Atrial Fibrilation Flashcards
What is it?
Who is it more common in?
Supraventricular tachyarhythmia
With CHAOTIC and irregular conduction of depolarisation through the atrium and then the ventricles.
Men
Causes by PIRATES:
What does it stand for?
Pulmonary IHD Rheumatic Disease and mitral stenosis Alcohol, smoking and caffeine Thyrotoxicosis Electrolyte abnormalities Sugar (DM) and Sepsis
Read the following for more info:
Alcohol consumption is a known cause of AFib. In the short term, alcohol disrupts your natural pacemaker, or the electric circuitry in the heart that keeps a normal, steady heartbeat. Disruption of steady electrical signals in the heart can lead to an irregular and fast heartbeat.
Smoking is associated with elevated blood pressure and heart rate which also are risk factors for atrial fibrillation
Drinking too much caffeine could raise your blood pressure and increase your heart rate (which might trigger atrial fibrillation).
Causes by PIRATES:
(P)ulmonary:
- Why do lung diseases cause AF?
- List a few? - 5
IHD - list a few? - 3
So can high levels of carbon dioxide (CO2) in the blood, a condition common in late-stage COPD. Upper respiratory infections and bronchitis are common in COPD. This can cause the lung’s arteries to narrow or become blocked, a condition called pulmonary hypertension, which can lead to AFib.
PE Pleural effusion COPD Lung cancer Pneumonia
Acute MI
HTN
HF
Causes by PIRATES:
Valve stenosis - how does this cause AF?
Electrolyte abnormalities - potassium, magnesium
Heart valve stenosis is also linked to a higher risk for atrial fibrillation. For example, mitral valve stenosis results in an obstruction to blood flow from the left atrium to the left ventricle causing the pressure to increase in the left atrium. As a result, the heart enlarges, and atrial fibrillation can occur.
Hypokalaemia
Hypomagnesemia
Classification:
Acute AF
Onset within 48 hrs either new or recurrent episode
Classification:
Chronic AF sub-classified as:
- Paroxysmal AF - what is it?
- Persistent AF - what it is? - 2
- Permanent AF
Usually self terminates < 7 days
Lasts > 7 days
< 7 days but requires cardioversion - a medical procedure by which an abnormally fast heart rate (tachycardia) or other cardiac arrhythmia is converted to a normal rhythm using electricity or drugs.
Unresolved by cardioversion
Symptoms:
- What is the patient’s main symptom?
- Head
- Lungs
- What type of pain do they have?
- 20% will be asymptomatic.
Signs:
- Pulse
- BP
Symptoms of complications - 2
Palpitations Syncope SOB Angina - central crushing chest pain Asymptomatic
Tachycardia, irregularly irregular and apical pulse may be faster than radial
Hypotension
Stroke/TIA Pulmonary oedema (acute HF)
Investigations:
ECG:
What is absent and what replaces it?
What is AF known as if HR>100bpm?
What happens if there is prolonged epodes of this?
What should be used to record if paroxysmal AF suspected? - 2
P waves replaced with small irregular F waves
Rapid ventricular response or fast AF
Transient ischaemic changes such as ST-elevation/depression
Event recorders such as loop recorders, Holter monitors etc.
The irregular rhythm in addition to the absence of any clear P waves is typical of atrial fibrillation.
Investigations:
Bloods - why do …?
FBC
U&E
TSH
LFT and coag
Anaemia which ay exacerbate HF
Looking for cause
Looking for cause
To check how they will deal with warfarin if they need it
Investigations:
Why do you do a trans-thoracic echo and CXR?
Cardiac causes and complications
May show signs of HF
Management:
What are 2 ways to manage AF?
What score is used to determine the risk of a VTE and what score is used to work out the risk of haemorrhage?
Rate or rhythm control
CHADVASC score and HASBLED score - they are used in combination
Reducing the risk of thromboembolism especially stroke with chadvasc score > 1 in men and > 2 in women.
If the score 0 for men or 1 for women, then no Rx is given OR just aspirin.
Management:
Drugs to prevent clots
Direct oral anticoags (DOAC)
Warfarin
Rate control in AF:
1st line:
Beta-blockers - 2 examples - M, B
Rate-limiting calcium channel blockers - 2 examples
Digoxin is a monotherapy to control the rate. What feature of a patients lifestyle must be present for it to be prescribed?
Metoprolol, bisoprolol
Verapamil, diltiazem
They have to be sedentary - so maybe someone who is bed-bound.
Rate control in AF:
2nd line - you combine 2 of the following ………
b-blockers, diltiazem (CCB) and/or digoxin
Rate control in AF:
‘Pill in the pocket’ is used in paroxysmal AF. What does this mean?
What other criteria does the patient have to meet to get the above? - 4
What if AF episodes are very infrequent?
PRN stall or flecainide (pill in the pocket) - stops the arrhythmia
Infrequent episodes.
Understand how and when to take it.
No structural (LVF, valvular) or ischaemic heart disease.
SBP >100 and HR >70.
No Rx
Rhythm control:
When is this initiated?
Who gets it?
If rate control has failed or as an alternative 1st line treatment
New onset AF
AF with reversible causes
AF leading to HF
Patients who it is considered more suitable for (e.g. young patients who are active)
Rhythm control:
What is available?
Electrical cardioversion
Pharmacological cardioversion
Electrical cardioversion:
When is this the preferred choice?
What should be given before starting this to prevent clots?
Haemodynamically unstable - SBP<90, syncope, acute HF, MI
THE PERSON IS BASICALLY ON THEIR DEATH BED - YOU SEE THIS IN MOVIES ALL THE TIME!!
Anticoagulation
Pharmacological cardioversion:
Indications
How is it administered?
What meds are given if there is no structural heart disease? - 2
What antiarrhythmic drug is given if there are structural or ischaemic HD? - A
Why is this med given through a central line?
What should be given before starting this to prevent clots?
Symptoms milder
Situation less urgent
IV - bolus then infusion (maintenance)
flecainide or propafenone
Amiodarone
Risk of thrombophlebitis if done peripherally
Anticoags
What drugs should be given if cardioversion is elective?
What is given for long term rhythm control post cardioversion in persistent AF
Give thromboprophylaxis 3 wks before
Amiodarone 4 wks pre and up to 12 months post
b-blockers
Dronedarone, amiodarone
Catheter ablation:
What is it?
Indications
Methods
A minimally invasive procedure
A flexible thin tube (catheter) through the blood vessels to your heart to ablate (stop) abnormal electrical pathways (signals) in the heart tissue.
If refractory or has contraindications to medical therapy
Younger patients to avoid lifetime of meds
Radiofrequency
Cyrotherapy
Microwave
What does ablate and pace mean?
When is it considered?
Ablation of the AV node followed by pacemaker insertion - can be considered in permanent AF with LV dysfunction.
Complications of AF
Stroke (5x more likely)
Acute HF and pulmonary oedema
Cardiomyopathy and HF
