AF Flashcards
How do you identify Left Ventricular Hypertrophy on an ECG?
- very tall R waves
- ST depression
- Over 3 leads
What are signature AF ECG landmarks?
Absence of P waves
-Irregularly irregular
What are the three types of AF?
paroxysmal, persistent or permanent
What is paroxysmal AF usually associated with?
normal hearts
What is chronic AF usually associated with?
heart disease
What are the characteristics of sustained AF?
It is facilitated by increased parasympathetic tone.
- decreased refractory periods
- shorter wave lengths
- making it easier for AF to sustain itself
What is the mechanism of AF?
- Atria is firing away rapidly
- muscle layer in atrium is often diseased
- caused by multiple wavelets of re-entry
How do we stop AF?
- electrical cardioversion (technique where deliver high voltage across the atria to reset the rhythm to voltage 0 of action potential)
- anti arrythmatic drugs
What are the characteristics of paroxysmal AF?
- paroxysmal and lasting less than 48 hours
- often recurrent
What are the characteristics of persistent AF?
- an episode of AF lasting more than 48hours, which can still be cardioverted to NSR
- unlikely to spontaneously revert back to NSR
What are the characteristics of permanent AF?
-inability to restore NSR
What are some of the associated diseases/causes of AF?
-hypertension
-congestive heart failure
-CHD
-obesity
Thyroid disease
-Genetic
-cardiac valve disease
What is Lone (idiopathic) AF
Absence of any heart disease and no evidence of ventricular dysfunction
essentially dont know what causes it
What are the symptoms of AF?
- palpitations
- pre syncope
- syncope
- chest pain
- dyspnoea
- sweatiness
- fatigue
- asymptomatic
How does AF look on an ECG?
- fast atrial rate
- irregularly irregular
- absence of P waves
- Presence of f waves
What is the ventricular rate dependant on in AF?
- Av node conduction properties
- sympathetic and parasympathetic tone
- presence of drugs which act on the AV node
What are some abnormal patterns of AF?
Alow VR rate with periods of fast VR. A pacemaker may be needed to allow control of fast VR. It could result in complete heart block
-treat with pacemaker and B blocker
What is pseudo-regularisation AF?
a fake regular heart rate AF
What are some important points to consider about AF?
- decreased diastole leads to reduced CO
- can result in congestive HF especially in diastolic dysfunction
- VR less than 60 suggest AV conduction disease
What are the management options for AF?
- rhythm control or rate control
- anti-coagulation for both approaches if high risk for thromboembolism
- manage risk and symptoms
What are the treatment options to slow down AV node conduction and therefore slow rate in AF ?
digoxin, B blockers, verapamil, diltilazem
-use these drugs alone or in combination
What are the treatment options to revert AF to sinus rhythm?
- antiarrythmatic drugs
- direct current cardioversion
What are the treatment options to maintain normal sinus rhythm?
- anti-arrythmatic drugs
- catheter ablation of atrial focus/ pulmonary veins
- surgery
What are the four classes of antiarrhythmatic drugs?
1, 2, 3 ,4
What is a class 1 anti- arrythmatic drug?
- reducing Na channel current
- Lignocaine, quinidine, felcainide, propadenone
What is a class II ant arrythmatic drug?
- adrenergic antagonists
- propanolol
What is a class III anti arrythmatic drug?
- action potential prolongation
- aminodarone, sotalol, dronedarone
What is a class IV anti arrythmatic drug?
- ca channel antagonists
- verapamil
what puts you at a high risk of thromboembolism?
- valvular heart disease
- age above 75 especially if female
- hypertension
- heart failure
- previous thromboembolism or stroke
- CAD or diabetes and above 50y/old
- Thyrotoxicosis
Should you have any of risk factors for thromboembolic disease then what medication should you be on?
Anticoagulants ie warfarin, rivaroxaban
What are indications for anticoagulation in valvular AF?
-mitral valve disease: Mitral Stenosis and Mitral regurgitation
What are indications for anticoagulation in non valvular AF?
- age above 75
- hypertension
- HF
- previous stoke/thromboembolism
- CAD/DM
- Diabetes
What is indicated by a 1 or 2 on the CHA2DS2-VASc score?
1- anticoagulation should be considered
2-they should be on anticoagulation
when would radiofrequency ablation in AF be used?
- To maintain SR by ablating AF focus
- For rate control by ablation of the AV node to stop fast conduction to the ventricles
What is an atrial flutter?
-regular and regular form of atrial tachycardia
-usually paroxysmal
-sustained by a macro-re-entrant circuit
-circuit is confined to the rigtht atrium
-episodes can last from seconds to years
-chronic atrial flutter usually progresses to atrial fibrillation
May result in thromboembolism
What are the characteristics on an ECG in atrial flutter?
- atrial 300bpm
- ventricular rate usually half that
- saw tooth P wave pattern
- normal QRS
- normal conduction sometimes 2:1
- regular rhythm but may be variable
What are the treatment options for atrial flutter?
-radiofrequency ablation
-pharmacological therapy
-cardioversion
warfarin for thromboembolic prevention
What are the two goals in atrial flutter?
- -Terminate the flutter and prevent recurrence
- Control the ventricular response during the arrhythmia
What are the pharmacological therapies used in AF in aim of?
- slow the Ventricular rate
- restore sinus rhythm
- maintain sinus rhythm once converted
