According to recent researches about the importance of prognostic
   value of QT dispersion (QTD) in patients with acute myocardial infarction ,
   the present study was performed to assess the relationship between QT
   dispersion increment and incidence of ventricular fibrillation in patients
   with acute myocardial infarction.

          QT dispersion was calculated by caliper in the first 24 hour’s ECG after
   acute myocardial infarction in 30 cases of AMI that complicated by
   ventricular fibrillation and was compared with 200 cases without
   ventricular fibrillation . Also some information about primary or secondary VF
   ,EF (according to echocardiography) were recorded in check list. The study
   was a descriptive , cross - sectional study.

          Direct relationship between QT increment and mechanical dysfunction
   of left ventricle (EF < 40%) was showed . In patients with primary VF the
   mean of QTD was 20 msec more than the patients with secondary VF. In
   patients with  acute myocardial infarction (AMI) that complicated with VF
   the QTD was greater than the patients without VF.

          According to above results we can use QTD as a cheap ,easy and
   available method for diagnosis of increased incidence of VF in patients with
   AMI.