ECGs Flashcards
LMCA occlusion
Widespread ST depression
ST elevation > 1mm aVR
ST elevation in aVR > V1
Can also be due to post cardiac arrest, severe anaemia/hypoxia, triple vessel disease
LAD occlusion
ST elevation aVR > 1mm
ST elevation often also in V1-3
Widespread ST depression
Can also be severe triple vessel disease
Raised ICP
Giant cerebral T wave inversion in multiple leads
QT prolongation
Bradycardia
Diffuse ST elevation (STEMI mimic)
General rhythm disturbance
Right heart strain pattern
Right axis deviation RBBB S1 Q3 T3 Dominant R wave in V1 T wave inversion V1-4 and III Persistent S wave V6
PE changes
Sinus tachycardia most common 44%
Right ventricular strain - T wave inversion V1-4 and inferior leads 34%
S1 Q3 T3 20%
RBBB associated with increased mortality 18%
RAD 16%
P pulmonale 9%
Persistent S wave V6 8%
Atrial tachycardias 8%
Dominant R wave V1
Non specific ST and T wave changes in 50%
Wolff Parkinson White
Delta waves (look in inferior leads) Short PR interval < 120 QRS prolongation > 110 ST segment and T wave discordant changes Pseudo infarction pattern due to negatively deflected delta waves
Hypertrophic cardiomyopathy
Left ventricular hypertrophy
Deep narrow dagger like Q waves lateral +/- inferior leads (1, aVL, V5-6)
Often non specific ST/T wave abnormalities
Clinical features - presyncope/syncope, palpitations, chest pain, pulmonary congestion
Brugada
Coved ST elevation > 2mm in > 1 of V1-3 followed by negative T wave Must also have one of the following clinical criteria: - documented VF or polymorphic VT - FH sudden death < 45 - syncope - nocturnal agonal respiration - other family members with ECG changes - VT induced
Can be unmasked by fever, hypothermia, ischaemia, hypokalaemia, alcohol, cardiac drugs
Irregular supraventricular tachycardia
Atrial origin, narrow complex
- atrial fibrillation - no p waves, variable rate
- atrial flutter with variable block - no p waves, saw tooth pattern
- multifocal atrial tachycardia - at least 3 distinct p wave morphologies in same lead
Regular supraventricular tachycardia
Sinus tachycardia Atrial tachycardia Atrial flutter with fixed AV block AV nodal re-entrant tachycardia (classical SVT - regular 140-280, narrow complex, buried p waves so appear absent) AV re-entrant tachycardia (WPW)
Regular broad complex tachycardia
VT
SVT with aberrant conduction due to BBB
SVT with aberrant conduction due to WPW
VT vs SVT ECG features (if clinical features/doubt then treat as VT!!)
Absence typical LBBB or RBBB morphology
Extreme axis deviation
Very broad complexes > 160
AV dissociation
Capture beats
Fusion beats
Positive concordance throughout precordial leads
Negative concordance throughout precordial leads
RSR complexes with taller left rabbits ear
Brugada sign
Josephson sign
Irregular broad complex tachycardia
VF Torsdaes de pointes Polymorphic VT AF with WPW AF with BBB
Mobitz I
Wenckebach
Progressive prolongation PR interval culminating in non conducted P wave
P-P ratio remains constant
Mobitz II
Intermittent non conducted P waves with PR interval remaining normal
Inferior STEMI
ST elevation II, III, aVF
Reciprocal depression aVL
40% STEMIs
20% associated 2nd/3rd degree HB
Avoid nitrates, give fluid, preload dependent
May need paced
Right coronary artery lesion
Inferior STEMI STE III > II STE also in V1 ST depression > 1mm aVL ST depression I
- do right sided leads, ST elevation V4R most specific
Posterior STEMI
ST depression V1-3 with upright T waves
Tall broad R waves V1-3
Dominant R wave V2
Do posterior leads - STE can be 0.5mm
What to think if narrow complex tachycardia rate 150
Atrial flutter with 2:1 block (elderly, IHD)
SVT
AV reentry in WPW
Sinus tachycardia
What to look for in syncope
- Too fast - VT, VF, torsades
- Too slow - sinus bradycardia, pauses, heart block (Mobitz II or 3rd degree)
- Pump failure - MI, PE
- Electrical problems - electrolytes (hypo/hyperkalaemia), pacemaker failure
- Syncope syndromes - long QT, short QT, WPW, Brugada, HOCM, ARVD
Digoxin effect (not toxicity)
Down sloping ST depression (reverse tick) Flattened, inverted or biphasic T waves Shortened QTc PR prolongation Prominent U waves
ECG in digoxin toxicity
Can have supra ventricular tachycardia due to increased automaticity or slow ventricular response due to decreased AV conduction or features of both
Most commonly
- frequent PVCs/bigeminy/trigeminy
- sinus bradycardia
- slow AF
- AV block of any type
- VT
Left axis deviation
QRS positive lead I and negative in lead aVF (also in II and III)
Causes LBBB inferior MI LVH Left anterior fasicular block Paced rhythm WPW
Right axis deviation
QRS positive in aVF (also II and III), negative in I
Causes Right ventricular hypertrophy PE COPD Left posterior fasicular block WPW Hyper kalaemia Sodium channel blocker toxicity
Paediatric ECG
Dominant R in V1 (RSR pattern) T wave inversion V1-3 May have right axis deviation Often shorter PR Can have sinus arrhythmia
STEMI mimics
Benign early early repolarisation LVH LBBB Paced rhythm Pericarditis Left ventricular aneurysm Brugada Takatsubo Increased intracranial pressure
Causes of long QTc
Hypokalaemia Hypomagnesaemia Hypocalcaemia Hypothermia Myocardial ischaemia Post ROSC Raised ICP Congenital Drugs - antipsychotics, TCAs, type Ia (procainimide), Ic (flecanide), III (sotalol, amiodarone), citalopram, venlafaxine, quinine, macrolides
Arryhthmogenic right ventricular dysplasia
Autosomal dominant, second most common sudden cardiac death in young people (after HCM), often associated FH
T wave inversion V1-3 without RBBB Epsilon wave QRS widening V1-3 Frequent PVCs Paroxysmal VT with LBBB morphology (right ventricular outflow tract obstruction)
