Arrhythmia :ECG-Bradycardia_20120909_中區

1. Bradycardia
大林慈濟醫院心臟內科
李易達醫師
101.09.09

2. 竇房節
(SA node)
房室結
(AV
node)
希氏束
(Bundle of
His)
浦金氏纖維
(Purkinje
fiber)

3. Normal sinus rhythm
HR: 87bpm, PR interval: 150ms

4. Normal sinus rhythm
•Heart rate: 60~100bpm
•A P wave before every QRS complex
•Normal P axis (upright in lead II)
•PR interval >0.12 second

5. HR: 61bpm, PR: 128ms
 Ectopic atrial rhythm

6. Rhythm evaluation on ECG
•Rate
–Regularity
•P wave ?
•P wave morphology
•P wave axis
–Normal P wave axis: upright in lead II
•PR interval (P & QRS relationship)
– Normal PR interval: 120~200ms
–Constant

7. Bradycardia
•Bradycardia: heart rate < 60bpm
•May be a normal physiological
phenomenon or result from a cardiac or
non-cardiac disorder
–During sleeping
–Athletes
•Symptoms:
–Dizziness, near syncope, syncope, ischemic
chest pain, and hypoxic seizures

8. Pathological etiologies of bradycardia
•Medication
–B-blocker
–Ca channel blocker
–Digoxin
–Class IA, IC, III
•Myocardial infarction
•Inflammation/infection
–Myocarditis
–Infectivce endocarditis
–Lyme disease
•Metabolic effect
–Electrolytes
–Hypothyroidism
–Hypothermia
•Autoimmune diseases
–SLE
•Surgery
•Degeneration
–Sick sinus syndrome

9. Bradyarrhythmia
•Sinus node dysfunction
–Symptomatic sinus bradycardia
–Sinus pause/sinus arrest
–Sino-atrial exit block
–Tachycardia-bradycardia syndrome
•AV block
•Junctional/ventricular escape rhythm
•Atrial fibrillation with slow ventricular response

10. Marked sinus bradycardia
•May be symptomatic if heart rate < 45bpm
•Usually related to
–Increased vagal tone
–Medication: b-blocker, Ca channel blocker
–Sick sinus syndrome (SA node dysfunction)

11. Marked sinus bradycardia
HR: 42bpm, PR: 184ms

12. Sinus pause/arrest
•Transient cessation of impulse formation
at the sinoatrial node
•A prolonged pause without P activity
•The pause is unrelated to the length of the
P-P cycle

13. Sinus pause/arrest

14. SA exit block
•A transient failure of sinus impulse
conduction to the atrial myocardium
•SA exit block
–1
st
degree SA block
–2
nd
degree SA block
•Type I: group beating, shortened PP interval
•Type II: the pause length was two times of PP
interval
–3
rd
degree SA block: escape rhythm

15. SA exit block

16. 2
nd
degree SA exit block type I
HR: 91bpm, PR:142bpm

17. 2
nd
degree SA exit block type II

18. Tachycardia-bradycardia syndrome
•Common in sick sinus syndrome (sinus
node dysfunction)
•Paroxysmal atrial tachyarrhythmia
followed by sinus bradycardia, sinus
pause or escape rhythm

19. Tachycardia-bradycardia syndrome

20. EPS to evaluate sinus node function
•Sinus node recovery time (SNRT)
–SNRT < 1500 ms
–cSNRT (SNRT - BCL) < 550 ms
–SNRT/NSR < 150%

21. EPS to evaluate SA conduction
•Sinoatrial conduction time (SACT)
–45~125ms

22. Atrio-ventricular block
•First degree AV block
•Second degree AV block
–Mobitz type I
–Mobitz type II
–Advance AV block: 2:1, 3:1, 4:1,… AV
block
•Three degree (Complete) AV block

23. 1
st
Degree AV block
•Simple prolongation of PR interval (> 0.2
seconds)
•No dropped QRS complexes
•All P waves are conducted

24. 1
st
degree AV block
HR: 57bpm, PR: 350ms

25. 2
nd
degree Mobitz type I AV block
(Wenckebach phenomenon)
•PR interval progressively increases before
dropped QRS
•Intermittent dropping of the QRS
•RR interval may progressively decrease
•Grouping of QRS

26. 2
nd
degree Mobitz type I AV block
(Wenckebach phenomenon)
HR: 44bpm, PR: 292ms

27. 2
nd
degree Mobitz type II AV block
•Fixed PR interval before dropped QRS
complex

28. 2
nd
degree Mobitz type II AV block
HR: 59bpm, PR: 136ms

29. 2:1 AV block
•QRS complex
dropped in every
other beat
•Constant PR
interval
•Mobitz type I or II

30. 2:1 AV block
HR: 41bpm, PR: 192ms

31. HR: 40bpm, PR: 186ms
 2: 1 AV block

32. Three degree (Complete) AV block
•Complete interruption of atrial conduction
•Independent atrial and ventricular rhythms
(AV dissociation)
•Regular PP and RR interval
•Atrial rate > ventricular rate
•P wave march through the QRS
complexes

33. Three degree (Complete) AV block
HR: 43bpm

34. HR: 45bpm
 Complete AV block

35. HR: 67bpm, PR: 207ms
 Non-conducted APC

36. Escape rhythm
•When the ventricles are not stimulated as
a result of automaticity or conduction
problems
•Marked sinus bradycardia, sinus pause,
complete AV block
•Junctional vs. ventricular escape rhythm
–Junctional: narrow, rate: 40~60bpm
–Ventricular: wide, rate: 20~40bpm

37. Escape rhythm
HR: 36bpm

38. Sinus bradycardia with junctional
escape rhythm
HR: 50bpm

39. Complete AV block with ventricular
escape rhythm
HR: 27bpm

40. Atrial fibrillation with slow
ventricular response
•Atrial rate in Af: 350~700bpm
•The ventricular rate depends on the AV
conduction ability
•Impaired AV conduction

41. Atrial fibrillation with slow
ventricular response
HR: 48bpm

42. Af with regular RR interval
 Af with complete AV block and junctional escape rhythm

43. 感恩聆聽 !