Is there still a role for preoperative 12-lead electrocardiography?

Background  

Twelve-lead electrocardiography is a standard preoperative investigation for patients undergoing major surgery. There is uncertainty and debate over the usefulness of this test for stratifying postoperative cardiac risk. The aim of this study was to investigate the correlation between an abnormal electrocardiogram (ECG) and the postoperative cardiac event rate.     

Perioperative Cardiac Risk Stratification and Modification in Abdominal Aortic Aneurysm Repair

Cardiovascular complications are important causes of morbidity and mortality following vascular surgery. Adequate preoperative risk assessment and perioperative management may modify postoperative mortality and morbidity and improve long-term prognosis. The objective of this review is to examine the present day knowledge regarding the preoperative evaluation and perioperative management of patients undergoing noncardiac surgery, focusing specifically on abdominal aortic aneurysm (AAA) repair.

Clinical markers combined with ECG and surgical risk assessment can effectively divide patients in a truly low-risk, intermediate and high-risk population. Low-risk patients can probably be operated on without additional cardiac testing. Notably, due to the surgical risk, AAA patients are never low-risk patients. Intermediate-risk and high-risk patients are referred for cardiac testing to exclude extensive stress induced myocardial ischemia, as beta-blockers provide insufficient myocardial protection in this case and preoperative coronary revascularization might be considered. Whether patients at intermediate risk without ischemic heart disease should be treated with statins and/or beta-blockers is still controversial. In high-risk patients, it is strongly advised to administer beta-blockers with heart rate determined dose adjustment, while the effects of preoperative revascularization remain subject to debate.     

Perioperative cardiac risk stratification and modification in abdominal aortic aneurysm repair

Cardiovascular complications are important causes of morbidity and mortality following vascular surgery. Adequate preoperative risk assessment and perioperative management may modify postoperative mortality and morbidity and improve long-term prognosis. The objective of this review is to examine the present day knowledge regarding the preoperative evaluation and perioperative management of patients undergoing noncardiac surgery, focusing specifically on abdominal aortic aneurysm (AAA) repair. Clinical markers combined with ECG and surgical risk assessment can effectively divide patients in a truly low-risk, intermediate and high-risk population. Low-risk patients can probably be operated on without additional cardiac testing. Notably, due to the surgical risk, AAA patients are never low-risk patients. Intermediate-risk and high-risk patients are referred for cardiac testing to exclude extensive stress induced myocardial ischemia, as beta-blockers provide insufficient myocardial protection in this case and preoperative coronary revascularization might be considered. Whether patients at intermediate risk without ischemic heart disease should be treated with statins and/or beta-blockers is still controversial. In high-risk patients, it is strongly advised to administer beta-blockers with heart rate determined dose adjustment, while the effects of preoperative revascularization remain subject to debate.     

Management der perioperativen Myokardischämie

Patients undergoing vascular surgery are often affected by a much higher cardiac risk profile. Cardiac events in peripheral arterial disease (PAD) patients occur not only more frequently than in non-PAD patients but are also associated with a poorer outcome. Despite a similar underlying pathogenesis, PAD patients receive less pharmaceutical treatment than patients with known coronary artery disease (CAD). If certain risk factors for CAD are present, preoperative cardiology diagnostic testing and if necessary therapy is recommended. When a perioperative myocardial infarction is suspected, an electrocardiogram (ECG) should immediately be carried out. In the case of ST segment elevation myocardial infarction, a percutaneous coronary intervention (PCI) is performed without waiting for the blood test results. If a non-ST segment elevation myocardial infarction is present, further evaluation includes (serial) blood tests for troponin, a cardiac biomarker. In addition to a type 1 myocardial infarction, which is caused by rupture of plaque, a type 2 myocardial infarction must also be taken into consideration, which can arise due to an imbalance between oxygen needs and increased consumption even in the absence of plaque rupture (e.g. in cases of significant coronary artery stenosis and coronary artery spasm). Coronary angiography is performed on an individual basis depending on the risk-benefit assessment. Medicinal therapy of myocardial infarction includes dual platelet inhibition and anticoagulation. Other potentially life-threatening diseases, such as pulmonary embolism and aortic dissection have to be taken into account as differential diagnoses in acute situations.     

