Arrythmia - AF, Bradycardia, Heart block, VF, TDP

Question 1

Arrythmia

• pathophysiology
• presentation

Answer 1

Ectopic pacemaker

Palpitations
SOB
Dizzy => syncope

Question 2

Atrial flutter

• pattern, rate, location, cause
• diagnosis
• management
• complications

Answer 2

Saw tooth

Fast
Supraventricular
Scar tissue causing ectopic

Management
- AC
- rate/rhythm control
-cardioversion/ablation

Strokes

Question 3

Wolff-Parkinson White

• pathophysiology
• presentation
• ECG findings
• management

Answer 3

Accessory bypass pathway outside AVN

Asymptomatic
Acute - SOB, palpitations, chest pain, syncope

Shortened PR - U3ss
Delta wave, wide QRS

Acute
- valsalva => slow HR
- adenosine => block electrical signal
- cardioversion

Prevention
- avoid triggers
-amiodarone/flecanide/soltalol

Definitive - radio/surgical ablation of pathway

Question 4

1st degree HB

• ECG findings
• rhythm, pathophysiology
• causes

Answer 4

PR 5ss+

Regular
AVN delay

Normal
Electrolytes
Myocarditis
Drugs - adenosine, Bb, CCB, digoxin

Question 5

2nd degree HB Wenckebach and Mobitz 2

• ECG findings
• rhythm, pathophysiology

Answer 5

Wenckeback
PR gets progressively longer => QRS dropped
Regularly irregular
AVN => delay in conduction to ventricles

Mobitz 2
PR prolongation is the same => QRS dropped
Regular
Failure of conduction to His-Purkinje
=> HIGH RISK OF ASYSTOLE
-PPM needed

3rd degree
Slow rate, dissociation between P and QRS
=> HIGH RISK OF ASYSTOLE
-PPM needed

Question 6

Ventricular fibrillation
Ventricular tachycardia
-management

Answer 6

Chaotic disorganised electrical activity => no CO

Defibrillation
DC cardioversion + anti-arrythmic drugs

Monomorphic/TDP

No CO => defibrillation
CO but unstable => DC
CO but stable => amiodarone
Maintenance - implantable DF

Question 7

AF types

Answer 7

First detected
Paroxysmal - AF terminates spontaneously, lasts U7 days
Persistent - not self-terminating
Permanent - continuous which cannot be cardioverted

Question 8

AF
-presentation
-investigations

Answer 8

Palpitations
SOB
Chest pain
Irregularly irregular pulse

ECG - fibrillatory waves, no p waves

Question 9

AF
-management

Answer 9

1. Hemodynamically unstable => electrical cardioversion
   -follow peri-arrest tachycardia guidelines
2. Hemodynamically stable => electrical/pharmacological cardioversion electively

Onset U48hrs - rhythm or rate
-Heparin + rhythm control (amiodarone/flecanide or DC shock)
-no need for further AC

Onset 48hrs+ - rate unless the following
-AC + rate control for 3weeks OR TOE (if unstable) done to exclude thrombus
-heparinize + cardiovert (electrical preferred)
-AC continues

Rate unless
-reversible cause
-HF from AF
-U65
-1st presentation
-symptomatic

Medication
Rate control
1st line - Bb/cardiac CCB
2nd line - digoxin

Rhythm control
1st line - amiodarone
2nd line - flecanide, CI in structural/IHD
DC cardioversion to R wave

3. Catheter ablation - if no response/ wish to avoid medication
   -AC 4wks before and after procedure
   -radiofrequency/cryablation does not reduce stroke risk => DOAC?
   0 = 2 months AC
   1+ = long term AC

Complications
-cardiac tamponade
-stroke
-pulmonary vein stenosis

3. Consider AC use
   -CHADSVASC vs ORBIT
   0 - no treatment
   1 - male => consider female => no treatment
   2 - AC

CANNOT USE DOAC IF THERE IS VALVULAR DISEASE => warfarin

Question 10

AF causes

Answer 10

Pulmonary - PE, COPD
IHD, HF
Rheumatic, valvular
Anemia, alcohol, age
Thyroiditis
Electolyte derangements (K, Mg)
Sepsis, sleep apnoea

Question 11

Bradycardia management

Answer 11

Lifethreatening signs
-shock
-syncope
-MI
-HF
=> atropine 500mcg IV

If responding but risk of asystole
-recent asystole
-Mobitz II, HB3 with broad QRS
-ventricular pause 3s+
OR
If no response
-atropine 500mcg IV to MAX 3mg
-Isoprenaline 5mcg/min IV
-adrenaline 2-10mcg/min IV
-transcut pacing
GET HELP!

If responding with no risk of asystole => observe

Question 12

VT
-management

Answer 12

Adverse signs
-shock
-MI
-HF
-syncope
=> immediate cardioversion

If no adverse signs
-amiodarone or lidocaine
Electrical cardioversion if needed
ICD considered

Question 13

SVT
-management

Answer 13

Tachycardias not originating in ventricles

Acute
-valsalva or carotid sinus massage
-IV adenosine - 6mg => 12mg => 18mg
-electrical DC

Prevention
-Bb
-ablation

ADENOSINE CI IN ASTHMA - USE VERAPAMIL

Question 14

TDP
-pathophysiology
-management

Answer 14

Long QT interval
-erythromycin, TCA, antipsychotics,
-hypothermia, hypoCaKMg
-SAH
-amiodarone, sotalol, 1a antiarrythmics

IV MgSO4

Question 15

AC use in AF

Answer 15

CHADSVASC - risk of stroke/TIA from AF clots
0 or 1 if female - no treatment but use TOE to check for valvular heart disease
1 if male or 2+ - AC

ORBIT - risk of bleeds

1st line - DOAC
2nd line - warfarin

If TIA => DOAC immediately
If ischemic stroke due to AF - daily aspirin, AC 2wks later

Question 16

Digoxin
-mechanism of action
-monitoring

Answer 16

Inhibits NaKATPase and stimulates vagus => decreases conduction through AVN, increased cardiac contractility

Narrow therapeutic index - toxicity is possible even within therapeutic range
-levels not monitored regularly except if toxicity suspected
-levels measured within 8-12hrs of last dose

Question 17

Digoxin toxicity
-presentation
-ECG changes
-triggers
-management

Answer 17

General unwell
-tired
-N+V
-anorexia
-confusion
-yellow green vision
Arrythmias
Gynecomastia - as digoxin is a similar shape to estrogen

Scooped out ST depression
Flat inverted T waves
Short QT
Arrythmias - AV block, bradycardia

Hypokalemia - less K => more chances for digoxin to bind to ATPase => increased inhibitory effects
Renal failure
Low Mg, albumin, temp, thyroid
High Ca, Na

Drugs
-anything causing hypokalemia
-drugs that compete for renal excretion - amiodarone, verapamil, diltiazem, spironolactone

Digibind
Correct arrythmias
Monitor K