Its a medical presentation describing how to approach to various cardiac arrhythmias in systematic way. Illustrated with more ECG photographs from standard sources.

1. Approach to Arrhythmias
Presenter : Dr. Mohammed Jaleel P
Moderator : Prof. Ng Taruni Devi
Regional Institute of Medical Sciences, Imphal

2. INTRODUCTION
• Arrhythmias are one of the common diseases we used to see
in daily practice
• Fatal sometimes if not treated properly or on time
• Becomes diagnostic challenge sometimes
• In addition to history and examination, ECG is more
important, particularly at the time of symptoms.

3. Classification of Arrhythmias
Arrhythmias
Tachyarrhythmias
Narrow QRS Wide QRS
Bradyarrhythmias

4. Narrow QRS Tachyarrthymias

5. Physiologic sinus tachycardia
• >100 Beats/min, tall P waves in inf leads
• Sympathetic stimulation or vagal withdrawal

6. Nonphysiologic sinus tachycardia
• Ill defined conditions causing autonomic dysregulations
• Differentiate from sinus tachycardia & focal atrial
tachycardia
• Rx-Beta blockers / CCBs
• Clonidine, Serotonin Reuptake Inhibitors, Ivabradine

7. Focal Atrial Tachycardia
• Regular atrial tachycardia with defined P wave
• Abrupt onset and offset (diff from sinus tachy)
• AT will not terminate with AV block (from AVRT,AVNRT)
• P wave morphology tells location of focus
• Atrial septum- Narrow p wave
• Left atrium- V1 (monophasic positive), I& avL (negative)
• Superior location – inf leads (positive P)
• Inferior locations – neg p wave

8. Contd…
• Rx:
• Adenosine, Beta blockers, CCB (improve tolerance by AV block)
• Catheter ablation (recurrent symptomatic)

9. Multifocal atrial tachycardia
• At least 3 distinct P wave morphologies
• Irregular beats. Rate 100-150 beats/min,
• Clear isoelectric intervals b/w p waves(unlike AF)
• Multiple atrial foci
• In c/c pulmonary disease, a/c illness
• Treat underlying disease ± CCB (Beta blocker avoided)

10. Mechanisms of various PSVTs

11. • Regular, Narrow complex tachycardia
• P wave in QRS , slightly before or slightly after QRS
AV nodal re-entry tachycardia (AVNRT)

13. Junctional tachycardia
• Automaticity within AV node
• Narrow QRS tachycardia, No P wave
• ± VA block --> AV dissociation

14. AV re-entry tachycardia (AVRT)
• Circulating wavefront reenter atrium
via retrograde conduction through AP
• P wave always follow QRS
• Wide QRS complexes
• Morphology of P wave depending on
pathway location

15. Paroxysmal supraventricular tachycardia
(PSVT)
• Family of tachycardia including AVRT, AVNRT and atrial
tachycardia.
• Sudden run of 3 or more such beats
• 2nd to 4th decade , mostly women
• Often tolerated, sometimes – angina, pulmonary edema,
hypotension, syncope.
• Unstable- sync DC shock (rarely needed)

16. Emergency treatment algorithm (stable PSVT)

17. Atrial flutter
• Neg saw toothed flutter waves in II, III, avF
• Positive P waves in lead V1
• Atrial rate-- 240-300 beats/min
• Usually a/w atrial fibrillation

19. • Re-entry circuit:
• Common Afl – cavotricuspid isthmus dependent
• Atypical Afl -- not dependent
Atrial flutter and fibrillation

20. Atrial fibrillation
• Irregular R-R interval
• No p waves
• Normal QRS morphology

21. Contd…
• Disorganised rapid and irregular atrial activation with loss of
atrial contraction, irregular ventricular rate.
• paroxysmal AF- (<7 days)
• Persistent AF – (>7days, may require cardioversion)
• Permanent AF –(>1 year)
• Risk factors
• ↑Age, HTN, DM, obesity, sleep apnea
• Hyperthyroidism, alcohol, MI

