Atrial Fibrillation Flashcards
What is atrial fibrillation?
It is when the electrical activity within the heart is uncoordinated therefore the atria do not contract in a coordinated way.
Can cause an irregular and abnormally fast HR
The heart has its own pacemaker which sets the rhythm of the heart however in AF there are abnormal eletrical impulses which overrides this pacemaker causing random contractions. The heart is unable to relax properly between beats so the amount of blood pumped out is reduced
What are the signs of AF?
Tachycardia
Irregular heart rate
Signs of heart failure e.g. basal crepitations, raised JVP, syncope
What are the symptoms of AF?
Palpitations, breathlessness, Chest pain, dizziness, fainting.
What are the different types of AF?
Paraoxymal
persistent
Permanent
What are the causes of AF?
Cardiac causes: Rheumatic heart disease, pre excitation syndromes, heart failure
Non-cardiac causes: drugs, acute infection, electrolyte depletion, lung cancer, PE
What is the treatment for AF?
Warfarin
Na+ channel blockers or beta blockers to maintain heart rate - flecainide or sotalol
pacemaker may be fitted
How does warfarin work?
Vitamin K reductase inhibitor. inhibits the synthesis of vitamin K dependent clotting factors - factors ii, vii, ix x
Prevents stroke and reduces clots forming.
What are some complications of AF?
Stroke
Heart Failure
What are some of the risks of warfarin?
Increased risk of bleeding and bruising
What advice should be given to a patient on warfarin?
Avoid grapefruit and cranberry (CYP inhibitors)
Will need regular blood tests to check clotting time (INR and PT time)
Many medications can react with it.
What are the risk factors for AF?
Hypertension, Diabetes Mellitus, Age, Coronary heart disease and prior MI
What are some questions that can be asked to eliminate AF?
Ask about palpitations
changes in HR
Any episodes of breathlessness or dizziness
What would an ECG look like in a patient with AF?
Irregularly irregular rhythm
No P waves
