Gloucestershire Heart Failure Service ECG Interpretation Adrian Strain Heart Failure Specialist Nurse

1. Gloucestershire Heart Failure ServiceECG InterpretationAdrian StrainHeart Failure Specialist Nurse

2. Aims • The normal adult ECG • Barn door MI • Inferior / Lateral / Anterior • Blocks • Iº / IIº / IIIº (CHB) • Bundle Branch Block (Left and Right) • Atrial tachycardia • Atrial fibrillation

4. Normal Adult ECG

5. Normal Sinus Rhythm – the rules! • P before every QRS • PR interval <0.2 seconds (5 baby squares) • QRS after every P wave • QRS <0.12 seconds (3 baby squares) • Regular and identical • Rate 60-100 bpm • <60 bpm – sinus bradycardia • >100 bpm – sinus tachycardia

7. Heart Rate: 300, 150, 100, 75, 60, 50, 43, 37 bpm

8. Heart rate is….?

9. Reporting an ECG • Rhythm • Conduction intervals • Cardiac axis • Description of QRS complexes • Description of ST segments and T waves

10. Reporting an ECG • Rhythm • Conduction intervals • Cardiac axis • Description of QRS complexes • Description of ST segments and T waves

11. ST Elevation - Myocardial Infarction • ST elevation in two or more leads • Must be at least 1mm in limb leads • Must be at least 2mm in chest leads • Thrombolysis • Chest pain! • Present within 12 hours of onset of pain • No contraindication

12. ST depression • >2mm usually indicates ischemia • Common in normal ECG, especially in pregnancy • But: • Non specific not more than 2mm below baseline • It is convex downward or slopes upwards from the S wave

14. Normal ECG

15. The leads • II III and avF - inferior leads • I avL V5 and V6 - lateral leads • V3 and V4 - anterior leads • V1 and V2 - septal leads

16. Normal ECG

17. Antero-Lateral MI

19. InferiorMI

20. Posterior/LateralMI

21. Heart blocks – First Degree AV block • PR interval > 0.2 seconds • Treatment rarely required • Caution when introducing / titrating beta blocker and other rate reducing agents • Regular ECG’s to monitor !!

22. Second Degree AV block • Mobitz type I – Wenckeback • Progressive lengthening of P-R interval • Most patients are asymptomatic • May experience dizziness or syncope • May have chest pain if myocarditis or ischemic • May have history of structural heart disease.

23. Second Degree AV block • Mobitz type II – • Characterised by unexpected nonconducted atrial impulses • PR and R-R intervals between conducted beats are constant. • Commononly caused by MI • Risk of progressing to complete heart block

24. Complete Heart Block • Third Degree – Complete AV block • Complete dissociation between P’s and QRS’s • Often bradycardic!! • Will require pacing

25. Bundle Branch Block - BBB

28. SVT – Supraventricular tachycardia‘palpitations’ • Narrow and fast • Impulse is generated from above the ventricles • Essentially it is an atrial tachycaria

30. Atrial Fibrillation

31. Remember • There is no such thing as slow AF.. • All AF is fast – • The ventricular rate may however be slow. • Rate reducing agents include Beta Blockers, Amioderone, Digoxin and calcium channel blocker

32. LVH with ‘strain’

33. Its your turn…….

34. Number 1

35. Number 1 - Mobitz type I

36. Number 2

37. Number 2 – Anterior MI

38. Number 3

39. No 3: Complete Heart Block

40. Number 4

41. Number 4 - LBBB

42. Number 5

43. Number 5 – First Degree

44. Number 6

45. Number 6 - RBBB

46. LBBB – wide and negative in V1

47. RBBB – wide, positive and R-S-R pattern in V1

48. Number 7

49. No 7: Atrial Fibrillation with fast ventricular response.

50. Summary • Follow the rules • Rhythm • Conduction • Describe QRS complex • Describe ST & T wave • Identify if normal • If abnormal – think why! • Symptomatic? • MI – AF – BBB – heart failure – enlarged heart – etc.