Atrial Fibrillation

Question 1

What is A fib ?

Answer 1

• an abnormal heart rhythm characterized by rapid and irregular beating of the atria

Question 2

What happens during A-fib

Answer 2

• signal moves around the atria in a completely disorganized way, that tends to override the sinus node.
• so instead of having one big contraction of the atria, we get mini contractions making it look like the atria is quivering

Question 3

A-fib: ECG

Answer 3

• Irregular
• no P waves
• narrowed QRS as some of the electrical impulses pass through
• HR: 100 - 175 bpm

Question 4

A-fib: causes

Answer 4

• cardiovascular diseases causes: HTN, coronary artery disease, valvular diseases.
  Anything that can create an inflammatory state or physically stretch out the atria and damage the cells in the atria
• non-cardiovascular diseases causes: Obesity, diabetes, excessive alcohol consumption
• Genetic components

All lead to stressing the cells in the atria, leading to tissue heterogeneity -> cells start taking on different electrical properties.

Question 5

What are the different types of A-fib

Answer 5

• Paroxysmal A-fib
• Persistent A-fib
• long-standing persistent A-fib

Question 6

Type of A-fib: Paroxysmal A-fib

Answer 6

• when AF suddenly comes and goes
• last less than a week
• because the tissue is still relatively healthy
• but continuous paroxysmal events can stress the atria cells and lead to persistent A-fib

Question 7

Type of A-fib: Persistent A-fib

Answer 7

• lasts more than a week without self-terminating

- can last weeks to months

Question 8

Type of A-fib: Long standing persistent A-fib

Answer 8

• episodes last beyond 12 months

and Permanent AF, is what’s called when the patient and clinician make the decision not to attempt stopping the rhythm

Question 9

A-fib: Symptoms

Answer 9

• general fatigue: as blood is delivered less effectively to the tissues
• dizziness
• shortness of breath
• weakness
• palpitations, or thumping in their chest

Question 10

A-fib: complication

Answer 10

• stroke
  Because the blood sits in the atria and becomes more stagnant. Stasis -> blood formation.
  Can travel and go to the brain -> causing ischemic stroke

Question 11

A-fib: Diagnosis

Answer 11

• ECG, in case of paroxysmal A-fib, use holter monitor: a portable device placed on the chest that monitors their rhythm over longer periods of time and records potential AF events

Question 12

A-fib: T

Answer 12

• T is different from patient to patients because AF is caused by such a diverse range of tissues
• med to control the HR
• med to reduce likelihood of blood clot formation and prevent stroke
• implantable cardiac pacemaker
• radiofrequency catheter ablation: destroy certain areas of tissue so that electrical signal doesn’t propagate anymore
• ablation of the AV node -> need of an implantable pacemaker to make sure the ventricles contract a high enough rates

Question 13

Routine evaluation

Answer 13

• thyrotoxicosis, valve disease, PE, coronary ischemia, alcohol, pericarditis

Question 14

Treatment of Acute A-fib (48h)

Answer 14

Treat the underlying cause, stroke prophylaxis, treatment of arrhythmia

• if hemodynamically compromised -> external synchronized DC cardio version under general anesthesia
• treat associated illnesses
• control ventricular rate: 1st BB, non-dihydropyridine Ca blocker, 2nd digoxin
• Rhythm control: flacainide, stall, propafenone, disopyramide, quinide
• full anticoagulation with heparin

Question 15

Treatment of chronic

Answer 15

• control rate: medical (BB, CCB, digoxin, amiodarone), Pacemakers (AAI, DDD), atrial defibrillators, catether surgical ablation
• anticoagulants: warfarin INR 2-3 or aspirin 325mg/day