Twelve-lead high-frequency QRS electrocardiography during anesthesia in healthy subjects.

Analysis of the high-frequency (HF) components of the QRS complex has been shown to be a more sensitive indicator of myocardial ischemia and infarction than conventional ST segment analysis in settings outside of the operating room. In this study, we documented the effect of general anesthesia on HF QRS analysis in healthy patients as the first step in determining the potential of this technique for monitoring anesthetized patients. HF QRS electrocardiograms (ECGs) were obtained from all 12 ECG leads in 30 healthy subjects before and after the induction of anesthesia. When compared with preinduction values, there were significant postinduction changes in multiple variables of the HF QRS in many leads studied that were within previously described normal limits. Additional study is needed to understand the potential of this monitoring technique for enhancing detection of myocardial ischemia in the anesthetized population.