perioperative arrhythmias

1. PERIOPERATIVE ARRHYTHMIAS
Guided By- Dr. Vijeta khandelwal
Presented By-Dr. C.L. khedia

2. • Definition: Arrhythmia is defined as
"Abnormality of cardiac rate, rhythm or
conduction.
• Cardiac arrhythmias are the most frequent
perioperative cardiovascular abnormalities
in patients undergoing both cardiac and
non-cardiac surgery.
• The occurrence of arrhythmias have been
reported in 70% of patients subjected to
general anaesthesia for various surgical
procedures.

3. Mechanisms of Arrhythmia
Production
• Re-entry (refractory tissue reactivated due to conduction
block, causes abnormal continuous circuit. eg accessory
pathways linking atria and ventricles in Wolff-Parkinson-
White syndrome)
• Injury or damage (pathology) to the cardiac conduction
systems
• Abnormal pacemaker activity/ automaticity in non-
conducting/conducting tissue (eg. ischaemia)
• Delayed after-depolarisation (automatic depolarisation of
cardiac cell triggers ectopic beats, can be caused by drugs
eg digoxin)

4. Contributing factors and causes
1. Patient related factors-
• preexisting cardiac disease
• central nervous system disease
• Old age
2.Anaesthesia related factors
• Tracheal intubation
• general anaesthetics
• regional anaesthesia
• Electrolyte imbalance and abnormal arterial
blood gases
• Central venous cannulation

5. Reversible cause of arrhythmia
• Hypoxemia
• Hypercarbia
• Hypotension
• Acidosis
• Light anesthesia
• Proarrhythemic drugs
• Cardiac ischemia
• Electrolyte imbalance
• Hypothermia
• Mechanical irritation:
PAC, Chest tube

6. Classification of Cardiac
Arrhythmias
• Heart rate (increased/decreased)
• Heart rhythm (regular/irregular)
• Site of origin (supraventricular / ventricular)
• Complexes on ECG (narrow/broad)

7. • Bradyarrhythmias
• Sinus bradycardia
• Sinoatrial block
• Sinus arrest
• Atroventricular block
• Bundle branch block
• Tachyarrhythmias
• Supraventricular arrhythmias
• Ventricular arrhythmias

8. Supraventricular tachyarrhythmias
• Sinus tachycardia
• Prematue atrial contractions (PACs)
• Atrial tachycardia
• Atrial flutter/fibrillation (AF)
• Atrioventricular nodal reentrant tachycardia (AVNRT)
• Atrioventricular reentrant tachycardia (AVRT)
Ventricular tachyarrhythmias
• Premature ventricular contractions (PVCs)
• Ventricular tachycardia (VT)
• Monomorphic vs Polymorphic VT
• Ventricular flutter/fibrillation (VF)

9. Anaesthetic considerations
• All patients undergoing anaesthesia and
surgery should have ECG monitoring.
• Lead II and V 5 are superior for arrhythmia
detection and diagnosis before the
appearance of physical signs.

11. Waveform Analysis
– For each strip it is necessary to go through steps
to correctly identify the rhythm
1. Is there a P-wave for every QRS?
• P-waves are upright and uniform
• One P-wave preceding each QRS
2. Is the rhythm regular?
• Verify by assessing R-R interval
• Confirm by assessing P-P interval
3. What is the rate?
• Count the number of beats occuring in one minute
• Counting the p-waves will give the atrial rate
• Counting QRS will give ventricular rate

12. • Normal
– Heart rate = 60 – 100 bpm
– PR interval = 0.12 – 0.20 sec
– QRS interval <0.12
– SA Node discharge = 60 – 100 / min
– AV Node discharge = 40 – 60 min
– Ventricular Tissue discharge = 20 – 40 min

13. • Cardiac cycle
– P wave = atrial depolarization
– PR interval = pause between atrial and
ventricular depolarization
– QRS = ventricular depolarization
– T wave = ventricular depolarization

14. Normal Sinus Rhythm
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
60 -
100
Regular
Before each QRS,
Identical
.12 - .20 <.12
Sinus Rhythms

15. • Normal Sinus Rhythm
– Sinus Node is the primary pacemaker
– One upright uniform p-wave for every QRS
– Rhythm is regular
– Rate is between 60-100 beats per minute
Sinus Rhythms

