see also:

• cardiology
• cardiac arrhythmias
• LITFL ECG library - a must to check out!
  • LITFL killer ECG patterns part 1 - non-ischaemic
  • LITFL killer ECG patterns part 2 - ischaemic
• basics of the ECG
  • ECG - tall T waves
  • ECG - flat T waves
  • ECG - biphasic or inverted T waves
• an approach to the ECG with ST elevation
• ECG Diagnosis of AMI
• the adult patient with chest pain in the ED

• Ventricular fibrillation (VF)
• Torsade de pointes VT
• Atrial fibrillation (AF)
• Atrial flutter
• Broad Complex Tachycardias Mx and DDx
• Narrow Complex Tachycardias Mx and DDx
• idioventricular rhythm - complete heart block / atrial standstill
• AV block
• premature ventricular ectopic contractions (PVCs):
  • bigeminy
  • trigeminy
  • couplets
• sinus rhythm

• RBBB
• LBBB
• paced beats

• see also Fascicular blocks

• ECG criteria:
  • LAD of -45 to -90deg
  • small q wave 1-4mm in lead I
  • small r wave 1-4mm in lead III
  • normal QRS provided RBBB absent
• aetiology:
  • IHD
  • chronic LVF
  • cardiomyopathy
  • Chaga's disease
  • children with endocardial cushion defect or tricuspid atresia

• uncommon as is short, thick with dual blood supply thus avoid making Dx
• ECG criteria (inaccurate though!):
  • RAD
  • small r wave (<5mm) lead I & small q wave in leads III, aVF
  • normal QRS duration
  • exclude RVH and cor pulmonale

• see ECG Diagnosis of AMI

• reversed tick: ST depression & T inv. in V5-6
• toxic effects:
  • any arrythmia esp. ventricular ectopy, nodal bradycardia
  • NOT rapid AF

• sinus tachycardia
• wide QRS
• prolonged QTc
• VT/VF

• digoxin
• beta blockers
• calcium channel blockers
• lithium (sinus arrest rather than AV block)

• V-W class Ia drugs
• V-W class III drugs
• antipsychotic overdoses
• see prolonged QTc

• flecainide
• moricizine
• phenytoin (but not lignocaine which has no effect on either)
• propranolol

• hyperkalaemia
  • ⇒ tall tented T waves, widening QRS, loss of P wave, etc and eventually sinusoidal appearance, VF or asystole
• hypokalaemia
  • ⇒ ST depression, T wave flattening, prominent U wave creating a prolonged QTc effect, torsade de pointes VT
  • ie. similar ECG effects as has lithium toxicity, although lithium toxicity is also characterised by sinus node dysfunction causing bradycardia, sinus arrest with junctional escape rhythm or asystole, and unlike hypokalaemia, ventricular arrhthmias are rare.
• hypercalcaemia
  • ⇒ shortened QTc
• hypocalcaemia
  • ⇒ prolonged QTc, torsade de pointes VT

• see also pericarditis for the classic four stages of ECG changes
• NB. tachycardia may be the only ECG finding if ST elevation has resolved & T waves remain normal

• see benign early repolarisation
• a cause of ST elevation in V1-4

• see left ventricular hypertrophy (LVH)
• tall R waves laterally +/- hyperacute T waves or LV strain pattern of ST depression with T inversion
• S waves in V1-2
• left axis deviation (LAD)

• see right ventricular hypertrophy (RVH)
• right axis deviation (RAD)

• left atrial abnormality, eg. prolonged PR
• left ventricular hypertrophy (LVH)
• left axis deviation (LAD)
• intraventricular conduction abnormalities esp. Left Bundle Branch Block (LBBB)
• poor precordial R wave progression
• AF
• ventricular arrhythmias

• left ventricular hypertrophy (LVH)
• left axis deviation (LAD)
• septal Q waves but upright T waves
• diminished or absent R waves in lateral leads

• left axis deviation (LAD)
• low voltage
• AF
• ventricular arrhythmias
• AV block
• complete heart block (sarcoidosis)
• acute coronary syndrome patterns (sarcoidosis)

• Right Bundle Branch Block (RBBB)

• see also pulmonary embolism (PE)
• non-specific right atrial strain patterns but these are often not present
• no significant abnormality in up to 25% of sub-massive PEs
• sinus tachycardia common if acute
• SI, QIII, TinvIII but not sens. and not spec.
• strain pattern V1-3 - symmetrical T wave inversion
• ST depression I or II
• SI, SII and SIII pattern
• Q waves in III & aVF
• Qr in V1
• ST elevation in V1, aVR & III
• RAD
• RBBB
• AF or atrial flutter

• see pre-excitation syndromes including WPW

• shortened PR interval
• delta wave
• dominant R in V1
• wide or narrow complex SVTs