ECG Session

• What does the P wave represent?


  Atrial depolarisation
• What does the PR segment represent?


  Delay at AVN
• What does the QRS complex represent?


  Ventricular depolarisation
• What does the T wave represent?


  Ventricular repolarisation
• What does the isoelectric line represent?


  No electrical activity
• What is the systematic approach to interpreting an ECG?

  Pt background

  Rate

  Rhythm

  P wave

  PR interval

  QRS

  QT

  Axis

  ST

  T wave
• ECG strips run at 25 mm/s
• What is normal HR?


  60-100 bpm
• What is bradycardia?


  HR < 60 bpm
• What is tachycardia?


  HR > 100 bpm
• How can you calculate rate on an ECG?


  QRS complexes x 6
• What is important to look at regarding rhythm?

  Are the QRS complexes regular? (consistent R-R interval)

  Is it irregular?

  If so, is it regularly irregular or irregularly irregular
• What is important to look at regarding P waves?


  Are they there?

  Is it before every QRS?

  Is there 1 P wave to every QRS?
• What is important to look at regarding PR interval?


  Is it the normal length?

  Does it stay the same length?
• What is the normal length for PR interval?


  120-200 ms (3-5 small squares)
• What is the normal duration of QRS complex?


  < 120 ms (3 small squares)
• What does a broad QRS indicate?


  Bundle branch block or a ventricular ectopic
• What is QTc?


  QT interval corrected for rate
• What are the normal QTc intervals?


  Men ≤ 450ms

  Women ≤ 470ms
• How can you identify left axis deviation?


  Lead I is positive

  Lead II is negative

  Leads are Leaving one another

  
• How can you identify right axis deviation?


  Lead I is negative

  Lead II is positive

  Leads are Reaching one another

  
• The ST segment should be on the isoelectric line.

  It can be elevated, depressed or saddle shaped (in pericarditis)

  
• Cannot comment on the ST segment in bundle branch block.
• What does this image show?

  ST elevation

  
• What does this image show?

  ST depression

  
• What is important to look at regarding the T wave?


  Should be upright in all leads apart from III, V1 & aVR
• What does a negative T wave indicate?


  Ischaemia
• Fill in the blanks

  A) Lateral

  B) Inferior

  C) Inferior

  D) Inferior

  E) Lateral

  F) Septal

  G) Septal

  H) Anterior

  I) Anterior

  J) Lateral

  K) Lateral

  
• When does a STEMI occur?


  Complete coronary artery occlusion

  ST segment will rise above isoelectric line
• Other than ST elevation, what can also indicate a STEMI?


  A new left BBB
• What is an NSTEMI caused by?


  Partial coronary artery occlusion
• What ECG changes may be present in an NSTEMI?


  ECG may be normal

  T wave inversion

  ST segment depression
• How does a posterior MI look in ECG?


  Horizontal ST depression in V1-V3 (reciprocal changes)

  
• Other than STEMI, what are the other causes of ST elevation?


  Brugada

  Intra-cerebral haemorrhage

  Pericarditis
• How does pericarditis appear on ECG?


  Widespread concave ST elevation & PR depression

  
• What is shown in the image?

  Pericarditis

  
• What is Brugada?


  Genetic heart disorder - sodium channelopathy -> arrhythmias

  3 types -> most important to know is Type 1

  Management -> ICD
• What is needed to make a diagnosis of Brugada?


  ECG changes AND 1 of the following...

  • documented VF (ventricular fibrillation) or polymorphic VT (ventricular tachycardia)
  • FHx of SCD at < 45 years old
  • Inducibility of VT with programmed electrical stimulation
  • Syncope
  • Nocturnal agonal respiration
• What are the ECG changes in Type 1 Brugada?


  Coved ST elevation in V1-V3 followed by negative T wave 'Brugada sign'

  
• What is shown in the image?

  Type 1 Brugada syndrome