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Flashcards in CVD - Arrhythmias Deck (18):

Main presentations of:
- Tachyarrhythmias
- Bradyarrhythmias
- Combination

–Tachyarrhythmias: Palpitations
–Bradyarrhythmias: Syncope/presyncope
–Combination: Palpitations and syncope/presyncope


What should you ask in Hx of palpitations?

–Character (rapid/more forceful/missed beats)
–How rapid
–Tap out rhythm (regular/irregular)
–Onset and offset (sudden or gradual)
–Precipitants (eg. Caffeine, stressful situation, lying in quiet room on left side) or relieving factors
–Associated symptoms: Chest pain, dyspnoea, syncope/presyncope


Ix of palpitations

•ECG needed in all patients
•Aim to document exact cardiac rhythm at time of palpitations
•Prolonged ECG monitoring
–Holter monitor (24 hours)
–Event recorder (7 days)
–Loop recorder (months-years)
–Look for underlying structural heart disease
•Special tests: electrophysiology study


Compare the differences b/w holter monitor, event recorder & loop recorder as a monitoring device for arrhythmia

•Holter monitor
–24 hours
–Records every beat, patient keeps symptom diary
–Susceptible to artifact

•Event recorder
–Records when triggered by patient
–20 min memory pre trigger
–Susceptible to artifact

•Loop recorder
–Up to 3 years
–Requires small operation, leaves scar


What are 2 Mx decisions should you make for AF?

Decision 1: rhythm vs. rate control
- Rhythm: sotalol, flecainide, amiodarone
- rate: beta blockers, Ca2+ channel blockers, digoxin

Decision 2: stroke risk (CHADSVASc2) vs. bleeding risk (HAS BLED)
- aspirin
- anticoagulation (warfarin, NOAC)


Briefly describe catheter ablation for AF. What is a common ablation site?

Catheter ablation aims to maintain sinus rhythm by preventing signals propagating from AF origin sites

Common ablation sites for AF are around the pulmonary veins - “pulmonary vein isolation” procedure


Supraventricular tachycardia
- 90% of cause
- common structural involvement

90% due to “re-entrant” circuits within the heart
–Most common AV nodal re-entry tachycardia
–Also Wolff-Parkinson White syndrome

Almost all SVTs involve the AV node in the pathway
–The AV node is therefore targeted with treatments in order to interrupt the circuit


Mx of SVT

1. Vagal manoeuvres

2. Adenosine (When it is administered intravenously, adenosine causes transient heart block in the atrioventricular (AV) node)
•Warn patient of flushing/feeling terrible for a few seconds (half life


What is a delta wave & when do you see it?

slurred upstroke of QRS complex (“delta wave”)

Seen in Wolff-Parkinson White pattern. indicates a large “macro” re-entrant pathway bypassing the AV node


What does Broad complex regular tachycardia indicate?

ventricular tachycardia until proven otherwise


Rx of ventricular tachycardia

•If haemodynamically unstable
–Requires immediate DC reversion

•If sustained and haemodynamically stable
–May try pharmacological reversion with amiodarone
–Sedate patient to administer DC shock


Definition of syncope

•Loss of consciousness, self-limited
•Onset relatively rapid
•Leads to fall
•Recovery complete, rapid, spontaneous


When someone has a syncope, what should you look for in ECG?

–Signs of sinus node disease: Sinus bradycardia, pauses
–Signs of AV conduction block: First/2nd/3rd degree
–Rarely: Wolff-Parkinson White pattern, long QT interval


Describe 1st degree AV block

PR interval of >0.2 second
Every P wave followed by a QRS complex


Describe 2nd degree AV block
- Mobitz type I (Wenckebach block)
- Mobitz type II
- High-grade AV block

Mobitz type I (Wenckebach block)
- Progressive lengthening of PR interval & shortening of RR interval until a P wave is blocked
- PR interval after blocked beat is shorter than preceding PR interval
(gradually increasing PR till a disappeared QRS wave after P)

Mobitz type II
- Intermittently blocked P waves (no following QRS)
- PR interval on conducted beats is constant

High-grade AV block
- conduction ratio of 3:1 or more
- PR interval of conducted beats is constant


Describe 3rd degree AV block

- dissociation of atrial & ventricular activity
- atrial rate is faster than ventricular rate, which is of junctional or ventricular origin


Indications for PPM insertion

–Sinus node dysfunction
•Symptomatic sinus bradycardia
•Sinus pauses >2s (day) or 2.5s (night)

–Symptomatic 2nd or 3rd degree AV block

–Intermittent 3rd degree AV block


Describe combined tachybradyarrhythmias
- Rx
- Ix

• Px: palpitations + syncopal episodes
•Most frequently sick sinus syndrome with “tachy-brady syndrome”
•Episodes of sinus bradycardia or pauses, and other episodes of atrial fibrillation with rapid heart rates
•Difficult to treat without a pacemaker (can’t control tachycardias without worsening bradycardias)

•If concerned, do not start AV nodal blocking agents
•Wait for results of Holter monitor

•Once pacemaker implanted, can use AV node blocking agents to control rapid heart rates (beta or calcium channel blockers)

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