Indications for electrocardiogram in the preoperative assessment for programmed surgery

OBJECTIVES: To establish indications for ordering a screening electrocardiogram (ECG) before scheduled surgery. To study the prevalence of abnormalities found in routine ECGs and the impact of routine ECGs on anesthetic and surgical management and on preventing perioperative complications. MATERIAL AND METHODS: A prospective study of 413 patients undergoing scheduled non-cardiac surgery over a two-year period. ECG anomalies were defined as major or minor in function of their association with perioperative morbimortality. ECG results were considered expected or unexpected in function of agreement with a patient's history. RESULTS: An ECG was done for all patients before surgery. Anomalies were observed in 41.9% of the ECGs, 28.6% of which were considered major. The prevalence of anomalies was greater among men over 40 years of age, with heart or respiratory disease and these classified as ASA III-V. The anomalies were unexpected in 8.9% and did not cause postponement or cancellation of scheduled procedures. Anomalies found led to changes in preoperative approach in 0.5% of the cases. Intraoperative complications were seen in 7.9% and postoperative complications in 24.6%. CONCLUSIONS: Preoperative ECGs should be obtained only in patients over 40 years of age who present cardiac or respiratory signs or symptoms and who are diagnosed of some heart or respiratory disease.     

Surgery for esophageal cancer complicate with cardiovascular disease

A risk of cardiac complications is one of the most significant risks to patient undergoing major surgery. Especially, for the patients with cancer, the preoperative management can be complex. The direct effect of cancer and side effect of prior chemotherapy or radiation therapy should be considered. The 2007 American College of Cardiology/American Heart Association( ACC/AHA) guidelines on perioperative cardiovascular evaluation for noncardiac surgery concluded that 3 elements must be assessed to determine the risk of cardiac event. The preoperative risk in a patient is initially assessed by the presence or absence of clinical predictors of increased perioperative cardiovascular risk, the patient's level of cardiac function, and the underlying risk of the surgical procedure. Here we will provide an overview of issue that are relevant to patients with esophageal cancer.     

Preoperative cardiac risk assessment: an updated approach.

HYPOTHESIS: We provide an updated algorithm for approaching preoperative cardiac risk assessment in patients undergoing noncardiac surgery. DESIGN: A National Library of Medicine PubMed literature search was performed dating back to 1985 using the keywords "preoperative cardiac risk for noncardiac surgery." This search was restricted to English language articles involving human subjects. RESULTS: Patient-specific and operation-specific cardiac risk can be determined clinically. Patients with major cardiac risk factors have a high incidence of perioperative cardiac complications, whereas the risk is less than 3% for low-risk patients. For intermediate-risk patients, no prospective randomized studies demonstrate the efficacy of noninvasive stress testing (dipyridamole thallium or dobutamine echocardiography) or of subsequent coronary revascularization for preventing perioperative cardiac complications. Recent studies demonstrate that perioperative beta-blockade significantly reduces the adverse cardiac event rate in intermediate-risk patients. CONCLUSIONS: Most patients with high cardiac risk should proceed with coronary angiography. Patients with low cardiac risk can proceed to surgery without noninvasive testing. For intermediate-risk patients, consideration may be given to further stress testing prior to surgery; however, in most patients, proceeding to surgery with perioperative beta-blockade is an acceptable alternative.     

An unexpected left atrial cavernous hemangioma: the cardiac surgeon needs an optimal preoperative study!

An optimal preoperative evaluation is fundamental to the assessment of all patients undergoing cardiac surgery. We report the case of a male patient who underwent elective coronary artery bypass surgery, and intraoperative transesophageal echocardiography (TEE) revealed an unexpected left atrial cavernous hemangioma. The tumor was resected via a transatrial approach, and a definitive diagnosis was made after histological examination. This uncommon intra-atrial tumor (which accounts for approximately 2.8% of all benign cardiac neoplasms) was detected at the time of the operation as no basic echocardiography study had been performed on the patient during the process of diagnosing his coronary heart disease because of a suboptimal cardiological work-up. Most cardiac masses are discovered incidentally by imaging techniques; in this patient, transthoracic echocardiography could have aided in the preoperative study and enabled the cardiac surgeon to plan and perform the adequate surgical procedure beforehand. Intraoperative TEE should be used routinely in all patients undergoing cardiac surgery: the clinical information obtained in certain cases might have a direct impact on surgical decision-making and might therefore positively influence patient's outcome.     

