CVD - Atrial Fibrillation Flashcards
What is CVD
Heart and blood vessel disease related to atherosclerosis
What is atherosclerosis
Condition that develops due to plaque build up in walls of arteries
Leading cause of death globally
Heart attack is
When blood flow to heart is blocked by a blood clot
Causes cardiac muscle to die
What are the two types of stroke
Ischemic stroke
Hemorrhagic stroke
What is ischemic stroke
Most common
When blood vessel to brain gets blocked
Causes brain cells to die
Hemorrhagic stroke is
When blood vessel within brain bursts
Heart failure (congestive) is
Heart is not pumping blood as well as it should
Cardiac Disease can be (2)
Arrhythmia
Heart valve problems
What is arrhythmia
Abnormal rhythm of the heart
Heart valve problems include
Stenosis
Regurgitation
Mitral valve prolapse
What are the different types of arrhythmias
Atrial fibrillation
Ventricular fibrillation
Bradycardia
Tachycardia
Conduction disorders
Premature contraction
What is atrial fibrillation
Upper heart chambers contract irregularly
What is ventricular fibrillation
Disorganised contraction of the lower heart chambers
Conduction disorders are
When the heart does not beat normally
What is the most common cardiac arrhythmias
Atrial fibrillation
Atrial fibrillation causes
Quivering or irregular heartbeat
Multiple reentrant circuits in the atria
What does multiple reentrant circuits in the atria lead to
Blood clots
Stroke
Heart failure
Other heart related complications
Atrial fibrillation can be seen as
Missing P waves
Electrical current does not flow
Av node often cant regulate the chaotic current
Irregular ventricular rate
When the beat is off and the blood supply can be unpredictable
Missing P wave indicates the
Absense of atrial depolarisation
SA node may not start the contraction
Electrical current not flowing in atrial fibrillation is due to
Contractions being rapid and disorganised
What happens as a result of AV node not being able to regulate the chaotic current
Ventricles beats more often
Slow ventricle response is seen as
Long gaps
Small R height
Moderate ventricular response is seen as
Upside down??
Rapid ventricular response is seen as
Close together
Large R height
What are the ways we medically manage atrial fibrillation
Conversion back to normal sinus rhythm
Controlling ventricular rate response
Preventing blood clots
How do we converse back to normal sinus rhythm
Electrical cardioversion
Radiofrequency ablation
Maze procedure
What is electrical cardioversion
Low voltage electric current to reset heart rhythm back to normal sinus rhythm
What is radiofrequency ablation
Radio waves to manage arrhythmias, usually before pacemaker implant
What is maze procedure
Create scar tissue to block abnormal signal, direct electric signal through a controlled path to ventricles
How do we control ventricular rate response
Reducing overly high heart rate
Pharmacologic: Digoxin Beta blockers Calcium channel blockers Anti arrhythmic
What does digoxin do
Slow heart rate at atria to ventricle
Inhibition of sodium potassium ATP
What does Beta blockers do
Slow HR
Antagonists that block the receptors sites for Epi and NE on adrenergic beta receptors of SNS
What do Calcium channel blockers do
Slows HR
Reduce strength of cardiac muscle contraction
Prevent or reduce the opening of channels not allowing Ca++ get into cells
How do we prevent blood clots
Antiplatelets
Anticoagulants
Antithrombotic
What is the effect on exercise response
Rapid irregular ventricular heart rate
Exercise capacity is reduced by 15-20%
Rapid irregular ventricular heart rate is because (during effect on exercise response)
HR is high at any workload
Reduced SV due to limited atrial assistance during diastole
HR response can be affected by comorbid conditions and medications - a smaller increase in heart rate and SBP as exercise increases
When can exercise testing be useful when certain things are considered (each drug)
Digoxin may control ventricular response - diffuse ST effects
Verapamil may mask ischemia and decrease HR response to exercise
Beta blockers may reduce exercise capacity and decrease submaximal and maximal HR and BP
Age predicted HRmax targets are not valid
Irregular ventricular response may make BP determination less precise or more difficult
Verapamil is what type of drug
Calcium channel blocker
When creating an exercise program what should be considered
Variability of the ventricular rate - Intensity should be prescribed with work rate or perceived exertion
Comorbidities are needed in population with AF
Oberve for exertional HYPOtension
What is really important to do during each session
Assess rhythm
What are the short benefits of exercise training in AF (<6months)
Reduced AF burden
Reduced symptom severity
What are the long benefits of exercise training in AF
Increased AF freedom
Reduced symptom severity
What is the FITT requirement for AF
3-5 days per week
<= 95% peak HR
120 to 200 min/wk
Aerobic exercise and/or resistance training
What are the overall potential benefits of AF
Reversed atrial remodeling
Weight loss
Improved BP control
Improved glycemic control
Reduced inflammation
Improved autonomic tone
What is AF burden
Duration/numbers of longest AF episode
percentage of time
What is AF freedom
Absence of AF period
