QT dispersion and corrected QT interval in septic patients in correlation with mortality

Abstract

Background
Sepsis is one of the leading post-surgical or post-traumatic complications in today’s hospitals. This pervasive condition is the major cause of morbidity and mortality in intensive care units worldwide, as well as the leading cause of death in non-coronary patients.


Aim
To study QT dispersion (QTD) and corrected QT interval (QTc) in septic patients in relation to mortality.


Subject and methods
A prospective observational cohort study including 40 adult patients admitted with diagnosis of sepsis at Critical Care Department at Kasr Al-Ainy Hospital and at ICU unit at Ahmed Maher Teaching Hospital. They were monitored with 12-lead ECG for 7 consecutive days for QTc and QTD measurement. QT intervals were measured in milliseconds (ms), and positive QTD was defined as > 50 ms. Twenty healthy participants were included as controls to measure normal QTc and QTD.


Results

It was found that 27.5% of the studied population developed arrhythmias and 60% died. QTD developed in 37.5% of patients during hospitalization and was significantly associated with mortality (
p
-value < 0.001) and need for mechanical ventilation (MV) (
p
-value = 0.002). QTD showed a non-significant trend with QTc (
p
-value = 0.07). Both QTD and QTc were significantly higher in septic patients compared to controls (
p
-values = 0.002 and
P
-value < 0.001, respectively). Neither QTD nor QTc correlated significantly with length of hospital stay, serum electrolytes, arrhythmias, or APACHE II score.



Conclusion
In this small prospective cohort, QTD (> 50 ms) developing during hospitalization was strongly associated with mortality and need for mechanical ventilation in septic patients. These findings suggest QTD may have prognostic value in sepsis; however, the small sample size and single-center design limit generalizability. Larger, multicenter prospective studies with automated QT measurement protocols are needed to validate QTD as a clinical prognostic tool in sepsis.