AFib management

Why do we need to do do stroke prevention in Afib patients?

Afib patients have irregular heart beats
This causes turbulent flow
This may cause blood to be stuck in the atrial appendage there is a collection of clotting factors in this appendage
The clot may embolise

What is the treatment approach to Afib?

A- Anticoagualtion (stroke prevention)
B- better symptom control (rate and rhythm control)
C- CV risk (lifestyle intervention)

What is the target heart rate for AFib patient? (no other disease)

80bpm

What is rhythm control all about?

it is to convert to sinus rhythm
Can use direct cardiac conversions, ablations
Can also use drugs, but has more side effects

What are the agents used in rate control?

Beta blocker (any kind, but depends on the patient)
Non-DHP CCB (verapamil, diltiazem)
Digoxin
Amiodarone

How does the rate controlling agent work in general?

They slow AV node conduction.
They block AV node.

It needs to target the AV node, because the abnormal stimuli are bombarding the AV node not the SA node.

Can we use ivabradine in Afib?

No.
There is no point because it acts on the SA node. Not the Av node.

What are the first-line rate control agents?

Beta blockers and non-DHP CCB

What is the first line for HF patients with Afib?

Beta-blockers

chronic HF patients cannot use Non-DHP CCB due to the negative inotropic effect
Acute HF cannot use BB

second-line (if still >110 or still quite high)
Add digoxin, or amiodarone(3rd)

Third line
Ablation

What is the first line for COPD/ Asthmatic patients with Afib?

Non-DHP CCB or Beta-1 Blockers

Cannot use beta-2 blockers or mixed because of the bronchoconstriction

second-line (if still >110 or still quite high)
Add digoxin, or amiodarone (3rd)


Third line
Ablation

What is the heart rate target for someone HF+Afib?

What are some Beta 1 selective BB?

atenolol, betaxolol, bisoprolol, esmolol, acebutolol, metoprolol, and nebivolol.

When do you start on rhythm control?

You start on rhythm control when the patient is still symptomatic despite the rate being well controlled

What's relationship between HF and AFib?

HF begets Afib. Afib begets HF.
They are very closely pathologically related.
HF causing atrial distention, LA enlargement --> AFib
AFib with poor compromised filling, decreased cardiac output --> HF

What is the use of Class I anti-arythmic drug? which pump? Drug?

Rhythm
sodium potassium pumps

What is the use of Class II anti-arythmic drug? which pump? Drug?

Rate
Calcium pumps
Beta blockers

What is the use of Class III anti-arythmic drug? which pump? Drug?

Rhythm
Potassium pump
Amiodarone
Sotalol
Dofitilide
Dronadarone

What is the use of Class IV anti-arythmic drug? which pump? Drug?

Rate
calcium channel blockers
Non-DHP CCB
Verapamil Diltiazem

What are the rhythm drugs used in only Afib patients?

Class IC and III
Amiodarone
Dronedarone
sotalol

What are the rhythm drugs used in Afib + HFpEF, CAD patients?

Class III only
amiodarone
sotalol
Dronedarone

What are the rhythm drugs used in Afib +HFrEF patients?

only amiodarone!

Which classes of drugs are used in rate control?

Class II (beta blockers)
Class IV (Non-DHP CCB)
Digoxin

What can BB used to prevent?

BB used to prevent ventricular arrhythmia in the post myocardial infarction period

How does digoxin work in Afib?

Direct
Directly slows down the conduction between SA and AV, increasing refraction period and decreasing the conduction velocity, decreasing rate

Indirectly
Enhances vagal tone
Increases parasympathetic activity which slows the AV node conduction, this decreases rate.

How does digoxin work in heart failure?

inhibits the Na/K ATPase, increases Na conc, increases Ca influx, increases contractility!

What is the patient is fluid overload?

Use digoxin or amiodarone first!
Cannot use BB.

What do you need to monitor if you are giving Amiodarone?

Baseline then 6m
Thyroid function test (TFT)
Liver function test (LFT)
Chest-X ray (base-line then every 12m)
ECG (baseline then 3-6m)
Physical exam
Eye test

what are some DDI of amiodarone?

Warfarin
Digoxin
Statins (only rosuvastatin can use)

What is the half life of amiodarone?

It has a very long ass half life 1-3 months

What do you need to watch out when giving sotalol?

Renal funciton
QTc prolongation
Pulse rate and blood pressure

What are the Class IC drugs?

Flecainide
Propafenone

What is the solatol racemic?

L-isomer: Class II and Class II effects
D-isomer: class III effects

What are some adverse side effects of amiodarone?

Pulmonary fibrosis (Chest x-ray, CT)
Hypothyroidism/Hyperthyroidism (TFT)
Optic neuropathy (eye check if vision problem baseline)
Hepatotoxicity (LFT every 6m)
Bradycardia/heart block (ECG every 3-6m)
Tremor, ataxia, photosensitivity.