by Salah Abusin, MD, Cardiology Fellow, Cook County Hospital, Chicago, IL

1. Arrhythmias in Real Life
Narrow Complex Tachycardias
Salah Abusin, MBBS, MRCP (UK), ABIM
Cardiology Fellow
Chicago, IL,USA

2. Outline
• Types
• Mechanism of Tachyarrhythmias
• ECG Interpretation & Acute Management
• Algorithm for Management of NCTs
• Problems

3. Types
Atrial Tissue AV Junction (Supraventricular)
• Sinus Tachycardia • AV nodal Reentry Tachycardia
• Atrial Tachycardia • AV Reentry Tachycardia
• Multifocal Atrial Tachycardia Pre Excitation Syndromes
• Atrial Flutter • WPW
• Atrial Fibrillation • Permanent Junctional Reentry
• Sinus Node Reentry Tachycardia tachycardia
• Inappropriate Sinus Tachycardia • Mahaim tachycardia
• Lown-Ganong- Levine Syn.

4. Mechanisms of tachyarrhythmias
1. Automaticity
2. Triggered Activity
3. Reentry

5. Automaticity
• Normal
– SA Node
– AV Node
• Abnormal
– Idioventricular rhythm

6. Reentry
• Requires the presence
of two pathways
– One slow, the other fast
– Unidirectional block in
one of the pathways
– Slow conduction down
the unblocked pathway
allowing the other
pathway to recover and
maintain the circuit

7. Triggered Activity
Delayed After Depolarization
• Early
– Prolonged QT
– Torsades de Pointes
• Late
– Digoxin Toxicity

8. Narrow Complex Tachycardia
Irregular Regular
No P Waves P Waves present
Atrial Fibrillation
Multifocal Atrial Tachycardia
Atrial Flutter with variable block

9. Atrial Fibrillation

10. Atrial Fibrillation
• Irregular Narrow Complex Tachycardia
• The commonest sustained arrhythmia
• Absence of P waves
• Atrial activity appears as irregular baseline or f
(fibrillatory) waves
• Usual ventricular rate 100-180 in the absence of
therapy
• If HR < 100 without medical treatment suspect
underlying conductive tissue disease

11. Types
• Paroxysmal
– self-terminating episodes that generally last <7 days
(most <24 hours)
• Persistent
– generally lasts >7 days and often requires electrical or
pharmacologic cardioversion.
• Permanent
– failed cardioversion or when further attempts to
terminate the arrhythmia are deemed futile.
Hurst's the Heart, 12th Edition

12. Causes
• Ischemic Heart Disease
• Hypertensive Heart Disease
• Other organic heart disease/cardiomyopathy
• Mitral Valve disease
• ASD
• WPW
• Lung Disorders (Acute e.g. PE, Chronic e.g. COPD)
• Post Surgical e.g. CABG
• Thyrotoxicosis
• Alcohol

13. II aVL V2
III aVF V3
V1
P P P P P P P
II
V5
25mm/s 10mm/mV 100Hz 005D 12SL 233 CID: 31 EID:34 EDT: 09:14 16-M
Multifocal Atrial Tachycardia

14. Multifocal Atrial Tachycardia
(MAT)
• Irregular Narrow Complex Tachycardia
• >= 3 P wave morphologies
• Varying PP, PR, RR intervals
• P waves may be blocked
• P waves may conduct with aberrancy
• Unstable rhythm usually progresses to atrial
fibrillation

15. Causes
• COPD
• Cor pulmonale
• Hypoxia
• Heart Failure
• Postoperative State
• Sepsis
• Pulmonary Edema

16. Management
• Treatment of the underlying cause
• Correction of electrolytes (K, Mg)
• AV nodal blocking agents
• Anticoagulation depending on stroke risk

17. Narrow Complex Tachycardia
Irregular Regular
No P Waves P Waves present
AV nodal Reentry Identify P wave morphology/rate
tachycardia, AVNRT Relationship between P and QRS
Identify RP interval

18. AV nodal Reentry Tachycardia

19. AVNRT
• Regular Narrow Complex Tachycardia
• Usual rate 150-250
• Abrupt onset and offset
• Variable relation to P wave
– P wave buried in the QRS
– Short RP interval
– Atypical AVNRT Long RP
• Usually no underlying heart disease

20. Mechanism of AVNRT

21. Management
• Acute Episode
– Vagal Maneuvers
• Valsalva, carotid sinus massage,
– IV adenosine
– IV/PO Betablockers, Calcium Channel Blockers
– DC Cardioversion
• Prevention
– PO Betablockers, Calcium Channel Blockers
– Radiofrequency Ablation

22. Narrow Complex Tachycardia
Irregular Regular
No P Waves P Waves present
Identify P wave morphology/rate
Relationship between P and QRS
Identify RP interval

23. RP Interval
• Distance from the R wave to the NEXT P wave
• Short if RP interval < ½ RR interval
• Long if RP interval > ½ RR interval

24. Long RP Interval
RP interval > ½ RR interval
RR
RP

25. Short RP interval
RP interval < ½ RR interval
RR
RP

26. Regular Narrow Complex Tachycardia
P wave morphology
Atrial rate
Relationship between
No P Waves P Waves present P and QRS
RP interval
Atrial rate >200 Short RP Long RP interval
Flutter waves Abnormal P wave Abnormal P wave
Atrial Flutter Atrial tachycardia Atrial tachycardia
With AV delay
Short RP Long RP interval
Retrograde P wave Retrograde P wave
AVNRT, AVRT Atypical AVNRT

