CVD - Arrhythmias Flashcards
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) •Echocardiogram –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
- Vagal manoeuvres
- 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
- Transient
- 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
