Tachydysrhythmias

1. Tachyarrythmias
Ali Mackay

3. QUIZ!!

4. Q1

5. Q2

6. Q3

7. Q4

8. Q5

9. Q6

10. Q7 - a 6 year old

11. Q8

12. Q9

13. Q10

14. Q11

15. Tachyarrythmias
Ali Mackay

18. Sinus tachycardia
“camel hump” appearance
P before every QRS
Usually 100-160 (up to 220)

19. Shock
Hypoxia
Anaemia
Drug intox/wd esp
Tetanus
Pheochromocytoma
Cardiac Failure
Fever/infection (8
beats per 1°↑)
Pain, anxiety
Thyrotoxicosis
Pregnancy
Delerium
ST - Causes

22. Atrial flutter with 4:1 block
Vent rate 65

23. Usually atrial rate between
250-350bpm
Single reentrant circuit in
the right atrium
“Sawtooth pattern” esp II, III
No isoelectric line between
flutter waves
Atrial Flutter

24. Atrial flutter: 2 types
Anticlockwise reentry (70%)
Flutter waves inverted in II, III and aVF (Type
1)
Clockwise reentry (30%) upright
in same leads (Type 2)
rarely occurs in absence of underlying heart
disease
2:1 = vent rate 150 (commonest)
3:1, 4:1

25. Causes- atrial flutter
IHD
Acute MI
CCF
PE
Myocarditis
Chest trauma
Digoxin toxicity

27. Atrial flutter with variable block
May mimic Atrial fibrilllation
alternating 3:1 and 4:1

29. Or rapid SVT with rate related ST depression
Very rapid, regular narrow complex
tachycardia
Undulating baseline
Usually occurs due to sympathetic stimulation
with an accessory pathway. Eg AV nodal
drugs given to WPW
Can progress to VF
Atrial flutter 1:1

30. DC cardiovert!
Treatment?

32. Atrial flutter with high grade block
Marked AV block 5:1 up to 8:1
V. low vent rate ?AV nodal blocking drug
-? digoxin

34. Atrial fibrillation
irregularly irregular
course fibrillatory waves in V1
ST “sagging” in V6, II, III and aVF
? digoxin effect

36. Common in COPD
rapid, irregular with multiple P wave
morphologies
Bonus: Right axis deviation, RVH (dominant R
wave in V1, deep S wave in V6) - cor
pulmonale
Multifocal Atrial
Tachycardia (MAT)

38. Narrow complex tachy - about 150bpm
no P waves
Slow -fast AVNRT (Atrioventricular Nodal
Reentrant Tachycardia)

39. Type of paroxysmal supraventricular
tachycardia (PSVT)
Commonest type of PSVT 80-90%
Caused by reentry circuit in or around the AV
node: slow and fast pathway.
AVNRT

40. AVNRT: 2 types
Slow-fast AVNRT :
commonest, 80-90%
Fast-slow AVNRT : 10%
of AVNRT

42. Slow-fast AVNRT
Slow pathway for anterograde, fast for
retrograde
Retrograde p waves obscured/hidden in QRS
OR at the end of a QRS = “pseudo R or S”
waves
pseudo R waves in V1-2
Pseudo S waves in II, III or aVF

44. Anterograde conduction is via fast, retrograde
via slow
Narrow complex tachy with retrograde P
waves appear after QRS eg V2 and 3
QRS-P-T complexes
Fast- slow AVNRT

45. 6 year old

46. 280bpm, broad complexes
regular broad complex tachycardia
could be VT but.... only 6 years old!
AVRT

47. Also a PSVT
But an AVNT (Atrioventricular Reentry
Tachycardia)
Wolff Parkinson-White

48. Accessory internodal tracts - bundle of kent
Reentry circuit formed by normal conduction via
AV node and accessory pathway
Wolff- Parkinson White

49. In Sinus rhythm

51. WPW Type A
Sinus rhythm, V. short PR interval
Broad QRS compex with slurred upstroke “Delta wave”
Dominant R in V1 = Left sided accessory pathway
Tall R waves and inverted TW in V1-3 just WPW, not RVH
“pseudo infarction” in AVL - negative delta wave, not Q

53. SR, short PR
Broad complex slurred upstroke/ delta wave
Dominant S in V1 - Type B, Right sided
accessory pathway
LVH looking Tall Rs and inverted Ts inferiorly -
just WPW

54. AVRT

56. Orthodromic AVRT
Commonest. Looks like AVNRT!
Rate 225 usually between 200-300bpm
P waves maybe buried in QRS
QRS usually narrow <120ms - impulses
transmitted via AV node
TW inversion common, ST depression
Patient might be stable!

58. Antidromic AVRT
In a 6 year old
Therefore unlikely to be VT but very difficult to
distinguish
Reverted with vagal manouvres

60. AF with WPW vs AF with LBBB
rapid 200bpm irregular tachycardia
but too rapid (to be conducted via AV node)
beat to beat variation with QRS width (LBBB
usually fixed width)

61. Can occur in 20% of WPW
Accessory pathway means AF can be
transmitted to ventricles 1:1 fashion
Rate >200bpm
irregular
Wide QRSm change in shape and morphology
AF and WPW

62. NO:
Adenosine
Beta blockers
CCBs
Digoxin
Lignocaine
YES:
DC cardioversion
?Amiodarone
Treatment of AF and
WPW

64. Also AF with WPW vs polymorphic VT?
300bpm in some places
AV nodal conduction in V1 and 2 with
Narrow/atrial complexes

65. Absence of normal BBB Morphology
Extreme access deviation
Very broad QRS complex >160ms
Capture beats
Fusion beats
Brugada’s sign
Josephson’s sign V6
RSR complexes with a taller L rabbit ear (specific) V1
Features of VT

67. Capture beat
And -ve in
III and aVF
Extreme axis
deviation.
QRS +ve in aVR
Fusion beat

68. Extreme axis deviation
Fusion beats
Capture beats
Brugada’s sign - in V6 - time from onset of
QRS to nadir of S wave is >100ms
Monomorphic VT

70. Josephson
sign
RSR pattern

71. Monomorphic VT
Uniform QRS - very broad >200ms
Josephson’s sign in lead III

72. Age >35
Structural heart disease
Ischaemic heart disease
Prev MI
CCF
Cardiomyopathy
FHx Sudden cardiac death
Clinical features
suggestive of VT

74. Sinus tachy, grossly prolonged PR interval - P
waves hidden in Prev T or QRS complex
QRS v broad about 200ms - but broad in the
terminal portion of the QRS
No positive brugada criteria
+ve R in AVR
TCA toxicity

76. Sinus rhythm, inverted T waves, u waves
Long Q-U interval = hyopkalaemia
Premature atrial beat
R-on-T phenomenom
Torsades du pointes

77. For TdP to be diagnosed, ECG confirmation of
Long QT must be sought (before or after
rhythm is reverted)

78. Use the QTc
Estimates the QT interval at a HR of 60
Bazett’s formula easiest: QTc/√RR
(Where RR interval (secs) = 60/HR)
Prolonged: Men >440ms
Women >460ms
>500ms: at inc risk of TdP
Long QT

79. ↓ K
↓Mg
↓Ca
↓Temp
↑ICP
Post cardiac arrest
Drugs: quinidine
phenothiazines
antihistamines TCAs
Chloral hydrate
erythromycin
azithromycin
fluconazole
Congenital Long QT
Myocardial ischaemia
Causes of Long QT

81. Paced ventricular rhythm with pacing spikes