Arrhythmia: Atrial fibrilation (Complete) Flashcards
Define atrial fibrilation
Type of arrythmia characterised by rapid, uncoordinated atrial contraction (around 300-600 bpm).
(Delay in the AV node means that only some of the atrial impulses reach the ventricles resulting in irregular ventricular response).
Atrial fibrilation is most common at which ages?
At advancing ages >80 years
What are cardiac causes of atrial fibrilation? (4)
Ischaemic heart disease
Hypertension
Rheumatic heart disease (mainly the mitral valve)
Myocarditis
What are non-cardiac causes of atrial fibrilation? (6)
Dehydration
Electrolyte disturbances (E.g. hypokalaemia, hypomagnesaemia)
Endocrine causes (e.g. hyperthyroidism)
Infective causes (e.g. sepsis)
Pulmonary causes (e.g. PE or pneumonia)
Environmental toxins (e.g. alcohol abuse)
What are the four main types of atrial fibrilation?
Acute AF: Lasts < 48 hours
Paroxysmal AF: Lasts < 7 days and is intermittent
Persistent AF: Lasts > 7 days but can be cardioverted
Permament AF: Lasts > 7 days and cannot be cardioverted
What are the main symptoms of atrial fibrilation?
Palpitations (pounding, fluttering or beating irregularly)
Chest pain (anginal chest pain if they have ischaemic heart disease)
Shortness of breath (due to AF related cardiomyopathy)
Dizziness
What are the main signs of atrial fibrilation? (4)
Irregularly irregular pulse
Single waveform on JVP
Variable intensity of heart sounds on auscultation
Features suggestive of HF due to AF
What presentation of AF indicates the need for immediate treatment?
If there is AF alongside ventricular tacchycardia (known as Fast AF)
What investigations should be conducted for patients suspected of having AF? (5)
Bedside:
ECG: No p-waves
Bloods:
FBC
Serum magnaesium
U&Es: Pottasium
Calcium
TFT
Imaging:
Echocardiogram (rule out other cardiac pathologies or identify causes)
What is the management plan for patients with Fast AF? (3)
ABCDE approach
If haemodynamically unstable (e.g. shock, syncope, chest pain, pulmonary oedema): Immediate DC cardioversion
Treat reversible causes:
Infection: ABs
Dehydration: IV fluids
Electrolyte imbalance: Replace electrolytes
When is DC cardioversion offered in management of AF?
If patient is haemodynamically unstable
If patient has an acute new AF which has presented <48 hours then can be cardioverted with sedation
What is the main management plan for AF?
Rate control:
Beta-blocker (e.g. bispropolol)
Rate-limitting calcium-channel blocker (e.g. dilitazem).
N.B. Do not offer in patients with reversible causes, have HF secondary to AF or new-onset AF.
Rhythm control: Used for patients with longstanding history of AF or if AF > 48 hours
Electrical cardioversion
Pharamcological: (e.g. Flecanide, amiodarone [lots of side-effects], soltalol).
Anticoagulation
DOAC or Warfarin
Based off of risk (CHA2DS2-VASc score) and bleeding risk (HASBLED score)
What is the main beta-blocker used in treatment of AF? What are some of the contraindictions for using this medication?
Bispropolol
Contraindictions:
COPD and Asthma
Hypotension (will drop the BP)
Rate-limitting Calcium-channel blockers used in treatment of AF is contraindicted in which type of patient? (2)
Patients with HF
Avoided in young patients (due to increase in cardiac mortality)
What medication can be given to patients to treat AF if beta-blockers or CCB are contraindicted?
Digoxin (Outdated medication used to be 1st line)
(Useful for hypotensive patients or those with HF)
N.B. Avoid in younger patients as it increases cardica mortality
What scoring system is used to determine risk of embolism/stroke in patients with AF?
CHA2DS2-VASc score
Score of 2 or more
(Score of 1 in males you can consider but not 1 in females as the point is only due to their sex)
What scoring system is used to measure bleeding risk in patients when considering anticoagulant treatment?
HAS-BLED or ORBIT score
What ECG changes are characteristic of digoxin treatment?
Down-sloping ST deppresion
