DR Medhat MRCP

Atrial fibrillation (AF)
Def :
- one of the supraventricular tachyarrhythmia ch. By irregular irregularity of the
heart beats caused by overwhelming of the normal SAN impulses by disorganized
electrical impulses from other ectopic foci usually originating in the roots of the
pulmonary veins, leading to irregular conduction of impulses to the ventricles
which generate the heartbeats.
Causes :
1. Idiopathic.
2. HTN.
3. IHD. Cardiac muscle disease.
4. CHF, HOCM
5. Pericardial disease.
6. Valvular heart disease (most commonly M.S).
7. Thyroid dysfunction( mainly hyperthyroidism).
8. Electrolytes disturbance.
9. Lung disease (eg PE , pneumonia)
10. +ve family history of AF.
11.Excessive alcohol intake , CO poisonin
Pathophysiology :
- Any factor which can cause atrial dilatation(eg causes of AF) later on
patches of atrial fibrosis extending to SAN , AVN & pulmonary veins ectopic
foci sending disorganized impulses overwhelming the normal SAN rhythm or
re-entrant electrical spiral irregular pulse .
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