Diagnostische Abklärung des akuten Koronarsyndroms bei älteren Patienten in der Notaufnahme

Diagnostic algorithm in the emergency department

Elderly patients admitted to hospital with acute chest pain must be investigated in a timely and structured manner. The evaluation of an acute coronary syndrome includes a physical examination, recording of a 12-lead electrocardiogram (ECG), measurement of cardiac biomarkers, usually of troponin T or I and an echocardiographic examination in addition to the past medical history. The evaluation is frequently followed by an observation period with monitoring of ECG and troponin and possibly by a stress test.

Diagnosis

With consideration of all findings the diagnosis of an acute myocardial infarction can be made. The diagnosis among elderly patients is frequently difficult as they often exhibit atypical complaints. Patients who are at high or intermediate risk for future cardiovascular events should undergo an invasive evaluation. Low-risk patients have a favorable prognosis and can be treated as outpatients. This article provides an overview on the diagnosis of acute coronary syndrome in elderly patients.     

Value of preoperative screening studies

In order to develop a sensitive and economically reasonable preoperative screening program capable of identifying perioperative risk factors, we performed a prospective study on patients scheduled for elective urological surgery. According to age, 379 patients were assigned to six groups. After the history and physical examination had been completed the attending anesthesiologist classified the patient's anesthetic risk according to ASA criteria. Furthermore, based on his clinical impression he ordered an individual set of screening parameters (laboratory tests, X-ray films, electrocardiography (ECG), and other appropriate diagnostic procedures) to be done. This "individual" screening and its results were compared with the results of the larger "routine" preoperative screening program performed independently of the study for all patients. All cases were then followed up in order to document perioperative complications. We were thus, able to recognize risk-identifying screening parameters resp. pathological findings missed by the "individual" screening. Laboratory tests from the nonselective "routine" screening yielded pathological results in a relatively high percentage of 31.4% of cases. ECG alterations or chest X-ray findings relevant to the patient's anesthetic management were present in 26.1% resp. 13.6%. Observations missed by the "individual" screening, though important for the prevention of perioperative complications, were pathological ECGs in only 1.9% of all cases. An influence of patient age on the frequency of pathological screening results and perioperative complications could be shown. Laboratory tests, chest X-rays and additional diagnostic procedures should be restricted to patients with pathological results or physiological examination. Our results underline once more the importance of a carefully taken history, a meticulous physical examination and the preoperative performance of an ECG for patients of every age scheduled for anesthesia and surgery.     

Incidencia de alteraciones electrocardiográficas en el preoperatorio de cirugía no cardiaca

BackgroundThe electrocardiogram is the most widely used test to assess cardiovascular risk during the preoperative period.The objective of the present study is to evaluate the incidence of electrocardiographic alterations in the general population scheduled for non-cardiac surgery and to determine if the age greater than or equal to 65 years or the revised cardiac risk index ≥ 1 represent a risk factor for presenting these alterations.Material and methodsOver a period of one month, all preoperative electrocardiograms (ECG) from the anesthesia clinic were analyzed. Various epidemiological data were collected and the revised cardiac risk index was calculated. Major alterations were defined as those requiring Cardiology follow-up.Results476 patients were recruited, of whom 40.8% were ≥ 65 years, 32.6% had HTN, 14.4% DM and 27.9% dyslipidemia. 16.16% of the patients had a Lee Index ≥ 1.Of the entire sample, 80.5% had a normal ECG, 6.5% minor alterations and 13.0% major alterations.In the multivariate analysis, age ≥ 65 years and the presence of HTN were shown as independent risk factors for presenting alterations in the total and major ECG.The Lee index ≥ 1 was not associated with an increased risk of electrocardiographic abnormalities.ConclusionsPatients ≥ 65 years old and those with HTN are at greater risk of presenting major electrocardiographic abnormalities, so we recommend including the ECG as a routine diagnostic test in the preoperative period of non-cardiac surgery.     

