QTc and P wave dispersion in patients with Cushing's syndrome
Nihal Akar Bayram1, Reyhan Ersoy2, Dilek Tuzun2, Serap Soytac Inancli2, Engin Bozkurt1 & Bekir Cakir2
Introduction: The clinical implications of QTc and P wave dispersion in patients with Cushings syndrome have not been studied previously. In this study, we aimed to compare QTc dispersion and P wave dispersion in patients with Cushings syndrome and healthy subjects.
Material and method: Sixteen patients with Cushings syndrome diagnosed on clinical, laboratory and imaging findings and 16 age and sex matched control subjects were included. All subjects underwent a routine standart 12- lead suface electrocardiograpy recorded at a paper speed of 25 mm/s and gain of 100 mm/mV. Maximum, minimum and mean QT intervals were calculated. Measured maximum and minimum QT intervals were corrected by Bazetts formula (QTc=QT/√RR), and were defined as corrected QT interval (QTc). The difference between the maximum and minimum QTc interval was defined as QTc dispersion and the difference between maximum P wave duration (Pmax) and minimum P wave duration (Pmin) was calculated as P wave dispersion (PWD).
Results: Maximum QTc interval (429.9±24.8 vs 408.4±24.7; P=0.02), QTc interval (389.0±22.0 vs 375.5±11.6; P=0.04) and QTc dispersion (84.9±17.6 vs 70.9±13.2; P=0.02) were significantly longer in patients with Cushings syndrome compared to healthy subjects. There was no significant difference in Pmax, Pmin and P wave dispersion between groups (P>0.05).
Conclusion: We showed that QTc interval and QTc dispersion were increased in patients with Cushings syndrome compared to healthy subjects; however P wave dispersion did not change. Accordingly, significant electrical heart function disturbances which might be life-threatening may occur in patients with Cushings syndrome indicating need for early monitorization by a cardiologist in these patients.