Effects of balanced propofol sedation on QT, corrected QT, and P-wave dispersion on upper endoscopy

OBJECTIVE Combined sedation with propofol and benzodiazepines, known as balanced propofol sedation (BPS), was developed to increase patient comfort during endoscopy. However, the effects of BPS on P-wave dispersion (Pwd), QT interval, and corrected QT (QTc) interval after endoscopy have not been investigated. METHODS The study population consisted of 40 patients with BPS and 42 without sedation who were scheduled to undergo upper endoscopy in this cross-sectional prospective study. Patients with hypertension, diabetes mellitus, renal failure, chronic obstructive pulmonary disease, coronary artery disease, or valvular heart disease and those on medications that interfere with cardiac conduction times were excluded. Electrocardiograms (ECGs) was recorded in all patients pre-endoscopy and 10 min post-endoscopy. QT, QT dispersion (QTd), and Pwd were defined from 12-lead ECG. The QTc interval was calculated using Bazett's formula. All analyses were performed using SPSS 15.0. RESULTS Post-endoscopy P max duration and Pwd were prolonged compared with baseline values (86±13 ms vs. 92±10 ms and 29±12 ms vs. 33±12 ms, respectively; p<0.05). Post-endoscopy QTc and QTd were decreased compared with baseline values, but these decreases were not statistically significant (431±25 ms vs. 416±30 ms and 62±28 ms vs. 43±22 ms, respectively; p>0.05). CONCLUSION The present study showed that P-wave duration and Pwd values increased after endoscopy with a combination of midazolam and propofol sedation. Physicians should be made aware of the potential effects of BPS in terms on P-wave duration and Pwd values.