Atrial Fibrilation Flashcards
What is AF?
Chaotic and disorganised atrial activity resulting in irregularly irregular heat beat
What is the most common cause of AF?
Ectopic foci in the muscle sleeves in the atria of the pulmonary veins
AF is the most common sustained arrythmia. True or false?
True
All AF is symptomatic. True or false?
False
How is AF terminated?
1) Pharmacological cardioversion with anti-arrythmic drugs is 30% effective
2) Direct current cardioversion (DCCV) is 90% effective
What antiarrhythmic drugs can be used to terminate AF?
Flecainide, Sotalol, Amiodarone
What is paroxysmal AF?
AF lasting less than 48 hours but often recurring
What is persistent AF?
AF lasting more than 48 hours which can still be cardioverted to NSR
What is permanent AF?
AF which cannot be restored to NSR by pharmacological and non pharmacological methods
What are the associated diseases which can lead to AF?
Hypertension, CCF, CAD, Obesity, Thyroid disease, Familial, Septicaemia, COPD, Pneumonia, Alcohol abuse, Congenital heart disease, Cardiac srgery, Pericarditis, Tumours.
What is sick sinus syndrome?
Tachy brady syndrome found in older people
Which group of people with AF are at the highest risk of stroke?
Those with cardiac valve disease
What is idiopathic AF?
Absence of any heart disease and no evidence of ventricular dysfunction. Could be genetic or familial.
Its the diagnosis of exclusion. Have a high risk of stroke
What are the common symptoms of AF?
Palpitations, presyncope, syncope, dyspnoea, fatigue, chest pain, sweatiness.
Some people are assymptomatic.
If AF is paroxysmal, are symptoms worse at onset or delayed?
At onset due to associated anxiety
What is hypertensive heart disease?
AF and left ventricular hypertrophy
What is the mechanism of AF?
Multiple wavelets of re-entry or ectopic focus around the pulmonary veins
What are the ECG findings for AF?
Atrial rate >300bpm
Irregularly irregular rhythm
Absent P waves- just disorganised atrial activity
Ventricular rate is variable
In AF, the ventricular rate is variable. What is it dependent on?
AV node conduction properties
Sympathetic and parasympathetic tone
Presence of drugs acting on the AV node
What is the management for AF with a slow ventricular rate?
Pacemaker as you cannot give beta blockers for AF as it may lead to heart block
What is pseudo-regularisation?
AF with a fast ventricular rate therefore you cannot appreciate the irregularly irregular heart rate
What are the complications of AF?
Heart failure and reduced cardiac output => low BP
What are the 2 branches to AF management and which is better?
1) Rhythm control- aim to maintain sinus rhythm
2) Rate control- Accept AF but aim to control ventricular rate. (higher risk of thromboembolism and stroke)
Decision is not outcome driven as there is no evidence to show one is better. Treatment is symptom driven
What is involved in AF rate control?
Pharmacological therapy to slow down AV node conduction.
Digoxin, beta blockers, verapamil/diltiazam