The Management and Outcome of Documented Intraoperative Heart Rate–Related Electrocardiographic Changes Ion A. Hobai, MD, PhD,* Cosmin Gauran, MD,* Hovig V. Chitilian, MD,* Jesse M. Ehrenfeld, MD,* John Levinson, MD,† and Warren S. Sandberg, MD, PhD* Objectives: The authors analyzed surgical cases in which electrocardiographic (ECG) signs of cardiac ischemia were noted to be precipitated by increases in heart rate (ie, heart rate–related ECG changes [REC]). The authors aimed to find REC incidence, specificity for coronary artery disease (CAD), and the outcome associated with different management strategies. Design: A retrospective review. Setting: A university hospital, tertiary care. Participants: Patients undergoing surgery under anesthesia. Interventions: A chart review. Measurements: The authors searched 158,252 anesthesia electronic records for comments noting REC (ie, ST-segment or T-wave changes). After excluding cases with potentially confounding conditions (eg, hypotension, hyperkalemia, and so on), 26 cases were analyzed. Results: REC commonly was precipitated by anesthesia- related events (ie, intubation, extubation, and treatment of bradycardia). In 24 cases, REC was managed by prompt heart rate reduction using -blocker agents, opioids, and/or cardioversion in the addition to the removal of stimulus. Only 1 case had a copy of the ECG printed. Two cases were aborted, 1 was shortened and 23 proceeded without change. Postoperative troponin T levels were checked, and cardiol- ogy consultation was obtained in selected cases and led to further cardiac evaluation in 6 cases. Postoperative myocar- dial infarction developed in only 1 patient in whom the ECG changes were allowed to persist throughout the case. Conclusions: This incidence of reported REC was much lower than the previously reported incidence of ischemia- related ECG changes, suggesting that the largest proportion of events go unnoticed. In many patients, subsequent car- diology workup did not confirm the existence of clinically significant CAD. © 2011 Elsevier Inc. All rights reserved. KEY WORDS: intraoperative complications, cardiac isch- emia, myocardial infarction, mortality A NNUALLY, AN ESTIMATED 100 million adults un- dergo noncardiac surgery worldwide, and between 1% and 5% of them develop major perioperative cardiac events, such as cardiac death, nonfatal myocardial infarction (MI), and cardiac arrest. 1 The occurrence of a perioperative MI (PMI) confers an in-hospital mortality of 15% to 25% 1 and an 18-fold increase in the combined risk of cardiovascular death and a second MI in the following 6 months. 2 Therefore, a sustained scientific effort is committed to identifying clinical predictors for PMI as well as interventions that may decrease the risk. 3 Among clinical predictors of PMI, the development of intra- operative cardiac ischemia is one of the most concerning. That is because, retrospectively, most cases of PMI (84%, in a study in high-risk vascular patients 4 ) are preceded by long periods (hours 4 ) of electrocardiographic (ECG) signs of cardiac isch- emia. 4-7 However, when studied prospectively, the predictive value of perioperative ECG changes for PMI is relatively poor. In patients with known coronary artery disease (CAD), periop- erative ECG changes indicative of ischemia may occur fre- quently (in as high as 41% of patients in an 1990 study 5 ) but only herald subsequent PMI in a minority of patients (7% in this study 5 ; similar conclusions were reached by others 6,7 ). In patients with moderate CAD risk, 8 ischemia-related ST-seg- ment depressions occur much less frequently (3.6%) and have no association with the development of PMI (or even the presence of clinically significant CAD 8 ). In 1 particular group of low-risk patients, ST-segment depressions are observed fre- quently during cesarean section operations and are not associ- ated with CAD. 9 Therefore, when the signs of cardiac ischemia occur intra- operatively, their management is often debatable (or at least is not supported by scientific evidence). When ECG changes occur in the setting of increased cardiac stress (such as an increase in heart rate [HR], ie, rate-related ECG changes [REC]), the accepted practice is to immediately attempt to decrease the HR and confirm REC resolution. However, it is not known whether this is necessary in all patients (such as in a young, otherwise healthy patient at low risk for CAD) and whether these measures are associated with the prevention of PMI. In some patients (judged to be at high risk for PMI), management may include advancing the level of monitoring (such as implementation of invasive blood pressure moni- toring) or airway control (endotracheal intubation), recom- mending a postoperative cardiology consult and even the cancellation of the surgical procedure. However, these in- terventions are not without risk (or cost), and their potential benefit is unknown. To address this issue, the authors undertook a review of a large database of anesthesia records. All cases in which REC were noted and specifically managed by the anesthesia provider were identified and studied. The authors aimed to find out the incidence, inciting factors and intraoperative management of REC, which cases were cancelled or followed by further in- vestigations, and whether these management strategies led to a decrease in the incidence of PMI. METHODS This retrospective study was approved by the Institutional Review Board of the Massachusetts General Hospital, Boston, MA. The au- thors’ institution uses an Anesthesia Information Management System From the Departments of *Anesthesia, Critical Care and Pain Med- icine and †Internal Medicine, Massachusetts General Hospital, Bos- ton, MA. J.M.E and W.S.S are currently affiliated with the Department of Anesthesiology, Vanderbilt University, Nashville, TN. Address reprint requests to Ion A. Hobai, MD, PhD, Department of Anesthesia and Critical Care, Massachusetts General Hospital, GRB 444, 55 Fruit Street, Boston, MA 02114. E-mail: IHobai@Partners.org © 2011 Elsevier Inc. All rights reserved. 1053-0770/2505-0008$36.00/0 doi:10.1053/j.jvca.2011.03.174 791 Journal of Cardiothoracic and Vascular Anesthesia, Vol 25, No 5 (October), 2011: pp 791-798