Atrial Fibrillation + Heart Failures Flashcards
What is atrial fibrillation?
Disorganised electrical activity in the atria leads to an irregularly irregular pulse
What effects can atrial fibrillation have on the body?
Irregularly irregular ventricular contractions
Tachycardia
Heart failure
Increased stroke risk
Why can heart failure occur with atrial fibrillation?
Impaired filling of the ventricles in diastole since the atria and ventricles spend less time in diastole
Why are patients at an increased risk of stroke with atrial fibrillation?
Impaired emptying of the atria into the ventricles leading to stasis of blood (time in diastole is less) leads to coagulation of blood which can exit via the carotid arteries
(Often the left atrial appendage)
How are ventricular contractions (QRS) affected by atrial fibrillation?
Irregularly irregular ventricular contraction:
The chaotic rapid irregular atrial electrical actiivty overrides the organisation by the SAN
What is the mnemonic used to remember the most common causes of Atrial fibrillation?
SMITH
What are the most common causes of atrial fibrillation?
Use the mnemonic
SMITH
S - Sepsis
M - Mitral valve issues (stenosis or regurgitation)
I - Ischaemic Heart Disease
T - Thyrotoxicosis
H - Hypertension
What are some lifestyle causes of atrial fibrillation?
Alcohol binging
Caffeine (xanthine oxidase inhibitor)
How may a patient with atrial fibrillation present?
Palpitations
SOB
Dizziness/SYNCOPE
Symptoms of common causes of atrial fibrillation (SMITH)
How can you exclude ventricular ectopics as a differential for atrial fibrillation?
When having ECG monitoring , when exercise occurs (inc heart rate) the ventricular ectopics will disappear
What ECG changes are found on an ECG showing atrial fibrillation?
Absent P waves
Irregularly irregular ventricular rhythm (QRS)
Narrow QRS complex tachycardia
What is paroxysmal Atrial fibrillation?
Episodes of atrial fibrillation that reoccur and spontaneously resolve back to sinus rhythm
How do you investigate a potential paroxysmal atrial fibrillation?
Normal ECG
If normal ECG negative do:
-24hr ambulatory ECG
-Cardiac event recorder (1-2wks)
What is valvular atrial fibrillation?
AF with significant mitral stenosis or mechanical heart valve
What is non-valvular atrial fibrillation?
AF without valve pathology or valve pathology that is not mitral stenosis
What are the 2 categories of mediations for treating atrial fibrillation?
Rate or rhythm control
Anticoagulation
What medications are most patients with atrial fibrillation put on?
Bisoprolol
Apixaban or rivaroxaban.
What is the purpose of giving Bisoprolol or a CCB in managing atrial fibrillation?
Reduce the heart rate to increase the amount of time in diastole so ventricles can more efficiently fill with blood
When are rate control medications not the first line medication for treating atrial fibrillation?
Reversible cause of AF
New onset atrial fibrillation. (Within last 48hrs)
Heart failure due to AF
Symptoms despite effective rate control
What classes of mediations are suitable for rate control when managing an atrial fibrillation?
Beta blocker = first line (bisoprolol or atenolol)
CCB (diltiazem or verapamil)
Digoxin
What patients can CCB like diltiazem or verapamil not be recommended for with atrial fibrillation?
Patients with heart failure
What are the 2 strategies for rhythm control for atrial fibrillation?
Cardio version
Long term rhythm control medications
When can rhythm control be offered to patients with atrial fibrillation?
Reversible cause of AF
New onset atrial fibrillation. (Within last 48hrs)
Heart failure due to AF
Symptoms despite effective rate control
When do you do immediate cardioversion for a patient with atrial fibrillation?
Atrial fibrillation has been present for less than 48hrs
Causing life threatening haemodynamic instability
What are the 2 options for cardioversion?
Pharmacological cardioversion
Electrical cardioversion
What are the pharmacological options for cardioversion?
Flecainide
Amiodarone
What situation would you choose amiodarone over flecainide to pharmacologically cardiovert a patient?
When the patient has structural heart disease
Flecainide not suitable for old patients with structural heart disease
When is delayed cardioversion carried out for atrial fibrillation?
AF present for more than 48hrs and the patient is stable
What medications are given to a patient before delayed cardioversion?
Anti-coagulation like Apixaban and rivaroxaban 4 weeks before
Rate control like bisoprolol
Why are patients anticoagulated 4 weeks before delayed cardioversion when they have AF and are stable?
Clot could’ve formed and returning them back into sinus rhythm could send off the clot
What medications can be given for rhythm control with atrial fibrillation?
Beta blockers
Dronedarone
Amiodarone (HF or LV dysfunction)
What is the management for paroxysmal atrial fibrillation?