16. Sinus Bradycardia
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
<60 Regular
Before each QRS,
Identical
.12 - .20 <.12
Sinus Rhythms

17. • Sinus Bradycardia
– One upright uniform p-wave for every QRS
– Rhythm is regular
– Rate less than 60 beats per minute
• SA node firing slower than normal
• Normal for many individuals
• Identify what is normal heart rate for patient
Sinus Rhythms

18. Perioperative causes of Sinus Bradycardia-:
1. Vagal stimulation- Oculocardiac reflex, Celiac
plexus stimulation(traction on mesentry),
laryngoscopy, Abdominal insufflation, Nausea
and ECT
2. Drugs- Beat blocker, Cal channel blocker, opioids
(fentanyl/sufentanyl)
3. Succinylcholine 4.Hypothermia
5. Hypothyroidism 6. Atheletic heart syndrome
7. SA node disease or ischemia

19. Perioperative T/T-
- In asymptomatic pt no t/t requires
- In Mildly symptomatic pts, underlying factors
should be eleminated
- In severly symptomatic pts, those with chest pain
or syncope, immediate
transcutaneous/transvenous pacing is required.
- Atropine 0.5 mg Iv every 3-5 min(max 3mg) may
be given. It should be noted dose of atropine
(<0.5mg) can cause further slowing of HR.
- An epinephrine or dopamine infusion may be
titrated while awaiting cardiac pacing.

20. •
Sinus Tachycardia
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
>100 Regular
Before each QRS,
Identical
.12 - .20 <.12
Sinus Rhythms

21. • Sinus Tachycardia
– One upright uniform p-wave for every QRS
– Rhythm is regular
– Rate is greater than 100 beats per minute due to
increased SA node discharge sec. to sympathetic
stimulation (physiological/pathological
/pharmacological response)
• Usually between 100-160 (>160 SVT)
• Can be high due to anxiety, stress, fever, medications
(anything that increases oxygen consumption)
Sinus Rhythms

22. Treatment-:
-correcting underlying cause of symp. Stimulation.
-Beta blockers may be employed to lower heart rate
and decrease myocardial o2 demand(if pt is not
hypovolemic).
-supplemental O2 to increase supply in response to
increase demand.
-Avoidance of vagolytic drug (pancuronium)
intraoperatively

23. Sinus Arrhythmia
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
Var. Irregular
Before each QRS,
Identical
.12 - .20 <.12
Sinus Rhythms

24. • Sinus Arrhythmia
– One upright uniform p-wave for every QRS
– Rhythm is irregular
• Rate increases as the patient breathes in
• Rate decreases as the patient breathes out
– Rate is usually 60-100 (may be slower)
– Variation of normal, not life threatening
Sinus Rhythms

25. Premature Atrial Contraction (PAC)
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
NA Irregular
Premature &
abnormal or
hidden
.12 - .20 <.12
Atrial Rhythms

26. – Premature Atrial Contraction (PAC)
• One P-wave for every QRS
– P-wave may have different morphology on ectopic beat,
but it will be present
• Single ectopic beat will disrupt regularity of
underlying rhythm
• Rate will depend on underlying rhythm
• Underlying rhythm must be identified
• Classified as rare, occasional, or frequent PAC’s
based on frequency
Atrial Rhythms

27. • Sign and symptoms
-PACs arises from ectopic foci in atria. Typical
symptoms include an awareness of a fluttering
or a heavy heart beat.
-Precipitated by excessive caffeine, stress,
alcohol, nicotine and hyperthyroidism.
-Often occur at rest and become less frequent
by exercise.
-second most arrhythmias asso. With MI.

28. Perioperative T/t-:
1. Avoidance of ppt. factors and sympathetic
stimulation.
2. Pharmacological T/t required only if the PACs
trigger sec. dysrhythmias.
3. Usually suppressed by calcium channel
blocker or Beta blocker.