22. Treatment of AF and Afl
• Unstable new onset AF (severe hypotension, pulmonary edema,
angina) sync: DC Shock
• Stable
 < 48 hrs, not at high risk for stroke  cardioversion can be tried
 >48 hrs  consider anticoagulation (CHA2DS2VASc )
• Rate control- beta blockers , CCB
• Digoxin- (esp with cardiac failure)
• Symptomatic / difficult rate ctrl/ ventricular dysfunction
rhythm control (class I/ class III)
• Catheter / surgical ablation

25. Wide complex
tachyarrhythmia
Monomorphic QRS
Ventricular
tachycardia
Supraventricular
tachycardia with
aberrancy
Polymorphic QRS
Torsade de
pointes
Ventricular
fibrillation
Classification of wide QRS complex
tachyarrhythmias

26. • Premature QRS complexes ,Abnormal in shape
• Duration exceeds dominant QRS complex- >120 ms
• ST-T wave large, opposite in direction to deflection of QRS
• Late PVC = compensatory pause
Premature ventricular complexes

27. Ventricular bigeminy and trigeminy

28. Ventricular couplet and triplet

29. Unifocal vs multifocal pvc

30. PVC which suggest structural heart disease:
• With broad notching and slurred QRS complexes
• PVC with RBBB configuration
• Multifocal PVC
Frequency and severity of arrhythmia – severity of
disease

31. Treatment
• Treatment approach to patients with PVCs depends on ± of
symptoms and ± underlying structural heart disease
• Beta blocker , CCB as the first-line drug for treatment
• Other options - antiarrhythmic medications or radiofrequency
catheter ablation
• PVCs associated LV dysfunction- Radiofrequency ablation

32. Accelerated idioventricular rhythm (AIVR)
• Repetitive ventricular rhythm occurring at a rate between 60 and
100 beats per min
• Accelerated ventricular focus that generates an impulse faster
than the sinus node and therefore assumes control
• Fusion beat at onset and termination of arrhythmia
• Common occurs;
• Reperfusion of occluded coronary artery
• Resuscitation

33. • AV dissociation ±, (PP >RR interval)

34. • 3 or more abnormaly shaped PVCs
• >120 msec, ST-T vector opposite the major QRS
deflection
• R-R interval regular, or vary
• Atrial activity – independent, or can be depolarized by
ventricles retrogradely (VA association)
• Rates range 100-250 bpm
• Onset : usually sudden
Ventricular tachycardia (V-tach or VT)

35. Definitions of various v-tachs
• VT: The occurrence of three or more PVC complexes (>
120ms) with a rate of > 120 bpm in succession is called as VT.
• Slow VT - HR >100 & < 120 bpm.
• Non sustained VT : Termination of VT by itself in < 30 sec.
• Sustained VT: for >30 sec. or requiring termination because of
hemodynamical collapse.

36. Contd…
• Pulseless VT – VT with hemodynamic collapse that
requires defibrillation & treated as VF.
• VT storm – repeated VT episodes requiring the DC shocks.
(≥ 3VT/24hrs)
• VF: Rate >220 bpm

37. Sustained Monomorphic VT :
ECG of 72yrs old woman with CHD

38. F C
Fusion beats and capture beats

39. • Concordance: Chest leads, i.e. leads V1-6 show entirely
positive (R) or entirely negative (QS) complexes, with no RS
complexes seen.

40. VT (contd…)
• Brugada’s sign– The distance from
the onset of the QRS complex to the
nadir of the S-wave is >100ms
• Josephson’s sign – Notching near the
nadir of the S-wave
• MORRISON’S Sign: complexes with
(Rr’) a taller left rabbit ear. This is the
most specific finding in favour of VT.

