Arrhythmias Flashcards
Name three types of sinus arrhythmia
- sinus arrhythmia
- sinus tachycardia
- sinus bradycardia
Name three supraventricular tachycardia?
- atrial flutter
- atrial fibrillation
- ectopic atrial tachycardia
What are the two types of supraventricular bradycardia?
- sinus bradycardia
- sinus pauses
Name four ventricular arrhythmias
- premature ventricular complexes
- ventricular tachycardia
- ventricular fibrillation
- asystole
Name three AV node arrhythmias
- AV nodal re-entry tachycardia
- AV re-entry tachycardia
- AV block
State six causes of arrhythmias
- abnormal anatomy
- autonomic nervous system
- metabolic
- inflammation
- drugs
- genetics
State six common symptoms of arrhythmias
- palpitations
- SOB
- dizziness
- pre syncope/syncope
- sudden cardiac death
- angina/heart failure
What investigations can be done on a patient with a suspected arrhythmia?
- 12 lead ECG
- ECHO
- stress ECG
- 24 hour ECG
- event recorder
- electrophysical study
What is a sinus bradycardia and what causes it?
HR<60bpm, physiological (athlete), drugs (beta blocker), ischaemia
How is sinus bradycardia treated?
Atropine in an acute setting, in the case of haemodynamic compromise - pacing
What is sinus tachycardia and what causes it?
HR >100bpm, physiological (fever, anxiety) & drugs
How can sinus tachycardia be treated?
- treat underlying cause
- beta blockers
Describe normal sinus arrhythmia
Variation in heart rate due to reflex changes in vagal tone during respiration, inspiration increases vagal tone & HR
Describe ectopic atrial tachycardia
premature beats are caused by ectopic impulses which result in abnormal P waves - inverted or absent
Is treatment required for ectopic atria tachycardia?
No - avoid excessive caffeine and cigarettes
What causes atrial flutter?
Re-entry due to an area of slowed conduction near the IVC - the atria conduct much more than the ventricles as every 2nd/3rd impulses passes through the AV node to the ventricles
How can atrial flutter be recognised on an ECG?
sawtooth with absent P waves
Describe atrial fibrillation
Multiple chaotic impulses initiated randomly from ectopic sites in the atria. The AV node is unable to conduct all APs leading to reduced conduction to ventricles
How can AF be recognised on an ECG?
no P waves, narrow QRS, irregularly irregular rhythm
In the case of acute supraventricular tachycardias what is the treatment?
- Increase vagal tone by vagal manoeuvres
- Diving Reflex
- Slow AVN conduction by IV adenosine/verapamil
What is the treatment for chronic supraventricular arrhythmias?
- avoid stimulants
- EP study & radio frequency ablation
- beta blockers
- anti- arrhythmic drugs
Describe AV Nodal Re-entrant tachycardia
Accessory pathway between atrium and AV node, rapid but normal QRS complexes are followed immediately by a p wave
Describe AV re-entrant tachycardia
Accessory pathway between atria and ventricles can lead to Wolff Parkinson White Syndrome which has a delta wave
What is the accessory pathway called in WPW syndrome?
Bundle of Kent
What will WPW syndrome look like on an ECG?
- short PR
- delta wave
- long QRS
- T inversion
State some causes of heart block (won’t remember them all)
Ageing, acute MI, myocarditis, infiltrative disease, drugs, calcific aortic valve disease, post-aortic valve surgery, genetics
Describe 1st degree heart block
slowed conduction, PR interval is longer but does not require treatment
Describe 2nd degree heart block
Mobitz type 1 - PR interval increases until a beat drops
Mobitz type 2 - PR is the same but a beat drops every 2/3 beats
Describe third degree heart block
No APs from SA node get to the AV node so P waves without QRS may be seen
What causes premature ventricular contractions?
Structural - LVH & HF
Metabolic - IHB & electrolytes
How can premature ventricular contractions be treated?
Beta blockers & ablation
What causes ventricular tachycardia?
usually significant heart disease, CAD, previous MI
State some rarer causes of VT
- long QT syndrome, Brugada or cardiomyopathy
What are the two types of VT?
Monomorphic & Polymorphic
Describe the difference between mono and poly morphic VT
monomorphic - all QRS look the same & impulses all come from the same place in the heart
polymorphic - all QRS look different & impulses come from different parts of the heart
Give an example of a polymorphic VT
torsades de pointes
What is the treatment for acute VT?
Defibrillation if unstable
Anti-arrhythmic drugs if stable
Correct triggers
What is the long term treatment of VT?
revascularisation
anti arrhythmic drugs
ICD
VT catheter ablation
Define ventricular fibrillation
Chaotic ventricular electrical activity means the heart cannot pump
What is the treatment for VF?
defibrillation or cardiopulmonary resuscitation
What happens in asystole?
There are no ventricular contractions
What effect does AF have on perfusion & CO?
It reduces diastole where the coronary arteries are perfused this leads to ischaemia. It also reduced ventricular filling & cardiac output
What are the three types of AF?
Paroxysmal/episodic
Persistent
Permanent
Describe paroxysmal AF
lasts less than 48 hours, often recurrent
Describe persistent AF
more than 48 hours, can be cardioverted but unlikely to spontaneously revert
Describe permanent AF
inability of treatment to restore NSR
What is the general management for AF?
Rate & Rhythm control
Anti-coagulation
