Atrial fibrillation may occur in all of the following conditions, except-
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, with an overall prevalence of 0.5% in the adult population of the UK. The prevalence rises with age, affecting 1% of those aged 60-64 years, increasing to 9% of those aged over 80 years. It is associated with significant morbidity and a twofold increase in moality. This is mainly because of its association with underlying hea disease but also because of its association with systemic embolism and stroke. Pathogenesis AF is a complex arrhythmia characterised by both abnormal automatic firing and the presence of multiple interacting re-entry circuits looping around the atria. Episodes of AF are initiated by rapid bursts of ectopic beats arising from conducting tissue in the pulmonary veins or from diseased atrial tissue. It becomes sustained because of re-entrant conduction within the atria or sometimes because of continuous ectopic firing . Re-entry is more likely to occur in atria that are enlarged or in which conduction is slow, as is the case in many forms of hea disease. During episodes of AF, the atria beat rapidly but in an uncoordinated and ineffective manner. The ventricles are activated irregularly at a rate determined by conduction through the AV node. This produces the characteristic 'irregularly irregular' pulse. The ECG shows normal but irregular QRS complexes; there are no P waves but the baseline may show irregular fibrillation waves. Commonly, AF is classified as paroxysmal (intermittent episodes that self-terminate within 7 days) Ref Harrison 20th edition pg 1534
Mitral stenosis
Hypothyroidism
Dilated cardiomyopathy
Mitral regurgitation
C.V.S