Pill in the pocket approach
Flecainide pill taken when symptoms
Anticoagulation
What is the option for a patient with atrial fibrillation if drug control for rate and rhythm is not adequate or tolerable?
Ablation
What are the 2 types of ablation done if medications aren’t suitable for atrial fibrillation control?
Left atrial ablation
AVN ablation and permanent pacemaker
What are the 2 types of anticoagulation that can be offered to patients with atrial fibrillation?
DOACs (apixaban or rivaroxaban)
Warfarin (if DOACs contraindicated)
What must be done if a patient has a fall and they are anticoagulated?
CT head
What are some DOACs that are often used in atrial fibrillation?
How do they work?
Apixaban
Rivaroxaban (Factor Xa inhibitors)
Edoxaban
Dabigatran (direct thrombin inhibitor)
What is the reversal agent for apixaban or rivaroxaban?
Andexanet alfa
What is the reversal agent for dabigatran?
Idarucizumab
What are the advantages of DOACs like apixaban over warfarin?
Doesnt need INR monitoring
No major interactions
Same or better than warfarin
Same or lower bleed risk than warfarin
How does Warfarin work?
Vitamin K epoxide reductase inhibitor
What are the issues with Warfarin?
Needs close INR monitoring since it increases the prothrombin time
INR can fluctuate making patient more likely to have clots or bleed
Many drugs like antibiotics affect its metabolism by CYP450s in the liver (cranberry juice, alcohol)
Leafy green veggies make it not work as well
What is the reversal agent of warfarin?
Active vitamin K and/or Prothrombin complex concentrate
What is the screening tool used to decided whether patients with atrial fibrillation should receive anti-coagulation?
CHA2DS2-VASc
What is CHA2DS2-VASc?
Mnemonic to remember the scoring factors suggesting a patient should start anticoagulation with atrial fibrillation
What does the mnemonic CHA2DS2-VASc stand for?
The risk factors that score a point for needing Anticoagulation in AF
C - Congestive heart failure
H - Hypertension
A2 - Age > 75 (scores 2)
D - Diabetes
S2 - Stroke or previous TIA (scores 2)
V - Vascular disease
A - Age 65 - 74
S - Sex (Female)
What are the results of scores from the CHA2DS2-VASc for Anticoagulation consideration?
0 = no anticoag
1 = consider anticoagulation in men (not women since women automatically score 1) PATIENT and Dr discussion on whether appropriate
2 + = GIVE ANTICOAGULATION
What is the scoring system used to assess a patients bleeding risk before giving anticoagulants?
ORBIT score
HAS-BLED
What is chronic heart failure?
Clinical features of impaired heart function specifically the left ventricle reducing cardiac output, tissue hypoperfusion, increased pulmonary pressures and tissue congestion
What respiratory issue often arises due to chronic heart failure?
Pulmonary oedema
Why does pulmonary oedema occur with heart failure?
Increased volume and pressure of blood in the left ventricle backs up to the atrium then into the pulmonary veins and the lungs
What are the 2 classes of heart failure?
Heart failure with reduced ejeection (HFrEF)
Heart failure with preserved ejection fraction (HFpEF)
How do you work out ejection fraction?
Stroke volume / End Diastolic Voluume
What is considered a reduced ejection fraction?
HFrEF?
Ejection fraction < 40%
Stroke vol/EDV
What is considered a preserved ejection fraction?
Ejection fraction > 50%
What would the broad issue with the heart be if a patient has a reduced ejection fraction. (HFrEF)?
Ejection / emptying problem of the ventricles (systolic dysfunction)
What would the broad issue with the heart be if a patient has a preserved ejection fraction. (HFpEF)?
Filling issue
Diastolic dysfunction.
What typically causes heart failure with a reduced ejection fraction(HFrEF)?
Muscle walls thin and fibrosed
Chamber space enlarged
Abnormal Or uncoordinated contraction
What typically causes heart failure with a preserved ejection fraction(HFpEF)?
Chambers to stiff
Ventricle walls to hypertrophied
What are the overall conditions that cause heart failure?
Ischaemic Heart Disease
Valvular heart disease (AORTIC STENOSIS)
HTN
Arrhythmias (AF)
Cardiomyopathy
What are the symptoms of chronic heart failure?
Breathlessness (worse by exertion)
Cough (pink white frothy sputum)
Orthopnoea
Paroxysmal nocturnal dyspnoea
Peripheral oedema
Fatigue
What is orthopnoea?
Breathlessness when lying flat (how many pillows do you sleep with)
What is paroxysmal nocturnal dyspnoea?
Patients wake at night with severe shortness of breath cough and wheeze
May feel suffocated and may walk around wanting fresh air
What is the pathophysiology of paroxysmal nocturnal dyspnoea?
