2. Atrial fibrillation Flashcards
normal BPM
60-100 bpm
atrial fibrillation
most common atrial tachyarrythmia
caused by abnormal and irregular heart rhythm in which electrical signals are generated chaotically throughout the atria
AF symptoms
fast heart rate
irregular
varies in intensity
can be asymptomatic
palpitation
chest discomfort
dizziness
syncope (lack of consciousness)
shortness of breath
lethargy
common causes of AF
CHD
hypertension
treatment for managing symptoms of AF
rate control using beta blockers or calcium channel blockers
rhythm control using electrical or pharmacological approach or ablation (scarring inside of heart to break up electrical signals that cause irregular heartbeats)
stroke pathophysiology
complication of AF
atrial chamber quivers, causes stagnation of blood (partially ejected), blood clot forms, causes stroke
thrombosis
definition and treatment
formation of potentially deadly blood clots that blocks blood supply
arterial/venous
treatment: anticoagulants eg. warfarin
arterial clots
stroke (head)
heart attack (heart)
peripheral arterial clot
venous clots
pulmonary embolism (chest pain, cough, shortness of breath)
deep vein thrombosis (swelling, pain, warmth, purple discolouration)
haemostasis
mechanism that leads to cessation of bleeding from a blood vessel
haemostasis damaged vessel process
vWF mediates platelet adhesion to damaged vessel wall and platelet aggregation
platelets bind to vWF by adhesion, releases thrombin (activation), attracts other platelets, fibrinogen links between activated platelets results in plug (aggregation), mesh of fibrin holds clot together
Coagulation tests
APTT for intrinsic
PT for extrinsic
INR for PT (international normalisation ratio)
natural anticoagulants
protein C
protein S - cofactor for protein C
antithrombin inhibits thrombin and Factor Xa
warfarin
anticoagulant agent
reversible, administer vitamin K
interacts w food and other drugs
acts as an inhibitor of the vitamin K cycle and vitamin K-dependent clotting factors in liver
therapeutic range
most effective range w/o side effects
(within international normalised ratio)
Stroke risk assessment
CHA2DS2-VASc
Bleeding risk assessment
HAS-BLED
to check if safe to give anticoagulant
Blood test BNP normal level in pg/ml
> 100 pg/ml considered high
left ventricular ejection fraction
ejection fraction = stroke volume/end diastolic volume
<50% considered systolic dysfunction
echocardiogram
checks how heart’s chambers and valves are pumping blood through the heart
severity for heart failure classification
new york heart association functional classification of heart failure
breathlessness
caused by fluid in the lungs
cardiac resynchronisation therapy
monitors heart function, shocks heart when needed, prevents sudden cardiac death, like pacemaker, battery 10-12 years
heart failure drug treatment
ace inhibitors, angiotension receptor blocker or angiotensin receptor-neprilysin inhibitor
beta blockers
diuretics
aldosterone antagonist
CCB not recommended
