Echocardiographic parameters in patients with positive head up tilt test

Background: syncope, defined as a sudden transient loss of consciousness with complete neurologic recovery. The reduction in cardiac output is a result of decreased stroke volume due to decreased venous return from blood pooling in the lower limbs venous and splanchnic circulation secondary to impaired splanchnic vasoconstriction. The aim of the study was to determine the predictors of positive head-up Tilt Test in patients with vasovagal syncope using echocardiography.Methods: The current study is a cross-sectional study involving 180 patients with acute myocardial infarction undergoing primary percutaneous coronary intervention, admitted to the Coronary Care Unit in Zagazig University Hospitals in the period between January 2019 and January 2020. They were classified into two groups: Group 1 (Low thrombus burden of culprit vessel). Group 2 (High thrombus burden culprit vessel).Results:The demographic data of the studied patients, the mean age was 27.7 years ranged from 18 to 40 years and 54.8% of them were males. Their body surface area ranged from 1.1 up to 2.1 m2 . 64.3% o the studied group showed positive results of head tilt up test and gave the response within time range from 5 min. up to 29 min., the commonest response type was mixed response among 51.9% of HTT positive group. shows that both LAVI and IVC either supine or standing position was significantly lower among HTT positive group than negative group, while no significant difference regarding other ECHO parameters. shows that after multivariate logistic analysis, both LAVI on standing position and IVC supine and standing were significant predictors of positive HTT results. Conclusion: Small LA volume in standing position and IVC diameter in supine and standing position in addition to their percentage of change between supine and standing position are independent predictors of HTT-induced VVS.