ECG Flashcards
How should you look through an ECG?
- Rate
- Rhythm
- Axis deviation
- P-waves
- PR interval (AV/heart blocks)
- Q-wave
- QRS
- ST segment
- T-waves
What can cause a regularly irregular rhythm?
- 2nd degree AV/Heart block – Mobitz type 2
What can cause an irregularly irregular rhythm?
- AF
What shows left axis deviation and what does it indicate?
Left is Leaving
I = +ve
II, III, aVF = -ve
LVH
What shows right axis deviation and what does it indicate?
Right is Reaching
I = -ve
II, III, aVF = +ve
RVH
What is P-pulmonale and what does it indicate?
Peaked P-wave (>2 small squares high)
- Right atrial enlargement
What is P-mitrale and what does it indicate?
Bifid ‘M’ P-wave
- Left Atrial enlargement
How long normally is the P-R interval?
3-5 small squares (0.12-0.2s)
What is 1st degree AV/heart block?
PR interval is prolonged
What is 2nd degree AV/heart block Mobitz I?
Ever increasing PR interval until a QRS is dropped
What is 2nd degree AV/heart block Mobitz II?
QRS complexes dropped for no reason
What is 3rd degree AV/heart block?
No relationship between P-waves and QRS complexes
What does a short PR interval indicate?
William Parkinson White Syndrome
What does a depressed PR interval indicate
Pericarditis
What is a pathological Q-wave and what does it indicate?
- > 1 small squares wide
- > 2 small squares deep
- > 25% QRS complex
- Seen in leads V1-3
Old MI
What is the normal width of a QRS complex?
<3 small squares
What does a wide QRS complex indicate?
- Ventricular arrhythmias
- BBB
What causes a ST-segment elevation?
- STEMI
- Pericarditis
What causes a ST-segment depression?
- NSTEMI
- Ischaemia (stable and unstable angina)
- Digoxin toxicity
Where are T-waves normally inverted?
- aVR
- V1
- Sometimes in leads 3, V2 and V3
What does T-wave inversion indicate?
- Ischaemia
- BBB
- Ventricular hypertrophy
What to tall T-waves indicate?
Hyperkalaemia
What do flat T-waves indicate?
Hypokalaemia
What is a LBBB?
WilliaM
- V1 = W
- V6 = M
What is a RBBB?
MarroW
- V1 = M (RSR)
- V6 = W
What indicates RVH?
- Dominant R wave in V1
- Dominant S wave in V6
- R in V1 more than 7 mm (7 small squares)
- Right axis deviation
What indicates LVH?
- R in V5/V6 + S in V1 > 35mm (35 small squares) (easiest one to spot, just combine the length of the R and S wave and see if they are > 35 mm)
- Inverted T wave in leads 1, aVL, V5 and V6 (left-sided leads ventrical strain)
- Left axis deviation
