Atrial Fibrillation with rapid ventricular rate

Definition:
Atrial fibrillation ( AF ) is defined as abnormal irregularly irregular heart rhythm due to rapid, chaotic, asynchronous and incordinated atrial contraction.

Note: always remember 2 point as given below for AF definition,
1, Abnormal irregularly irregular heart rhythm.
2, Rapid, chaotic, asynchronous and incordinated atrial contraction.

In AF, heart rate maybe over 140 beats per minutes.

Types of Atrial fibrillation:
There are three types of atrial fibrillation:

1, Paroxysmal atrial fibrillation

Rapid heart rate begins suddenly and rapidly and stops spontaneously.

Do not necessaryly requre treatment if symptos subsides itself.

If symptoms are persist or troublesome then can use B-blocker and Antiarrhythimic drugs Class IC e.g. Propafenone, Flecainide ( Potent Na+ Channel blockers )

B-blocker is appropriate if structural heart disease, Hypertension and exertion or stress AF.

Amiodarone is second line drug

Digoxin is not effective in case of paroxysmal AF.

Sometimes radiofrequency ablation may also needed if some forms of paroxysmal AF is not relieved by medications.

2, Persistent Atrial fibrillation

Rate control and cardioversion are both effective.

Electrical cardioversion can restore sinus rhythm in case of early AF that is less than 3 months, young patients and no any underlying structural heart disease.

Frequency of relapse is high i.e. approx. 50% within 1 months and 85% within 1 year.

If AF is lessa than 48 hours, immediate DC cardioversion is suitable after the IV heparin administration.

Intravenous Flecainide infusion is safe alternative to Electrical cardioversion if there is no underlying heart disease.

Anticoagulation should be continued for 6 months or must at least 1 months after cardioversion.

If relapse again cardioversion is appropriate.

Antiarrhythmic drugs B-blockers and Amiodarone can reduce risk of recurrence.

3, Permanent Atrial fibrillation

Rate control is mostly effective treatment.

Drugs used for rate controls are Digoxin, B-blockers, Rate limiting Calcioum antagonists e.g. Verapamil or diltiazem.

Controlling rapid heart rate i.e Fast ventricular rate during exercise can be controlled effectively by B-blocker and rate limiting calcium antagonist rather than Digoxin.

Additional benifits in patients with Hypertension and structural heart disease if treated with B-blocker and rate limiting CCB.

If permanent AF is not controlled by any measure can be treated by inducing complete heart block with transvenous catheter radiofrequency ablation and permanent pacemaker must be implanted at the same time.

Causes of AF:
-Exact causes of atrial fibrillation is unknown.

Mnemonics for atrial fibrillation:
ATRIAL'S CARDIAC

A = Acute coronary syndrome ( Atherosclerosis or Ischemic heart disease or MI )***
Amphetamine
T = Thyrotoxicosis
R = Rheumatic heart disease ( Heart Valve disease)***
I = Idiopathic / Increase BP (HTN)***
A= Alcoholism (Holiday heart)*** / Adrenal disease ( Pheochromocytoma )
L = Lone AF***
Lung disease ( Acute Pulmonary embolism**, Pneumonia, Emphysema, COPD, Asthma)
Lung Cancer
S = Sepsis / Shock / Sick sinus syndrome
Smoking
Sleep apnea

C = Congeintal heart disease*** / Congestive heart failure*** /Cardiomyopathy
A = Atrial myxoma
R = Recent heart surgery or Previous heart surgery
D = Diabetes Mellitus
I = Infections ( sepsis, chest infections )
A = Atrial flutter
C = Carbonmonoxice poisoning / Cocaine / Caffeine

*** = Most Common Causes
Other rare causes:
Mesothelioma Cancer
Injury e,g auto mobile accident, road traffic accident, car accident, bike accident.