42. Treatment of VT
• Unstable  sync DC shock
• Stable  trial of adenosine (r/o SVT with aberrancy)
• IV amiodarone is DOC if heart disease present
• Evaluate for underlying heart disease
• r/c VT  antiarrythmic or catheter ablation
• Sustained VT with structural heart dis ICD

43. Reversible causes of VT
• Hypoxia
• Hypothyroidism/ hyperthyroidism
• Hypokalemia
• Metabolic acidosis
• Hypomagnesemia
• Hypocalcemia
• Drugs
• Alcohol
• Starvation

45. Wolf Parkinson white syndrome
• Short P-R interval (<0.12s)
• Slurred initial portion of QRS (delta wave)
• Prolonged QRS duration
• Accessory pathway connecting
atrium and ventricle
across valve ring
• Mc- b/w left atrium and free wall
of left ventricle

46. Contd…

48. Sustained Polymorphic VT

49. Torsade de pointes
• Arrhythmia a/w Long QT Syndrome – Polymorphic VT called
TdP.
• The peaks of the QRS complexes appear to "twist" around the
isoelectric line of the recording,
hence the name torsade de pointes or "twisting about the
points."

51. Contd…
• Prolonged QT interval in the last sinus beat preceding the
onset of the arrhythmia, a ventricular rate of 160 to 250 bpm,
irregular RR intervals
• Torsades de pointes episodes usually are short-lived and
terminate spontaneously. Some times progress to VF
• r/c episodes – IV MgSO4 1-2g.

52. Idiopathic VT
• Idiopathic VT refers to any VT that is not associated with
structural heart disease
• Outflow tract VT - triggered automatic arrhythmias- RVOT-
LBBB
• Fascicular VT- reentrant arrhythmias within the Purkinje
system- LV- RBBB
• Treatment- beta blockers
CCB- Verapamil
• Not effective/severe symptoms --Catheter ablation

53. Ventricular fibrillation
• Most frequent mech of sudden cardiac death (SCD).
• Rapid, disorganized ventricular arrhythmia, resulting in no
uniform ventricular contraction, no cardiac output, and no
recordable blood pressure.
• The ECG in VF shows rapid (300 to 400 beats/min), irregular,
shapeless QRST undulations of variable amplitude, morphology
and interval.
• ACLS guideline with defibrillation -> sinus rhythm
• If no reversible cause identified  consider ICD

57. Sinus bradycardia
• Sinus rhythm.
• Heart rate<60 beats/min

58. SA node dysfunction
• Sinus pause & Sinus arrest
• Sinus pause of <3sec is common in awake athletes
• Sinus exit block
• Intermittent conduction from SA node
• Can be classified similar to AV blocks
Sick sinus syndrome (SSS)
• Dysfunction of SA node often secondary to senescence of
SAN or surrounding myocardium

59. Sinus pause

60. 2nd degree Sinus block

61. 1st degree AV block
All P waves are conducted
• Each P followed by QRS
• PR interval is uniformly prolonged (>200 ms)

62. Second degree AV block
Intermittently droped QRS complexes
(mobitz type 1)-Wenckebach pattern
• PR interval progressively lengthens until 1P wave is not conducted
• PR interval after nonconducted beat is shorter
• Ratio of number of P wave to QRS as nomenclature

63. Contd…
Mobitz type II
• PR intervals of conducted beats are constant
• Occasional P waves without following QRS

64. 3rd degree (complete) heart block
No stimuli transmitted from atria to ventricle
• Independent atrial and ventricular activity

65. Junctional escape rhythm
• No P wave apparent
• Heart rate 40-60 beats/min
• Regular Narrow QRS complexes

66. Ventricular escape rhythm
• No P wave (rarely neg P after QRS)
• Ventricular rate <40 beats/min
• regular Wide QRS complexes

67. Atrial fibrillation with slow ventricular
response
• No P wave
• Irregular narrow QRS complexes
• Ventricular rate <60beats/min

68. Conclusion
• Arrhythmias are one of the commonly encountered problems
in clinical practice
• Cardiac arrhythmias result from abnormality of impulse
generation or conduction or both
• ECG can differentiate between most of the arrhythmias.
• Rate, QRS width, regularity of R-R interval and P wave all
are important in approaching arrhythmias.

69. References …
• Harrisons principles of internal medicine, 20th edition
• Goldberger’s clinical electrocardiography, 9th edition
• UpToDate,

70. THANK YOU

71. Prepared by: Dr. Mohammed Jaleel P
Dept. of General Medicine
Regional Institute of Medical Sciences, Imphal
pmjaleelvld@gmail.com
Ph.: 9633882581