Manouchehr Hekmat - Department of Cardiovascular Surgery, Shahid Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Hamid Ghaderi - Department of Cardiovascular Surgery, Shahid Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Mahnoosh Foroughi - Clinical Research and Development Center at Shahid Modarres Hospital, Department of Cardiac Surgery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Sima Rafiiyian - Department of Pediatric Cardiology and Pediatric Cardiac Surgery, Shahid Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Zahra AnsariAval - Clinical Research and Development Center at Shahid Modarres Hospital, Department of Cardiac Surgery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Seyedeh Adeleh Mirjafari - Department of Pediatrics, Ali-Asghar Children`s Hospital, Iran University of Medical Sciences, Tehran, Iran

Background: Tetralogy of Fallot (TF) in some Iranian patients is different in that the mitral z-value is significantly lower than normal. The present study was conducted to investigate the effect of the mitral Z-value on post-surgery mortality.Materials and Methods: The present retrospective analytical study was conducted on surgery candidate patients diagnosed with TF who had attended Shahid Modarres Hospital in Tehran between late March ۲۰۱۲ and late March ۲۰۱۹. Once the type of treatment and the need for surgery were decided and the mitral size and Z-value were determined, the patients underwent surgery, and then divided into two groups based on the outcome (death or discharge).Results: A total of ۱۶۰ patients entered the study over seven years, of whom, ۱۱۰ were discharged (group ۱) and ۵۰ died (group ۲). There were no significant differences between the two groups in terms of gender. The patients' mean age was ۸.۹۶±۸.۰۹ years in the group ۱ and ۳.۱۶±۲.۷ years in the group ۲ (P<۰.۰۰۰). Mean mitral Z-value was -۲.۲۶±۲.۱۱ in the group ۱ (ranging from -۷.۱ to +۱.۳) and -۳.۴۸±۱.۷۱ in the group ۲ (ranging from -۶ to -۱.۱), and Independent Sample Test showed no significant difference between the two groups (P=۰.۲۷۱).Conclusion: The mitral Z-value was significantly lower than normal in participating patients with TF, which could indicate hypo-plasticity of the left ventricle in Iranian patients with TF. No significant difference was found between the two groups in terms of surgical complications. In other words, the mitral Z-value had no effect on mortality of patients with TF.

Congenital heart disease, Mitral valve, Tetralogy of Fallot, Mortality, Z-value, Z-score