OBSERVATIONS ON CARDIAC ABNORMALITIES IN PATIENTS WITH DEXTROCARDIA AND SITUS AMBIGUUS: A RETROSPECTIVE STUDY

Studies on dextrocardia have been limited by low numbers. Hence, finding the most common diagnosis in patients with dextrocardia and situs ambiguus is challenging among patients seeking medical attention in a tertiary care center. Aims and objectives: To identify the most common diagnostic pattern in dextrocardia (DC) patients with situs ambiguous (SA). Methods: It is a retrospective study with records dating backto the last 21yrs from a major tertiary care center in South India. In this study, researchers will include all the patients diagnosed with dextrocardia (defined as the right-sided baso-apical axis of the heart). The segmental analysis will be done as described previously. Results: There was a total of n=378 patients with dextrocardia, of which 71 had situs ambiguus with dextrocardia. The mean age was 2.3yrs, 36.6% were females 32 patients had right atrial isomerism (RAI), 18 patients had left atrial isomerism (LAI), and 21 patients had unidentified atrial isomerism (UAI). In the RAI group Double outlet right ventricle (DORV) was present in n=13 (40.6%), Single ventricle (SV) was present in n = 14 (43.8%). In the LAI group, DORV was present in n=5 (27.8%), SV was present in n = 4 (22.2%), and atrioventricular cushion defect (with normally related great arteries) was present in n=4 (22.2%). More patients with LAI had normally related great arteriesthan RAI (50% vs. 15.6%, p<0.05). Conclusion: RAI is the most common type of atrial isomerism in situs ambiguus and dextrocardia patients. The most common diagnoses in situs ambiguus and dextrocardia patients are double outlet right ventricle and single ventricle with pulmonary/sub-pulmonary obstruction. LAI had relatively simpler lesions as compared to RAI. Around one-third of the patients, atrial isomerism could not be identified.