iarjmsIARJMSIARJMS2708-3594https://doi.org/10.47310/iarjms.2021.v02i02.021Prevalence of Tachycardia among infant with Congenital Heart DiseaseAbhinavGautamDeepakKumarSharmaBackground: Tachycardia figure prominently among the complications encountered in the varied and diverse population of patients with congenital heart disease. The aim of the study is to find the prevalence and association between tachycardia and congenital heart disease (CHD) in newborns/infants living at High Altitude. Material and Methods:  This was a Cross-sectional observational study included children age between 0 to 1 year with suspected heart disease came to outdoor and indoor services of Department of Pediatrics IGMC, Shimla from July 2018 to June 2019. Results: In our study there were 102 participants in total. Out of them 57 participants were ≤1 month of age i.e. 57(55.90 % of total, 29(28.4%) between 2-6 months,16(15.7%) between 7-12 months. There were 55 males and 47 females. In the present study, tachycardia was present in 55(53.9%) out of 102 study participants and out of these 55 patients, 48 were diagnosed with underlying CHD. Odds ratio was 2.7 with CI (1.2-5.94), with p value of 0.019, which is significant.  The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of tachycardia in diagnosing CHD is 83.54 % ,56.54%, 86.84 % and 50.0% respectively. Conclusion: There were high sensitivity and positive predictive value (PPV) of tachycardia in diagnosing CHD.  So, Tachycardia can be considered as a significant parameter in screening of CHD in children age less than one year living at high altitude.