RESUMO
We intend to study the pattern of atrioventricular conduction blockage in hypothyroidism in elderly population and assessment of any reversal after Lthyroxin therapy. Aims : 1) To detect hypothyroid related AV block in elderly hypothyroid patients. 2) To supplement L-thyroxin for 6 weeksand check whether the AV conduction is restored or not. Settings and design : The proposed study is a hospital based case control study followed by interventional one. Hypothyroid elderly subjects attending OPD over a period of one year were considered for the purposes of observation. Age and gender matched controls were selected simultaneously. Methods and materials : 42 elderly (>60 years) hypothyroid patients were selected as case and 45euthyroid sage and gender matched subjects as control. ECG was done to asses the degree of AV block. Any degree of AV conduction block noted, was supplemented with L-thyroxin for 6 weeks and later resting ECG was done to assess whether the normal AV conduction was restored or not. Statistical analysis : Chi square test done between the case and control group and paired T test done before and after L-thyroxin supplementation. Results : Chi square test revealed that out of 42 cases, a significant proportion of 62% had increased P-R interval (P<.001), whereas 76% out of 45 control had normal P-R interval.After L-thyroxin supplementation in 69% of the cases, normal P-R interval was restored (P< .001, paired T test value 13.484). Conclusion : In hypothyroid patients AV block detected in resting ECG should be a matter of concern, because if the conduction block is reversed to normal sinus rhythm by thyroxin supplementation, unnecessary pacemaker implantation can be avoided.