27. Definition of normal P
• Duration 0.08 to 0.11 (2-3 small squares)
• Axis (0-75)
• Upright in II, III, aVF
• Upright/biphasic in III, aVL, V1, V2
• Amplitude <2.5mm in II (2.5 small squares)
• Amplitude in V1 positive <1.5mm (1.5 small sq)
negative <1mm (1 small sq)
• PR interval 0.12 – 0.2 (3-5 small squares)

28. RR
P P P P RP
AV node reentry tachycardia, AVNRT

29. F F F F F
Atrial Flutter

30. Atrial Flutter
• Regular Narrow Complex Tachycardia
• Flutter waves conducting ~ 300/min
• Usually 2:1 block with a ventricular response
of 150/min
• Same causes as atrial fibrillation
• No baseline in II, III, aVF
• Discrete P waves in V1

31. Mechanism of Atrial Flutter
• Typical F waves inverted
F waves in II, III, aVF

32. Management
• Similar to atrial fibrillation
– Requires anticoagulation
• More Difficult to control rate with medical
treatment compared to atrial fibrillation
• Usually requires DC Cardioversion
• Radiofrequency ablation highly successful in
restoration and maintenance of sinus rhythm

33. RR RP
P P P P
Atrial Tachycardia

34. Atrial tachycardia
• Atrial rate is 100-240 i.e. slower than atrial flutter
• Usually 1:1 conduction without medical
treatment
• Not terminated by vagal maneuvers
• Mechanism
– Intra atrial reentry
– Automatic – ectopic focus
– triggered

35. Management
• AV nodal blocking agents
• Some are amenable to Radiofrequency
ablation

36. ECG PROBLEMS

37. Problem 1
• 68 year old Nigerian male with PMH of HTN,
DM comes to Cardiology clinic for a routine
check up
• He takes metoprolol in addition to Lisinopril
for Blood Pressure Control
• HR 70/min, irregular, BP 150/70

38. • Regularity of rhythm
• P wave present or absent Atrial
Fibrillation

39. Problem 2
• 62 year old female with known ESRD on HD
via left AV fistula developed sudden onset of
palpitations during dialysis; feels her HR racing
• HR 170/min, BP 130/80
• Clinical Examination revealed rapid regular
heart beat, mild LE edema, left AV fistula

40. • Regularity of rhythm
• P wave present or absent
•
•
RP interval
P wave morphology/rate AVNRT
• Relationship between P and QRS

41. Problem 3
• 59 year old African American Male, with DM,
HTN, Obesity presents to his internist with
two weeks history of shortness of breath on
exertion
• HR 140/min, BP 140/90
• JVP difficult to assess due to obesity
• Chest clear, mild LE edema (unchanged
according to patient)

42. • Regularity of rhythm
• P wave present or absent Atrial
• RP interval
• P wave morphology/rate Flutter
• Relationship between P and QRS

43. Problem 4
• 74 year old African American Female with
remote history of ASD repair and Pulmonary
Hypertension comes for follow up
• She takes metoprolol for hypertension
• HR 80/min, BP 120/70

44. • Regularity of rhythm
• P wave present or absent Atrial
• RP interval Tachycardia
• P wave morphology/rate
• Relationship between P and QRS
with 2:1 Block

45. Problem 5
• 52 year old Middle Eastern Female with
known non ischemic cardiomyopathy is
admitted with heart failure exacerbation
• HR 105/min, BP 100/60
• JVP raised, bibasal crackles, and bilateral LE
edema 2+

46. • Regularity of rhythm
•
•
P wave present or absent
RP interval
Atrial
• P wave morphology/rate Fibrillation
• Relationship between P and QRS

47. Problem 6
• 54 year old White Male with PMH of a known
arrhythmia comes for routine follow up
• He takes metoprolol XL 200mg once daily
• HR 110/min, irregular, BP 130/70

48. • Regularity of rhythm
• P wave present or absent Atrial Flutter
• RP interval with variable Block
• P wave morphology/rate
• Relationship between P and QRS

49. Problem 7
• 49 year old male with no PMH, presents to the
Emergency Room with sudden onset of
palpitations, headache
• HR 145/min, BP 140/90

50. • Regularity of rhythm
• P wave present or absent
• RP interval
•
•
P wave morphology/rate
Relationship between P and QRS
AVNRT

51. Problem 8
• 36 year old African American Male with no
PMH comes for a routine outpatient visit to
his primary care doctor
• HR 115/min, BP 120/80

52. • Regularity of rhythm
• P wave present or absent Atrial
•
•
RP interval
P wave morphology/rate
Tachycardia
• Relationship between P and QRS with 2:1 Block

53. Problem 9
• 61 year old Hispanic female with no PMH,
presents to the Emergency Room with fatigue,
loss of weight, palpitations, and feeling warm
all the time.
• HR 200/min, BP 120/80

54. • Regularity of rhythm
• P wave present or absent Atrial
•
•
RP interval
P wave morphology/rate
Fibrillation
• Relationship between P and QRS

55. Problem 10
• 48 year old male with severe obesity, a
chronic skin disorder, and chronic LE edema is
sent to hospital from this primary care doctor
after he finds his HR to be very fast
• HR 141/min, BP 130/70
• In the ER an ECG was performed
• Due to concerns for Pulmonary Embolism (PE),
a CT Pulmonary Angiogram was performed
and was reported as negative for PE

56. • Regularity of rhythm
• P wave present or absent
• RP interval Atrial
• P wave morphology/rate Tachycardia
• Relationship between P and QRS

57. • Diagnosed with probable ectopic atrial
tachycardia
• No response to IV adenosine
• No response to IV esmolol
• NO response to IV amiodarone
• Started becoming more breathless

58. • Performed DC Cardioversion 50J Biphasic, then 200
with no response
• At second attempt at DC Cardioversion 200J reverted
to Sinus rhythm

60. THANK YOU