A comparison of the effects of desflurane, sevoflurane and propofol on on QT, QTc and P dispersion on ECG

The Editor, We read with great interest the recent report by Kazancύ et al.[1] on the comparison of the effects of desflurane, sevoflurane and propofol on QT dispersion (QTd), corrected QT dispersion (QTc) and P dispersion (Pd) on electrocardiogram (ECG) in patients undergoing non-cardiac surgery. Although in a metaanalysis it was shown that desflurane and sevoflurane reduce the post-operative mortality and incidence of myocardial infarction following cardiac surgery in terms of post-operative cardiac troponin release, need for inotropic support, time on mechanical ventilation and overall hospital stay, [2] there is no trial investigating the potential arrhythmic effects of these agents in patients undergoing cardiac surgery or in patients with any cardiac disase. According to us, the most interesting part of this study was that the study was performed without pre-medication and that ύt investigated the specific, individual effects of desflurane, sevoflurane and propofol. Further, it was the first study that studied the effects of anesthetic agents on P dispersion.[3] From many metaanalyses, we know that QTd increases in patients with coronary heart disease and hypertrophic cardiyomyopathy, and in heart failure patients, and that p-wave dispersion is influenced by the presence of valvular heart disease, ischemia, autonomic tone, etc. Although in this study, and in the study by Yύldύrύm et al.[4] desflurane was found to cause QTd prolongation, no cardiac dysarhythmia was detected in both studies. Hence, as mentioned before, this was the first study that showed that desflurane caused a significant increase in Pd. In this study, sevoflurane and propofol were found to cause no change in QTd. QTd increase in the desflurane group may be thought to be related to its sympathetic activity. As all the three agents were shown to cause no significant arrhythmias and no changes in QTc, QTcd and Pd, except for desflurane, we wonder about their potential arrhythmic effects in patients undergoing cardiac surgery and in patients with predisposing factors for QTd and Pd. Although such volatile anesthetic agents during non-cardiac surgery are recommended in patients at risk for myocardial infarction by American college of cardiolgoy /American heart association guidelines, can they be used safely in patients with coexisting cardiac disease or in patients undergoing cardiac surgery without causing any arrhytmia?