Lucid settles across large surface area of the lungs while sleep
While asleep respiratory centre in brain less responsive so RR doesn’t increase so patient can become more congested and hypoxic before they wake up feeling unwell
What can you find on examination of a patient with chronic heart failure?
Tachycardia
Tachypnoea
HTN
Murmurs if caused by valvular disease
3rd heart sounds
Bilateral basal crackles (oedema)
Raised JVP
Peripheral oedema
What investigations would you do for a patient who you think might have heart failure?
NT-proBNP
ECG
Echocardiogram
Bloods (Anaemia, renal function, thyroid, liver,lipids , diabetes)
CXR
Lung function tests
What is the classification system for heart failure?
New York Heart Association Classifaction (NYHA)
What are the classes of heart failure according to the NYHA classification?
Class I: No limitation on activity
Class II: Comfortable at rest but symptomatic with ordinary activities
Class III: Comfortable at rest but symptomatic with any activity
Class IV: Symptomatic at rest
What is the purpose of measuring NT-proBNP if suspecting heart failure?
Indicates how soon an Echo should be done in
What is the management for heart failure with reduced ejection fraction?
Furosemide
ACEi (Ramipril) can give ARB if not tolerated
Beta-blockers (Bisoprolol)
Give Spironolactone if the above given and still have issues
Cardiac rehab
When should an ACEi be avoided with a patient with heart failure?
When it’s caused by valvular heart disease
What medications can be given to a patient with Heart failure with preserved ejection fraction?
Furosemide
Then manage co-morbidities
Cardiac rehab
What additional medications can be given in heart failure with reduced ejection fraction (HFrEF)?
SGLT2 inhibitor (dapagliflozin)
Entresto (Sacubitril valsartan)
Ivabradine
Digoxin
Hydralazine with nitrate
What needs to be regularly monitored in patients being treated for HFrEF?
U+Es
Why do U+Es need regularly monitoring when managing HFrEF?
Loop diuretics , ACEi and aldosterone antagonists cause electrolyte disturbances
ACEi and Aldosterone antagonists can both cause HYPERKALAEMIA
What are some procedural or surgical interventions to manage chronic heart failure?
Surgery for valvular causes
Implantable cardio defibrillators if theres a shockable arrhythmia
Cardiac re synchronisation therapy
Transplant if serious
What are the criteria for being on apixaban as an anticoagulant with AF?
eGFR > 15
Age > 75
Weight < 60kg
What anticoagulant must a patient be on if they have atrial fibrillation with very poor renal function eGFR < 15 ?
Warfarin
What electrolyte abnormality can cause atrial fibrillation?
Hypokalaemia
What can you cardiovert a patient in AF without Anticoagulation?
When must you use Anticoagulation and for how long?
AF < 48hrs can cardiovert without anticooagulation
AF > 48hrs need 4 weeks of Anticoagulation before cardio version
What doses of flecainide can be used as an acute rhythm control for AF?
How is it given?
IV infusion or 300mg Oral
What dose of amiodarone can be given to acutely rhythm control AF?
How is it given?
300mg IV bolus
What patients cant you give flecainide to cardiovert for AF?
Who can you give it to?
Cant = structural heart disease (typically older patients)
Can = young people with no structural abnormalities
What patients can you give amiodarone to cardiovert for AF?
Works well with structurally damaged hearts
Why shouldn’t you give a beta blocker (bisoprolol) at the same time as a calcium channel blocker like verapamil and Diltiazem?
Would cause complete heart block
How would you investigate a pateitn who presents with SOB, palpitations, light headends and fatigue?
FBC
U+Es (?hypokalaemia)
Obs
TFTs
D-dimers
Chest x-ray
ECG (cardiomegaly?)
Auscultation for valve issues
What score must always be calculated for a patient with AF?
CHA2DS2-VASc
What are the consequences of an untreated atrial fibrillation?
HFpEF
Left atrial remodelling / enlargement
Tachycardiomyopathy
Strokes/acute limb ischamia
Longer stay in AF more likely to return to AF from sinus
What is tachycardiomyopathy?
When dilation/enlargement of the ventricles occurs leading to a rapid ventricular rate due to the fast heart rate
When the AF is treated this will resolve
When can you have a slow. AF?
AF + Complete heart block
What condition with AF requires electrical cardio version and then ablation?
AF with pre-excitation
Emergency cardio version needed to return into sinus rhythm then ablation of the accessory pathway needed
How should a patient be managed if it’s there first time having AF and no other underlying issues?
Give rate control (bisoprolol) send home and get them to come in the next day to see if they have spontaneously returned back into sinus rhythm. If they haven’t then you can electrically cardiovert them without Anticoagulation since its been less than 48hrs
