SUBCLINICAL HYPERTHYROIDISM AND OVERT HYPERTHYROIDISM AS A RISK FACTORS FOR ATRIAL FIBRILLATION IN AL- NASIRIYAH CITY

Abstract

ABSTRACTBackground Atrial fibrillation is a well known manifestation of hyperthyroidism , we studied whether subclinical hyperthyroidism in clinically euothyroid persons is a risk factor for atrial fibrillation . Method we studied 267 persons , the subject was classified into 3 groups according to the serum TSH group I: ( 174 ) persons compromised those with normal values of serum TSH ( 0.25 – 5 μU/ml) and T3 , T4 within normal limit , this group considered as control group.group II: ( 61 ) persons those with low serum TSH ( < 0.25 μU/ml) and with elevated serum T3 and T4 i.e overt hyperthyroidism. group III: ( 32 ) persons those with low serum TSH ( < 0.25 μU/ml ) and T3 and T4 within normal limit i. e. sub clinical hyperthyroidism .Result: Atrial fibrillation ( AF ) was presented in 4 only from 174 with a percent of ( 2.3 %) in group I ,but 9 only from 61 persons with a percent of ( 13.8 %) were presented in group II , while 4 only from 32 persons with a percent of ( 12.7 %) in group III .There is significant difference ( P < 0.01 ) between group I when it compared with other groups . Conclusion: Low serum thyrotropin concentration is associated with more than 5 fold higher likely hood for the presence of AF with no significance difference between subclinical and overt hyperthyroidism .