29. Atrial Fibrillation
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
Var. Irregular Wavy irregular NA <.12
Atrial Rhythms

30. • Atrial Fibrillation
– No discernable p-waves preceding the QRS complex
• The atria are not depolarizing effectively, but fibrillating
– Rhythm is grossly irregular
– If the heart rate is <100 it is considered controlled a-
fib, if >100 it is considered to have a “rapid ventricular
response”
– AV node acts as a “filter”, blocking out most of the
impulses sent by the atria in an attempt to control the
heart rate
Atrial Rhythms

31. • Atrial Fibrillation (con’t)
– Often a chronic condition, medical attention only
necessary if patient becomes symptomatic
– Patient will report history of atrial fibrillation.
– Symptoms range from palpitation to angina
pectoris, CHF, pul. Oedema and hypotension
– Often associated with fatigue and generalized
weakness.
– Predisposing factors are :RHD, hypertension,
thyrotoxicosis, IHD, chronic COPD, pericarditis
and pulmonary embolus.
Atrial Rhythms

32. Perioperative management-
-If new onset of AF, surgery should be postponed if possible
untill control of dysrhythmia.
-T/t of AF during Sx depends on hemodynamic stability of pt.
-if hemodynamically significat, the T/t is cardioversion
-Synchronized electrical cardioversion (100 to 200 J) is most
effective.
-Pharmacological cardioversion by IV amiodarone (pref.drug),
diltiazem or verapamil may be attempted.
-Pt with chronic AF should be maintained on their
antidysrhythmic drugs with close attention to serum
electrolyte(K &Mg).
-Manage the transition on and off IV and oral anticoagulation.

33. Atrial Flutter
Heart Rate Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
Atrial=250
– 400
Ventricular
Var.
Irregular Sawtooth
Not
Measur-
able
<.12
Atrial Rhythms

34. • Atrial Flutter
– More than one p-wave for every QRS complex
• Demonstrate a “sawtooth” appearance
– Atrial rhythm is regular. Ventricular rhythm will be
regular if the AV node conducts consistently. If the
pattern varies, the ventricular rate will be irregular
– Rate will depend on the ratio of impulses conducted
through the ventricles
– Most commonly atrial rate compared to ventricular
rate 2:1 (if atrial rate is 300bpm and 2:1 conduction,pt
can present with venticular rate of 150 with sign and
symptoms)
Atrial Rhythms

35. • Peioperative T/t-
-T/t depends on hemodynamic stability of
patient.
-If AF is hemodymamically sig. the T/t is
cardioversion, synchronized elec. Cardioversion
satarting at 50 J is indicated.
-Pharmacological control of ventricular response
with IV amiodarone, diltiazem or verapamil may
be tried, if vital signs are stable.

36. Atrial Rhythms
• Atrial Flutter
– Atrial flutter is classified as a ratio of p-waves
per QRS complexes (ex: 3:1 flutter 3 p-waves
for each QRS)
– Not considered life threatening, consult
physician if patient symptomatic

37. • Rhythms that originate at the AV junction
• Junctional rhythms do not have
characteristic p-waves.
Junctional Rhythms

38. Premature Junctional Contraction PJC
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
Usually
normal
Irregular
Premature,
abnormal, may be
inverted or hidden
Short
<.12
Normal
<.12
Junctional Rhythms

39. • Premature Junctional Contraction (PJC)
– P-wave can come before or after the QRS complex,
or it may lost in the QRS complex
• If visible, the p-wave will be inverted
– Rhythm will be irregular due to single ectopic beat
– Heart rate will depend on underlying rhythm
– Underlying rhythm must be identified
– Classify as rare, occasional, or frequent PJC based
on frequency
– Atria are depolarized via retrograde conduction
Junctional Rhythms

40. Accelerated Junctional
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
Var. Regular
Inverted, absent or
after QRS
<.12 <.12
Junctional Rhythms

41. • Accelerated Junctional Rhythm
– P-wave can come before or after the QRS
complex, or lost within the QRS complex
• If p-waves are seen they will be inverted
– Rhythm is regular
– Heart rate between 60-100 beats per minute
• Within the normal HR range
• Fast rate for the junction (normally 40-60 bpm)
Junctional Rhythms

42. Junctional Tachycardia
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
>100 Regular
May be inverted or
hidden
Short
<.12
Normal
<.12
Junctional Rhythms

43. • Junctional Tachycardia
– P-wave can come before or after the QRS complex or
lost within the QRS entirely
• If a p-wave is seen it will be inverted
– Rhythm is regular
– Rate is between 100-180 beats per minute
• In the tachycardia range, but not originating from SA node
– AV node has sped up to override the SA node for
control of the heart
– Junctional rhythm often result in AV dyssynchrony
and a junctional tachycardia can severly impaired
Cardiac output.
Junctional Rhythms

