?
QRS positive (pointing up) in lead I
QRS negative (pointing down) in lead II
using the thumb method, the thumb pointing up is the side of the deviation
What does a right axis deviation look like on ECG ?
QRS negative (pointing down) in lead I
QRS positive (pointing up) in lead II
using the thumb method, the thumb pointing up is the side of the deviation
What does Left Vs Right atrial hypertrophy look like?
Left atrial hypertrophy = m shaped P wave = “p mitrale”
Right atrial hypertrophy = pointed p wave = “p pulmonale”
What is a normal QRS duration ?
0.12 secs or less
What is considered a wide QRS duration ?
> 0.12 secs
What could a wide QRS indicate ?
- bundle branch block
- ventricular hypertrophy
- HF
- MI
What morphology does a really tall/large QRS indicate ?
Left ventricular hypertrophy
What does an ST elevation/depression indicate ?
MI
stemi/nstemi
What does an ST elevation look like on ECG ?
ST segment (between QRS and T wave) elevated above baseline
What does an ST depression look like on ECG ?
ST segment (between QRS and T wave) dropped below baseline
What does a small T wave indicate ?
Hypokalaemia
What does a tall/tented T wave indicate ?
Hyperkalaemia
What does an inverted/biphasic T wave indicate ?
Ischaemia or Precious infarct
How long is a normal QT interval ?
<400ms
What are the 3 main signs of Hyperkalaemia on ECG ?
- tall, tented T waves
- wide QRS
- flattened P waves
might see all 3 together, might not
Which leads can you ignore in an ECG ?
aVR
How does pericarditis show on ECG ?
General changes across all leads
Which leads does MI show up on ECG ?
Regional changes to specific leads depending which region of heart is affected = indicates where the MI occurred
Which leads on an ECG do you look at to assess bundle branch block ?
V1 and V6
What does the QRS in Left bundle branch block look like on ECG ?
Broad QRS with…
V1 = W shaped QRS
V6 = M shaped QRS
(the changes are seen at the tip of R)
What does the QRS in Right bundle branch block look like on ECG ?
Broad QRS with…
V1 = M shaped QRS
V6 = W shaped QRS
(the changes are seen at the tip of R)
What ECG findings are suspicious of coronary artery disease ?
- ST elevation / depression
- T wave abnormalities (inversion or tall)
- wide/deep QRS complex
- Left bundle branch block
What are the characteristics of left bundle branch block on ECG ?
- broad QRS (>0.12secs)
- V1=W, V6=M shaped QRS
- deep S wave in V1
- no Q wave in V5/6