Cardiac complications after elective major vascular surgery

Cardiac complications are the major cause of perioperative and late mortality and morbidity in patients undergoing elective major vascular surgery. This review focuses on the pathophysiology of perioperative complications, risk assessment and risk reduction strategies, all related to cardiovascular disease. Patients without cardiac risk factors are considered to be at low risk and no additional evaluation for coronary artery disease is recommended; β-adrenergic blockers may reduce perioperative cardiac events; patients with one or more risk factors represent an intermediate to high-risk population. β-Adrenergic blockers should be prescribed to all patients and coronary revascularization should be reserved for patients who have a clearly defined need for revascularization independent of the need for vascular surgery.     

Pre-operative electrocardiograph examination.

The leading cause of death following surgery is a cardiac event, and an electrocardiogram is the most common pre-operative test to investigate coronary artery disease. Fifty adults, who required an electrocardiogram, undergoing general surgical procedures, were recruited into this pilot study, which investigated the examination rate of electrocardiographs by doctors pre-operatively. Each tracing was folded in one corner and a paperclip prevented full pre-operative viewing without its removal. Results suggest that 30% of ECGs were not opened and the records of 58% patients overall had no mention of the ECG having been performed. Further analysis showed no correlation with the examination rate of the electrocardiograph with patient age or fitness. If this reflects normal clinical practice, it is sub-optimal use of resources and warrants further audit.     

Preoperative evaluation using asialoscintigraphy in patients undergoing cardiac surgery with noncardiac liver cirrhosis

Objective Liver cirrhosis is recognized as one of the risk factors for severe complications after cardiac surgery. However, there are no established methods for risk stratification of the patients with liver cirrhosis (LC) regarding cardiac surgery. We present our experience of preoperative evaluation of liver function using asialoscintigraphy. Methods Between April 1999 and December 2005, we evaluated preoperative liver function using asialoscintigraphy with technetium-99m galactosyl human serum albumin in four cirrhotic patients undergoing coronary artery bypass grafting (n = 2) and valve replacement (n = 2), whose etiologies of LC were alcoholabuse (n = 1) and hepatitis C virus infection (n = 3). They also underwent other tests for preoperative evaluation of liver function, including the indocyanine green (ICG) test. Results Asialoscintigraphy revealed that the receptor index and the index of blood clearance in each patient were 0.81/0.73, 0.95/0.5, 0.82/0.62, and 0.97/0.57, respectively. These values closely correlated with the results of the ICG test. All patients were discharged alive from hospital after surgery. However, although one patient who underwent off-pump bypass had an uneventful course, three patients had major complications: pleural effusion (n = 1) and wound infection (n = 2). Conclusion Asialoscintigraphy is a practical, reliable method that can replace the ICG test for estimating hepatic function for risk stratification of cirrhotic patients undergoing cardiac surgery, whose mortality and morbidity are still high.     

Electrocardiographic exercise stress testing for cardiac risk assessment in patients undergoing noncardiac surgery

BACKGROUND: The value of exercise electrocardiography in the prediction of perioperative cardiac risk has yet to be defined. This study was performed to determine the predictive value of exercise electrocardiography as compared with clinical parameters and resting electrocardiography. METHODS: A total of 204 patients at intermediate risk for cardiac complications prospectively underwent exercise electrocardiography before noncardiac surgery. Of these, 185 were included in the final evaluation. All patients underwent follow-up evaluation postoperatively by Holter monitoring for 2 days, daily 12-lead electrocardiogram, and creatine kinase, creatine kinase MB, and troponin-T measurements for 5 days. Cardiac events were defined as cardiac death, myocardial infarction, minor myocardial cell injury, unstable angina pectoris, congestive heart failure, and ventricular tachyarrhythmia. Potential risk factors for an adverse event were identified by univariate and multivariate logistic regression analysis. RESULTS: Perioperative cardiac events were observed in 16 patients. There were 6 cases of myocardial infarction and 10 cases of myocardial cell injury. The multivariate correlates of adverse cardiac events were definite coronary artery disease (odds ratio, 8.8; 95% confidence interval [CI], 1.1--73.1; P = 0.04), major surgery (odds ratio, 4.7; 95% CI, 1.3--16.3; P = 0.02), reduced left ventricular performance (odds ratio, 2.0; 95% CI, 1.1--3.8; P = 0.03), and ST-segment depression of 0.1 mV or more in the exercise electrocardiogram (odds ratio, 5.2; 95% CI, 1.5--18.5; P = 0.01). A combination of clinical variables and exercise electrocardiography improved preoperative risk stratification. CONCLUSIONS: This prospective study shows that a ST-segment depression of 0.1 mV or more in the exercise electrocardiogram is an independent predictor of perioperative cardiac complications.     