44. • Perioperative T/t-
-Junctional rhythm is not frquent during GA.
-Transient Junctional rhythm require no T/t
-Loss of AV synchrony during a junctional
rhythm may result in MI, heat failure or
hypotension
-Atropine 0.5 mg can be used to treat
hemodynamically significat junctional rhythms

45. Ventricular Rhythms
Premature Ventricular Contraction (PVC)
Heart
Rate
Rhythm P Wave
PR
Interval
(sec.)
QRS
(Sec.)
Var. Irregular
No P waves
associated with
premature beat
NA
Wide
>.12

46. Ventricular Rhythms
• Premature Ventricular Contraction (PVC)
– The ectopic beat is not preceded by a p-wave
– Irregular rhythm due to ectopic beat
– Rate will be determined by the underlying rhythm
– QRS is wide and may be bizarre in appearance
– Caused by a irritable focus within the ventricle which
fires prematurely

47. Ventricular Rhythm
• Premature Ventricular Contraction
– Classify as rare, occasional, or frequent
– Classify as unifocal, or multifocal PVC’s
• Unifocal-originating from same area of the
ventricle; distinguished by same morphology

48. Ventricular Rhythm
• Premature Ventricular Contraction
– Classify as unifocal, or multifocal PVC’s
– Unifocal-originating from same area of the
ventricle; distinguished by same morphology
– Multifocal-originating from different areas of the
ventricle; distinguished by different morphology

49. Ventricular Rhythm
• Premature Ventricular Contraction
– Bigeminy
• A PVC occurring every other beat
– Also seen as Trigeminy, Quadrigeminy

50. Ventricular Rhythm
• Dangerous PVC’s
– R on T
– Runs of PVC’s
– 3 or more
considered Vtach

51. • Causes of PVCs
- Arterial hypoxemia
- MI
- Myocarditis
- SNS activation
- Hypokalemia/Hypomagnesemia
- Digitalis toxicity
- Caffeine, cocaine,Alcohol
- Mechanical irritation-(CV or Pulm. Artery
catheter)

52. • Prioperative T/t-
-During anaesthesia, if pt exhibits 6 or more PVCs
per minute and repetetive or multifocal forms,
there is increased risk of developing life
threatining dysrhythmia.
-T/t include a D/d of possible cause and t/t of that
cause, while t/t of cause, the immediate
availability of a defibrillator should be confirmed.
-Beta blockers are the most successful drug,
amiodarone,lidocaine and other antiarhythmic
are indicated if the PVCs progress to VT or
ferquent to cause hemodynamic instability.

53. Ventricular Rhythms
Ventricular Tachycardia
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
100 –
250
Regular
No P waves
corresponding to QRS,
a few may be seen
NA >.12

54. Ventricular Rhythms
• Ventricular Tachycardia
– No discernable p-waves with QRS
– Rhythm is regular
– Atrial rate cannot be determined, ventricular
rate is between 150-250 beats per minute
– Must see 4-6 beats in a row to classify as v-
tach

55. Ventricular Rhythms
• Ventricular Tachycardia
– THIS IS A DEADLY RHYTHM
• Check patient:
– If patient awake and alert, monitor patient and call physician
– Pt with symptomatic or unstable VT or SVT cardioverted
immediately.
– If vitals signs stable and VT is persistent or recurrent after
cardioversion, Amiodarone 150mg over 10min should be
given, other drugs may be used like procainamide,lignocaine
or sotalol.
– Pulseless VT requires immediate cardioversion/defibrillation
and CPR. (If patient has no vital signs, call code and start
CPR
» Defibrillate)

56. Ventricular Rhythms
Ventricular Fibrillation
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
0 Chaotic None NA None

57. Ventricular Rhythms
• Ventricular Fibrillation
– No discernable p-waves
– No regularity
– Unable to determine rate
– Multiple irritable foci within the ventricles all firing
simultaneously
– May be coarse or fine
– This is a deadly rhythm
• Patient will have no pulse
• Call a code and begin CPR
• Survival is best if defbrillation occcurs within 3-5 min

58. Asystole
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
None None None None None

59. Asystole
• No p-waves
• No regularity
• No Rate
• This rhythm is associated with death
– Check patient and leads
– No pulse
• Begin CPR

