ECG abnormalities Flashcards
What are the ECG abnormalities in a pulmonary embolism? (3)
- Some normal
- Sinus tacchycardia
- Sometimes: complete/incomplete RBBB
- Rare: “SI QIII TIII” classic sign
What are the ECG abnormalities in a STEMI? (5)
- Equal to and greater than 1mm ST elevation in at least 2 adjacent limb leads
- Or equal to and greater than 2mm ST elevation in at least 2 adjacent praecordial leads
- Left bundle branch block new onset
- Broad QRS complex
- Or equal to and greater than 1mm horizontal ST depression in reciprocal leads
How does an ECG change as an STEMI progresses? (6)
- Normal
- Hyperacute T waves (was rounded bump = peaked)
- ST segment elevation
- ST segments return to baseline
- T wave inversion
- Pathological Q waves
What are the ECG abnormalities in a posterior MI? (2)
- Reciprocal anterior ST depression
- Dominant R wave (reciprocal Q wave) in V1
What are the ECG abnormalities in atrial fibrillation? (2)
- No P waves
- Irregularity of QRS complex from beat to beat
What explains the ECG abnormalities in atrial fibrillation?
Rhythm irregular as no coordinated atria activity
In an anterior MI where would ST elevation be seen? (2)
- Mainly in anteroseptal leads (V1-V3)
- In some anterolateral leads (V4-V5)
What part of the heart is damaged in an anterior MI? (2)
- Anterior heart
- Left anterior descending artery
What part of the heart is damaged in a lateral MI? (2)
- Lateral aspect of heart
- Left circumflex artery
In a lateral MI where would ST elevation be seen? (2)
- Anterolateral leads (V4-V6)
- Lateral limb leads: Lead I and Lead avL
In an inferior MI where would ST elevation be seen? (3)
(Inferior leads)
- Lead II
- Lead III
- Lead avF
What part of the heart is damaged in a inferior MI? (2)
- Posterior inferior wall
- Right coronary artery
What kind of arrhythmia is common in an inferior MI? (2)
- Severe bradycardia
- Mobitiz type 1 second degree heart block
Why is bradycardia a common complication of an inferior MI?
In 90% of patients right coronary artery supplies SAN and AVN
What are the ECG abnormalities in first degree AV block? (5)
- Rate variable
- Regular narrow QRS
- P waves present
- P:QRS 1:1
- PR interval more than 200ms
What are the ECG changes in sinus arrhythmia?
- RR interval shortens in inspiration
- RR interval lengthens in expiration
What ECG changes are normal with ethnic variation? (3)
- Left ventricular hypertrophy
- T wave inversion
- ST elevation
What are the ECG changes seen in acute MI? (7)
- Normal
- Hyperacute T waves
- ST segment elevation
- ST segment depression in recipricoal leads
- Improvement in ST segments with reperfusion
- T wave inversion
- Pathological Q waves
What are ECG indications of left ventricular hypertrophy?
- S wave in V1/V2
- R wave in V5/V6 more than equal to 35mm
What in an ECG indicates a greater danger of congestive cardiac failure?
Downwards sloping ST segment
What ECG sign suggests total occlusion of one of the main 3 arteries?
ST segment elevation
When are Q waves pathological? (2)
- Greater than 1mm
- More than 25% height of R wave
What do pathological Q waves indicate?
Transmural myocardial infarction
How does a transmural myocardial infarction appear on a CT scan? (2)
- Brightness : endocardial to epicardial surface of left ventricle
- Oedema = enhancement
What should be noticed on an ECG to diagnose an arythmia? (5)
- QRS rate
- QRS complexes regular?
- QRS broad/narrow?
- P waves?
- P:QRS relation?
What are the ECG changes for atrial fibrillation? (4)
- No P waves in every lead
- Irregularly irregular QRS complexes
- Normal QRS shape (AV node conduction normal)
- Normal T waves
What are the ECG changes in 3rd degree heart block?
P waves completely dissociated from QRS complex
What are the ECG changes in pulmonary embolism? (6)
- Most common: just tachycardia
- Rightward axis deviation
- Incomplete RBBB
- Lead I: very negative
- Lead III: Q wave
- Simulatenous T wave inversion in inferior and anteroseptal leads
What is the “classic” PE ECG finding that’s actually very rate?
S1Q3T3
What is a left bundle branch block?
The left ventricle is not directly activated by impulses travelling through the left bundle branch
What is the mnuemonic for LBBB?
WiLLiaM
‘W’ in lead V1 and an ‘M’ wave in lead V6
What is the mnuemonic for RBBB?
MaRRoW
‘M’ wave in lead V1 and a ‘W’ wave in lead V6
ECG abnormalities in pericarditus (3)
- Widespread saddle shaped ST elevation
- Concave ST (a little elevated)
- PR interval depression
ECG changes in NSTEMI/unstable angina? (3)
- ST depressions
- T-wave inversion
- No pathological Q waves
Atrial flutter (2)
- Regular number of P waves in between QRS complex
- But too many P waves between QRS complexes
Supraventricular tacchycardia (2)
(electrical impulse recycling around AV node)
- Narrow QRS complexes
- Tacchycardia
Ventricular tacchycardia
- Amplitude of QRS is the same
- Big hill looking QRS
- RS interval: more than 100ms
- Could have pulse
Ventricular fibriilliation (3)
- No pulse
- Small wiggly line
- Very irregular rhythm with indiscernible P waves or QRS complexes on ECG
Sinus bradycardia
Slow HR with regular P waveswaves
Mobitiz type 1 second degree (2)
- PR interval slowly increases
- Until dropped QRS complex (beat)
Mobitiz type 2 second degree (2)
- Regular PR interval
- Random dropped beats
Hyperkalaemia (kidney failure/rhamdomyolsis) and eventual change? (4)
- Tall tented T waves
- Wide QRS
- P waves flattening
Eventually: Prolonged PR interval and P waves disappear
Hypokalaemia (diarrhoea,DI,furosemide) (4)
- ST segment depression
- Inverted T waves
- Large U waves
- Prolonged PR
