Atrial Fibrillation Flashcards
Which of the following is not a common complication of atrial fibrillation?
A Acute ischaemic stroke B Cardiac failure C Pulmonary embolism D Acute mesenteric ischaemia E Acute limb ischaemia
Pulmonary embolism may be a cause of, but not commonly a direct consequence of, atrial fibrillation.
Patients with atrial fibrillation are at risk of developing blood clots within the left atrial appendage. Stasis of blood promotes thrombus formation.
Embolisation to the brain may cause cerebral ischaemia. Embolisation to the limbs may cause acute limb ischaemia and to the bowel will cause acute mesenteric ischaemia. Patients with atrial fibrillation are also at risk of developing cardiac failure. There is a temporal relationship between atrial fibrillation and cardiac failure related to a number of shared risk factors and neurohormonal dysregulation that occurs in both conditions.
A 79-year-old female presents to the acute medical unit with a one-year history of dizzy spells. She does not complain of palpitations or chest pain but does get increasingly breathless on minimal exertion. She has a past medical history of hypertension and her only medication is ramipril. On examination, she has an irregular pulse at 130 bpm. An ECG is performed, which reveals an irregularly irregular rhythm and an absence of P waves. Her CHA2DS2-VASc score is 3.
What is the most appropriate initial treatment option from the choices below?
A Apixaban and bisoprolol B Elective DC cardioversion C Heparin and amiodarone D Dabigatran monotherapy E Flecainide monotherapy
In patients with persistent AF the recommended management is rate control drugs (e.g. beta-blockers, calcium channel blockers) and anti-coagulation according to risk stratification.
A
Older anti-coagulants (e.g. warfarin) are widely used for the prevention of thromboembolism in AF. However, patients should ideally be converted to DOACs - WHY?
Older anti-coagulants (e.g. warfarin) are widely used for the prevention of thromboembolism in AF. However, patients should ideally be converted to DOACs (e.g. apixaban) as they are better tolerated and do not require any monitoring. In the presence of new-onset AF, a DOAC should be offered first-line if advocated by a high CHADS-VASc score. If DOACs are not tolerated or not suitable, a vitamin K antagonist can be given.
In the presence of new-onset AF, a … should be offered first-line if advocated by a high CHADS-VASc score.
In the presence of new-onset AF, a DOAC should be offered first-line if advocated by a high CHADS-VASc score.
The … score is a risk stratification tool used in atrial fibrillation to determine those at greatest risk of cerebrovascular events.
The CHA2DS2-VASc score is a risk stratification tool used in atrial fibrillation to determine those at greatest risk of cerebrovascular events.
NICE NG196 recommends anticoagulation (DOAC) in all patients with a score ≥ … taking into account bleeding risk. Anticoagulation should be considered in men with a score of 1. In women with a score of 1 due to gender, NICE does not consider this an indication for treatment.
NICE NG196 recommends anticoagulation (DOAC) in all patients with a score ≥ 2 taking into account bleeding risk. Anticoagulation should be considered in men with a score of 1. In women with a score of 1 due to gender, NICE does not consider this an indication for treatment.
A variety of non-cardiac causes may precipitate atrial fibrillation.
Respiratory: COPD, pneumonia, pulmonary emoblism
Endocrine: hyperthyroidism, diabetes mellitus
Acute infection
Electrolyte disturbances: hypokalaemia, hypomagnesaemia, hyponatraemia
Drugs: bronchodilators, thyroxine
Lifestyle factors: alcohol, excessive caffeine, obesity
Traditionally, causes of AF are divided into cardiac and non-cardiac. It is most commonly associated with hypertension, coronary artery disease and myocardial infarction.
Cardiac causes?
Hypertension Ischaemic heart disease Valvular disease (e.g. rheumatic heart disease) Myocardial infarction Cardiomyopathy
One of the major complications of AF is..
One of the major complications of AF is the formation of a thrombus (i.e. blood clot) within the atria.
Symptoms AF
Asymptomatic Palpitations Shortness of breath Angina Presyncope Lethargy
AF signs
Irregularly irregular pulse
Absent ‘a’ wave on JVP: corresponds to atrial contraction
Tachycardia
Hypotension
Features of heart failure: bibasal crackles, raised JVP, peripheral oedem
Causes of an irregularly irregular pulse include:
Atrial fibrillation
Premature beats (i.e. ectopics)
Atrial flutter with variable block
Other atrial tachyarrhythmias (e.g. multi-focal atrial tachycardia)
If AF is suspected, a formal diagnosis is made by performing a 12-lead ECG. Alternatively, if paroxysmal AF is suspected then ambulatory ECG monitoring can be requested:
24-hour monitoring: for asymptomatic episodes or symptomatic episodes < 24 hours apart
48-hour monitoring (occasionally completed)
7-day monitoring: longer period of monitoring if symptomatic episodes are infrequent
Loop recorder: a small device placed surgically under the skin. Provides continuous monitoring up to 3 years.
New technology: new software is available on smartwatches and phones that monitor for AF
Atrial fibrillation is characterised by …
Atrial fibrillation is characterised by an irregularly irregular rhythm, absent P waves and fibrillating baseline.
Both transthoracic echocardiography (TTE) and transoesophageal echocardiography (TOE) and important in the work-up and management of AF:
TTE: basic echo that involves imaging of the heart via the chest wall with an ultrasound probe
TOE: invasive echo that involves the insertion of an endoscope into the oesophagus to look at the heart with an ultrasound internally