60. Heart Block
First Degree Heart Block
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.)
Norm. Regular
Before each QRS,
Identical
> .20 <.12

61. Heart Block
– First Degree Heart Block
• P-wave for every QRS
• Rhythm is regular
• Rate may vary
• Av Node hold each impulse longer than normal
before conducting normally through the ventricles
• Prolonged PR interval
– Looks just like normal sinus rhythm
Cuases- increased vagal tone, digitalis toxicity, inferior wall
MI and myocarditis.
-Usually asymptomatic and rarely require T/t.
-Elimination of drugs that slows AV conduction or clinical
factors that enhance vagal tone can reverse 1st degree
block.

62. Heart Block
Second Degree Heart Block
Mobitz Type I (Wenckebach)
Heart
Rate
Rhythm P Wave
PR Interval
(sec.)
QRS
(Sec.
)
Norm.
can be
slow
Irregular
Present but some
not followed by
QRS
Progressively
longer
<.12

63. Heart Block
• Second Degree Heart Block
• Mobitz Type I (Wenckebach)
– Some p-waves are not followed by QRS complexes
– Rhythm is irregular
• R-R interval is in a pattern of grouped beating
– Rate 60-100 bpm
– Intermittent Block at the AV Node
• Progressively prolonged p-r interval until a QRS is blocked
completely

64. Heart Block
Second Degree Heart Block
Mobitz Type II (Classical)
Heart
Rate
Rhythm P Wave
PR
Interval
(sec.)
QRS
(Sec.)
Usually
slow
Regular
or
irregular
2 3 or 4 before each
QRS, Identical
.12 - .20
<.12
depends

65. Heart Block
• Second Degree Heart Block
• Mobitz Type II (Classical)
– More p-waves than QRS complexes
– Rhythm is irregular
– Atrial rate 60-100 bpm; Ventricular rate 30-100 bpm
(depending on the ratio on conduction)
– Intermittent block at the AV node
• AV node normally conducts some beats while blocking others
• Mobitz type II block has high rate of progression to 3rd
degree heart block. A cardiac pacemaker is mandatory in this
situation.

66. Heart Block
Third Degree Heart Block
(Complete)
Heart
Rate
Rhythm P Wave
PR
Interval
(sec.)
QRS
(Sec.)
30 –
60
Regular
Present but no
correlation to QRS
may be hidden
Varies
<.12
depends

67. Heart Block
• Third Degree Heart Block (Complete)
– There are more p-waves than QRS
complexes
– Both P-P and R-R intervals are regular
– Atrial rate within normal range; Ventricular
rate between 20-60 bpm
– The block at the AV node is complete
• There is no relationship between the p-waves and
QRS complexes.
• Cardiac pacing is require in cases of 3rd degree
block

68. • Anaesthetic management
-Previous placement of a transvenous pacemacker or
availability of of transcutaneous cardiac pacing is required
before an anesthetic is administered for insertion of
permanent cardiac pacemaker ,
-Isoproterenol may be required to maintain acceptable HR
and acts as “chemical pacemaker” untill the artificial
pacemaker is functional

69. MODALITIES FOR TREATMENT OF
ARRHYTHMIA
• Antiarrhythmic drugs
. All such drugs may aggravate or produce
arrhythmias and they may also depress
ventricular contractility and must, therefore, be
used with caution.
• They are classified according to their effect on
the action potential (Vaughan Williams'
classification)

71. Drugs affecting different parts of the
heart

72. Management of Arrythmia’s
• ECG and rhythm information
• should be interpreted within the context of
total patient assessment
• Providers must evaluate
• Patient’s symptoms
• Clinical signs
• Ventilation, oxygenation, heart rate, blood
pressure, signs of inadequate organ perfusion

73. • In both unstable and symptomatic cases
• Provider must make an assessment whether
it is the arrhythmia that is causing the patient
to be unstable
• Patient in septic shock with sinus
tachycardia 140 / min is unstable
• Electric cardioversion will not improve this
patient’s condition

74. • If patient with severe hypoxemia becomes
hypotensive and develops bradycardia
• Bradycardia is not the primary cause of
instability
• Treating the bradycardia without treating
the hypoxemia is unlikely to improve the
patient’s condition

