Abnormal Heart Rhytm

Question 1

What is wrong with this ecg

Answer 1

Ventricular tachycardia
(Has a wide complex so if tachycardia as well chances are 90% that it is VT) normal 3-5 small boxes

Question 2

Other causes of wide complex tachycardia

Answer 2

Question 3

Difference between VT and LBBB

Answer 3

Question 4

VT p waves

Answer 4

Usually AV dissociation present but seldom visible on ECG

Question 5

Differentials for wide complex tachycardia

Answer 5

Ventricular Tachycardia (1st guess)
Supraventricular tachycardia with BBB (2nd guess)
Pre-excited tachycardia over an accessory
pathway (Antidromic AVRT)
Ventricular paced rhythm

Question 6

Animation of wide complex tachycardia

Answer 6

Question 7

Must look for if wide complex tachycardia (patient may present with the following as well)

Answer 7

BBB (look in v1 and v6)
WPW (delta waves)
MI (q waves present)

Question 8

Narrow complex regular tachycardia differential

Answer 8

Sinus tachycardia
Atrial flutter
AVJRT (AVNRT, AVRT)👉🏻supraventricular tachycardias
Atrial tachycardia
Junctional ectopic tachycardia

Question 9

Tachyarrhytmia

Answer 9

Question 10

Treatment of patient coming in with tachycardia

Answer 10

Immediate synchronized DC cardioversion is the most
effective

Amiodarone has a low efficacy in terminating VT in the acute
setting (20-30%) and may cause hypotension
Never give verapamil or adenosine in patients with a wide
complex tachycardia

Remember: Patients with VT can be haemodynamically stable

Question 11

VT in younger patients

Answer 11

Cause can be idiopathic

Question 12

VT examinations

Answer 12

Structural heart diseases
Systemic diseases (sarcoidosis)
Correct electrolytes

Question 13

Treatment longterm for VT patients

Answer 13

VT due to structural heart disease:
– Commence anti-arrhythmic drug therapy (Beta-
blocker and Amiodarone)
– Refer for implantable cardioverter defibrillator
(ICD)
– VT ablation for recurrent ICD shocks
– Tx underling cause - Immunosuppressive
treatment (sarcoidosis)
(cf Idiopathic VT: refer for radiofrequency ablation)

Question 14

Answer 14

Implantable Cardioverter Defibrillator

Question 15

Differential of transient loss of consciousness

Answer 15

Question 16

Taking history after syncope

Answer 16

*Circumstance
pain, prolonged standing, cough, micturition, swallowing, during, exertion
*Prodrome
absent, palpitations, warmth, diaphoresis, sweating, nausea, ringing in the ears,
abdominal pain aura
*During the TLOC
pallor, sweating, cyanosis posturing, jerking
*Postdrome
rapid recovery or fatigue confusion
*Medication
*Family history
*History of cardiac disease

Question 17

Features of different causes of syncope

Answer 17

*Epilepsy
Tongue biting
Tonic clonic movements/head posturing
Confusion after loc
*Vasovagal
Prodrome (sweaty, nausea, light headedness)
Situiational (prolonged standing or sitting)
*Orthostatic
Postural dizziness
*Cardiac syncope
History of structural heart disease
*Exertional syncope
No prodrome, unpredictable
Palpitations at the time of syncope

Question 18

Bradycardia main questions to ask yourself

Answer 18

Is this an AV block (p waves without qrs complexes)
Is this a sinus bardycardia (all p waves has qrs complexes)

Look in the inferior leads to confirm this(v1,v2 and avf)

Question 19

Heartblock features

Answer 19

More p waves than qrs complexes
Regular rhytm (look at qrs to see this)
No association between p waves and qrs

Question 20

Mechanism behind bradycardias

Answer 20

*Impulse generation (Sinus node problem)
Sinus bradycardia
Sinus arrest
Tachy-brady syndrome
Sino-atrial exit block

*Impulse conduction (i.e. AV node or HPS
problem)
1st, 2nd, 3rd degree heart block

Question 21

Causes of sinus node dysfunction

Answer 21

*Intrinsic (intermittent dizziness, syncope)
Sick sinus syndrome

*Extrinsic (“sick” from underling cause)
Hyperkalaemia
Hypothermia
Hypothyroidism
Hypoxia
Hypercarbia
Head injury
Hypervagotonia
Drugs

Question 22

Causes of heart block

Answer 22

• Degenerative (by far the most common)
• Inferior STEMI
• Congenital
• Infiltrative (Sarcoid, Amyloid)
• Drugs (remember digoxin)
• Hyperthyroidism
• Connective tissue diseases
• Aortic root abscess

Question 23

Answer 23

Sinus arrest

Question 24

Heart block degrees

Answer 24

– 1st degree (at average node usually or his pukinje)
– 2nd degree(at av node usually or his purkinje)
• Type 1 Mobitz (Wenckebach)
• 2:1 AV block
• Type 2 Mobitz
– 3rd degree(at his purkinje usually or av node)

Question 25

Narrow qrs heart block

Answer 25

Complete heart block at av junction

Question 26

Clinical features of heart block

Answer 26

• Usually present with intermittent dizziness,
syncope
• Bradycardia – usually 30 – 40 bpm
• Variable first heart sound
• Often high systolic blood pressure
• Cannon a waves (JVP) due to AV dissociation
• Medical emergency

Question 27

Management of patient with heartblock

Answer 27

Exclude reversible causes:
– Hyperkalaemia
– Inferior STEMI (watch and wait)
– Stop offending drugs (combination of B-blocker,
Ca blocker, digoxin)

Rest will require permanent pacing

Question 28

Who do we pace (permanent pacing)

Answer 28

Symptomatic bradycardia, not due to
reversible cause
• 1st, 2nd or 3rd degree AV block
• Sinus dysfunction
Asymptomatic 2nd or 3rd degree AV block
• Exceptions:
• Type Mobitz I 2nd degree AV block age <40yrs

Question 29

Chest leads

Answer 29