Anaesthesia for abdominal aortic surgery — a review (Part II)

Patients presenting for abdominal aortic surgery have a high incidence of vascular disease elsewhere, manifested primarily by hypertension, coronary and cerebrovascular disease, as well as co-existing respiratory, renal and metabolic disorders. Routine clinical assessment, electrocardiogram, chest roentgenograms, resting and exercise radionuclide ventriculography and echocardiography, dipyrdiamole-thallium scanning are all designed to assess the functional status of the myocardium and to detect the presence of significant coronary artery disease. Patients with no abnormalities on physical examination, routine evaluation and no redistribution on dipyridamole-thallium scanning should proceed to surgery with the expectation of very low perioperative cardiac risk. Patients with evidence of coronary artery disease and significant redistribution on dipyridamole-thallium scan should undergo coronary angiography and possible myocardial revascularization before definitive aortic vascular surgery. For high cardiac risk patients with no bypassable lesions presenting for abdominal aortic aneurysm resection a conservative policy of serial three monthly ultrasound or CT assessment may be adopted, with selective resection for rapid aneurysm expansion or symptom development. A variety of extra-anatomical and angioplastic techniques is available for similar high cardiac risk patients with aortoiliac occlusive disease. The haemodynamic consequences of aortic cross-clamping, especially in aneurysm patients, include a significant reduction in stroke volume, cardiac index, and myocardial oxygen consumption with an increased systemic vascular resistance. Patients with coronary artery disease may respond to aortic cross-clamping by increasing pulmonary capillary wedge pressure and by demonstrating ECG evidence of myocardial ischaemia. Pulmonary artery catheterization is especially indicated in patients with a history of previous myocardial infarction, angina or signs of cardiac failure and in patients with evidence of diminished ejection fraction, abnormal ventricular wall motion or myocardial redistribution on preoperative scanning. The more widespread application of intraoperative transoesophageal two-dimensional echocardiography and radionuclide cardiography monitoring techniques into anaesthetic practice will enable measurement of left ventricular dimensions, myocardial performance and wall motion. Suggested guidelines for anaesthetic management are presented in Table VI. A combined opiate-oxygen-volatile anaesthetic agent technique will best ensure a hypodynamic circulation with preservation of myocardial oxygenation.(ABSTRACT TRUNCATED AT 400 WORDS)     

Preoperative cardiac evaluation for noncardiac surgery: a functional approach.

The preoperative assessment of the high risk patient undergoing noncardiac surgery has traditionally been based on history, physical examination, and preoperative testing. We propose a method of assessing preoperative risk based on the presentation of coronary artery disease, exercise tolerance, and extent of the surgical procedure. Since this is an evolving field, as new information and perioperative management techniques become available, the preoperative evaluation of the high risk patient will change. We have presented one approach based on our interpretation of data from the current anesthesiology and cardiology literature. In the patient with a recent MI, the predischarge symptom-limited stress test and the electrocardiographic classification can be used to better stratify risk. In the patient with angina, testing should be reserved for those patients who are candidates for coronary revascularization or alternative surgical procedures. In the patient at risk of but without overt symptoms of coronary artery disease, the number of clinical risk factors can determine the probability of coronary artery disease in the individual patient. The decision to perform preoperative revascularization should be based on its anticipated improvement of both the short- and long-term prognosis of the patient considering the risk of such procedures. The objective assessment of LVEF should be performed in patients with a poor exercise tolerance with either a high risk of perioperative ischemia or a suspicion of cardiomyopathy.     

