title: Myocardial Performance Index in Neurocardiogenic Syncope Patients.
abstract: BACKGROUND
  Many syncopes resulting from neural reflexes in various conditions are called neurocardiogenic syncope (NCS). We aimed to investigate the presence of left ventricular (LV) myocardial performance index (MPI) in patients with NCS, which was diagnosed with head-up tilt table test (HUTT), and the accurateness of the test in order to use it as a method in patients with NCS. Assuming the MPI as a potential cause of syncope, we assessed the Tei index with non-invasive tissue Doppler echocardiography method.
  
  
  METHODS
  Consecutive outpatients with a history of recurrent unexplained syncope underwent HUTT. Twenty-nine HUTT (+) patients (24 female and five male, mean age: 30 ± 15 years) as the study group and HUTT (-) 23 healthy patients (six female and 17 male, mean age: 34 ± 16 years) as the control group were included into the study. Conventional and tissue Doppler echocardiography was performed to both groups. The MPI was determined by using PW Doppler. Measurements of Doppler time intervals, according to Tei index ((isovolumic contraction time + isovolumic relaxation time)/ejection time) is calculated as (a - b/b), where "a" is the interval between cessation and onset of the mitral inflow, and "b" is the ejection time (ET) at the LV outflow.
  
  
  RESULTS
  When comparing the groups in terms of MPI and ET, there was significant difference between groups. Patients with NCS had significantly longer ET and lower MPI value than control group (284 ± 24 ms vs. 260 ± 24 ms, P < 0.001, respectively and 0.44 ± 0.7 vs. 0.52 ± 0.8, P < 0.001, respectively). There was no significant difference in ejection fraction between groups.
  
  
  CONCLUSIONS
  In the present study, LV MPI value decreases in patients with NCS.
authors.affiliation: Cardiology Department, Gaziantep University, Gaziantep, Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Yilmaz Coskun
authors.affiliation: Cardiology Department, Gaziantep University, Gaziantep, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Sucu
authors.affiliation: Cardiology Department, Elazig Research and Training Hospital, Elazig, Turkey.
authors.forename: Okkes
authors.initials: O
authors.lastname: Uku
authors.affiliation: Cardiology Department, Gaziantep University, Gaziantep, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Yuce
authors.affiliation: Cardiology Department, Gaziantep University, Gaziantep, Turkey.
authors.forename: Orhan
authors.initials: O
authors.lastname: Ozer
authors.affiliation: Cardiology Department, Gaziantep University, Gaziantep, Turkey.
authors.forename: Suleyman
authors.initials: S
authors.lastname: Ercan
authors.affiliation: Cardiology Department, Gaziantep University, Gaziantep, Turkey.
authors.forename: Vedat
authors.initials: V
authors.lastname: Davutoglu
keywords: Echocardiography; Myocardial performance index; Neurocardiogenic syncope