77. Supraventricular Tachycardia
• (Supraventricular - a rhythm process in which
the ventricles are activated from the atria or
AV node/His bundle region)
• Refers to supraventricular tachycardia other
than afib, aflutter and MAT
• Occurs in 35 per 100,000 person-years
• Usually due to reentry—AVNRT or AVRT

78. • QRS typically narrow (in absence of bundle
branch block); thus, also termed narrow QRS
tachycardia
• Usually paroxysmal, i.e, starting and stopping
abruptly; called PSVT
• Aetiology should be considered before
therapy is instituted

79. Vagal maneuver
• Valsalva maneuver or carotid sinus massage
• Terminate up to 25% of PSVTs
• For other SVTs
• May transiently slow the ventricular rate
• Potentially assist rhythm diagnosis but will
not usually terminate such arrhythmias

80. Adenosine ( if regular)
• If PSVT does not respond to vagal maneuvers
• Give 6 mg of IV adenosine as a rapid IV push
through antecubital vein followed by a 20 mL
saline flush
• If the rhythm does not convert within 1 to 2
minutes
• Give a 12 mg rapid IV push using the method
above

81. Narrow-complex irregular
tachycardia
• Atrial fibrillation with uncontrolled
ventricular response
• MAT
• sinus rhythm/tachycardia with frequent atrial
premature beats

82. Rate Control
• Unstable patients
• Prompt electric cardioversion
• Stable patients
• Ventricular rate control as directed by
patient symptoms
• IV nondihydropyridine calcium channel
blockers
Diltiazem are drugs of choice for acute rate
control in most individuals with atrial
fibrillation and rapid ventricular rate

83. Ventricular arrhythmias
• Non-sustained ventricular
arrhythmias
- routinely seen in the absence of cardiac
disease- may not require drug therapy in the
perioperative period.
- Conversely, in patients with structural heart
disease, these non-sustained rhythms do
predict subsequent life-threatening ventricular
arrhythmias.

84. NSVT after - cardiopulmonary bypass, unstable
patients with marginal perfusion may
deteriorate with recurrent episodes of NSVT
may benefit from suppression with lidocaine or
beta blockade.
repletion of post-bypass hypomagnesaemia
(MgCl2 2 g i.v.) reduces the incidence of NSVT
after cardiac surgery.

85. Sustained VT
• two categories: monomorphic and
polymorphic.
• monomorphic VT - the amplitude of the QRS
complex remains constant
• polymorphic ventricular tachycardia - the QRS
morphology continually changes.

86. Therapy for monomorphic wide
complex tachycardia
• If the etiology of the rhythm cannot be
determined
• QRS monomorphic, regular
• IV adenosine is relatively safe for both
treatment and diagnosis
• However, adenosine should not be given for
unstable or irregular or polymorphic wide
complex tachycardias
• • It may cause degeneration of the
arrhythmia to VF

87. • If the wide-complex tachycardia proves to be
SVT with aberrancy
• transiently slowed or converted by
adenosine to sinus rhythm
• If due to VT there will be no effect on rhythm
(except in rare cases of idiopathic VT)
• When adenosine is given for undifferentiated
wide complex tachycardia
• Defibrillator should be available

88. For patients who are stable with
likely VT
• IV antiarrhythmic drugs or elective
cardioversion is the preferred treatment
strategy
• Amiodarone
• Procainamide
• Sotalol
• Procainamide and sotalol should be avoided
in patients with prolonged QT, CHF

89. Wide-complex irregular
rhythm
• Should be considered preexcited atrial
fibrillation
• Expert consultation is advised
• Avoid AV nodal blocking agents
• adenosine, calcium channel blockers,
digoxin, and possibly β-blockers

90. Polymorphic (Irregular) VT
• First step
• Stop medications known to prolong the QT
interval
• Correct electrolyte imbalance
• Acute precipitants: drug overdose or
poisoning

91. Prolong QT interval (Torsades de
pointes)
• The management of torsades de pointes
differs markedly from other forms of VT, and
includes
• i.v. magnesium sulfate (2±4 g),
• repleting potassium,
• and manoeuvres aimed at increasing the heart
rate (atropine, isoprenolol or temporary atrial
or ventricular pacing).
• Haemodynamic collapse with torsades
requires asynchronous DC counter shocks