Background: There are variety of established causes of bradycardia (Heart rate <60 bpm), including cardiac & non cardiac diseases, medications & age related degeneration. In few cases we found bradycardia without obvious causes. The patient's, specially in young individuals (age<40 yrs) who have allergic symptoms with bradycardia but without any obvious cause, hyperimmunoglobulin E can be a possible cause. ThisMethods: prospective, cross sectional study included 64 patients aged under 40 years whole have allergic symptoms & ECG showed bradycardia, and in whom no obvious cause of bradycardia was found. In all these cases we have checked S. Immunoglobulin level E & other necessary investigations. Results: Total 64 patients was enrolled with one year of period, among them 42(65.6%) was male & 22(34.4%) was female. Majority of the pt, n- 40(62.5%) was in age group 11-20 years. Total 58 patients S. Immunoglobulin level was found raised, other 6 patients was found within normal range, which is statistically signicant (p<0.05). Follow up ECG & S. Immunoglobulin E was done after 4-6 weeks of symptomatic treatment & found heart rate become normalized with normalized/decreased level of S. Immunoglobulin E. No patients developed any complications during the study period. Raised S. Immunoglobulin E can be a possible cause of bradycardia in young individuals, especially whole haveConclusion: allergic symptoms with no obvious cause of bradycardia.