Multicenter study of cardiac events and anesthetic management of patients with ischemic heart diseases undergoing noncardiac surgery

We designed a joint research project to investigate the incidence of ischemic heart diseases in patients undergoing noncardiac surgery and to define the risk of perioperative cardiac complications in these patients. Of the 8358 surgical patients in the 8 departments of anesthesiology between March 1997 and June 1997, 328 (3.9%) had ischemic heart diseases. Among the 328 patients, 54 (16.4%) developed perioperative cardiac events, including myocardial infarction (3 patients) and either lethal or potentially dangerous dysrhythmias (51 patients). Preoperative cardiac assessments were performed while the anesthetic techniques including intensive monitoring and perioperative prophylactic therapy were also employed. Patients with ischemic heart diseases received various types of preoperative evaluation to identify the degree of coronary artery disease and to assess the overall cardiac function. The patients were monitored using a multilead electrocardiogram, an arterial line, a central venous catheter, a pulmonary artery catheter, and by transesophageal echocardiography intraoperatively. Therapeutically, isosorbide, nitroglycerin, beta-blockers, calcium channel blockers, and/or nicorandil were administered to prevent perioperative ischemia. So far, no generally accepted management strategies have been established in patients with cardiovascular disorders based on large-scale outcome trials in Japan. Therefore, nationwide large multicenter trials are awaited with interest in order to establish helpful guidelines to improve the perioperative management and to reduce ischemia in cardiac patients undergoing noncardiac surgery.     

Der Stellenwert der Echokardiographie in der präoperativen Diagnostik bei kardialen Risikopatienten vor nicht-herzchirurgischen Eingriffen

Echocardiography is a noninvasive method for cardiac evaluation. A review of the current literature shows that the routine use of echocardiography for assessing perioperative cardiac risk in patients undergoing noncardiac surgery can not be supported. Only patients with suspected relevant heart valve diseases, acute heart failure, cardiomyopathy or condition after heart or heart-lung transplantation may benefit from preoperative echocardiography. In patients with suspected or proven coronary artery disease stress echocardiography offers the most relevant additional information for the anaesthesiologist. However, because of the high financial and personal implications it should be reserved to those patients who are not able to perform a normal stress test. Besides in patients in whom transthoracic echocardiography doesn’t offer sufficient information or is not possible transesophageal echocardiography plays only a minor role in preoperative cardiac evaluation.     

Prävention perioperativer Myokardischämien – ein Update

Perioperative cardiac morbidity and mortality are a major health care challenge with important individual as well as economic aspects. Up to 30% of all perioperative complications and up to 50% of all postoperative deaths are related to cardiac causes. Perioperative myocardial ischemia, which occurs in more than 40% of patients with or at risk for coronary artery disease and undergoing noncardiac surgery, represents a dynamic predictor of postoperative cardiac complications. Long-duration myocardial ischemia and ischemic episodes associated with myocardial cell damage are particularly of prognostic relevance. In patients suffering from this type of ischemia, the incidence of adverse cardiac outcome is increased up to 20-fold. Reducing the incidence of perioperative myocardial ischemia is associated with a decrease in adverse cardiac outcome. Important issues related to perioperative myocardial ischemia are hematocrit level, body temperature, and hemodynamic variables. In contrast, the choice of anesthetic agents and techniques appears to be less important. Perioperative administration of anti-ischemic drugs in patients at risk, however, leads to a further decrease in the incidence of myocardial ischemia and to an improvement in patient outcome. Recent studies suggest that alpha 2-agonists and particularly beta-adrenoreceptor blocking agents are effective anti-ischemic drugs in the perioperative setting. Perioperative administration of beta-adrenoreceptor blocking agents in coronary risk patients undergoing noncardiac surgery is associated with a reduced rate of postoperative cardiac complications and an improvement in long-term outcome. This is particularly relevant in high risk patients with preoperative stress-induced ischemic episodes. In clinical practice, therefore, chronically administered anti-ischemic drugs should also be administered on the day of surgery and during the postoperative period. In untreated patients with or at risk for coronary artery disease and who have to undergo urgent surgical procedures without the opportunity of preoperative anti-ischemic intervention, perioperative administration of beta-adrenoreceptor blocking agents is mandatory.