Evaluation of chest pain in the emergency department

Chest Pain as a Manifestation of Intracranial Hypotension: Report of Four Cases

BACKGROUND

Chest pain has not been recognized as a manifestation of intracranial hypotension secondary to cerebrospinal fluid leakage.

CASE REPORT

We report on 4 patients with intracranial hypotension diagnosed by the pattern of headaches, temporal proximity to dural puncture, magnetic resonance imaging findings, and resolution of symptoms after epidural blood patch who presented with chest pain. The chest pain was episodic, located in the sternal and interscapular region for the first 3 patients, with no radiation to any other region and no clear relationship to exertion. The fourth patient had episodic chest pain located in the subclavicular and suprascapular region. Two patients reported dyspnea with chest pain. Underlying coronary artery ischemia was excluded using a combination of the electrocardiogram and cardiac enzyme assays. The pain resolved after epidural blood patch treatment. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Clinicians should be aware of chest pain that can be seen with intracranial hypotension and cerebrospinal leakage to ensure appropriate diagnostic tests and treatment.

Importance of hospital entry: walk-in STEMI and primary percutaneous coronary intervention

INTRODUCTION

Patients with ST elevation myocardial infarction (STEMI) require rapid identification and triage to initiate reperfusion therapy. Walk-in STEMI patients have longer treatment times compared to emergency medical service (EMS) transported patients. While effective triage of large numbers of critically ill patients in the emergency department is often cited as the reason for treatment delays, additional factors have not been explored. The purpose of this study was to evaluate baseline demographic and clinical differences between walk-in and EMS-transported STEMI patients and identify factors associated with prolonged door to balloon (D2B) time in walk-in STEMI patients.

METHODS

We performed a retrospective review of 136 STEMI patients presenting to an urban academic teaching center from January 2009 through December 2010. Baseline demographics, mode of hospital entry (walk-in versus EMS transport), treatment times, angiographic findings, procedures performed and in-hospital clinical events were collected. We compared walk-in and EMS-transported STEMI patients and identified independent factors of prolonged D2B time for walk-in patients using stepwise logistic regression analysis.

RESULTS

Walk-in patients (n=51) were more likely to be Latino and presented with a higher heart rate, higher systolic blood pressure, prior history of diabetes mellitus and were more likely to have an elevated initial troponin value, compared to EMS-transported patients. EMS-transported patients (n=64) were more likely to be white and had a higher prevalence of left main coronary artery disease, compared to walk-in patients. Door to electrocardiogram (ECG), ECG to catheterization laboratory (CL) activation and D2B times were significantly longer for walk-in patients. Walk-in patients were more likely to have D2B time >90 minutes, compared to EMS- transported patients; odds ratio 3.53 (95% CI 1.03, 12.07), p=0.04. Stepwise logistic regression identified hospital entry mode as the only independent predictor for prolonged D2B time.

CONCLUSION

Baseline differences exist between walk-in and EMS-transported STEMI patients undergoing primary percutaneous coronary intervention (PCI). Hospital entry mode was the most important predictor for prolonged treatment times for primary PCI, independent of age, Latino ethnicity, heart rate, systolic blood pressure and initial troponin value. Prolonged door to ECG and ECG to CL activation times are modifiable factors associated with prolonged treatment times in walk-in STEMI patients. In addition to promoting the use of EMS transport, efforts are needed to rapidly identify and expedite the triage of walk-in STEMI patients.

ACR Appropriateness Criteria(®) acute nonspecific chest pain-low probability of coronary artery disease

This document outlines the usefulness of available diagnostic imaging for patients without known coronary artery disease and at low probability for having coronary artery disease who do not present with classic signs, symptoms, or electrocardiographic abnormalities indicating acute coronary syndrome but rather with nonspecific chest pain leading to a differential diagnosis, including pulmonary, gastrointestinal, or musculoskeletal pathologies. A number of imaging modalities are available to evaluate the broad spectrum of possible pathologies in these patients, such as chest radiography, multidetector CT, MRI, ventilation-perfusion scans, cardiac perfusion scintigraphy, transesophageal and transthoracic echocardiography, PET, spine and rib radiography, barium esophageal and upper gastrointestinal studies, and abdominal ultrasound. It is considered appropriate to start the assessment of these patients with a low-cost, low-risk diagnostic test such as a chest x-ray. Contrast-enhanced gated cardiac and ungated thoracic multidetector CT as well as transthoracic echocardiography are also usually considered as appropriate in the evaluation of these patients as a second step if necessary. A number of rest and stress single-photon emission CT myocardial perfusion imaging, ventilation-perfusion scanning, aortic and chest MR angiographic, and more specific x-ray and abdominal examinations may be appropriate as a third layer of testing, whereas MRI of the heart or coronary arteries and invasive testing such as transesophageal echocardiography or selective coronary angiography are not considered appropriate in these patients. Given the low risk of these patients, it is mandated to minimize radiation exposure as much as possible using advanced and appropriate testing protocols. The ACR Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Diagnostic performance of initial salivary alpha-amylase activity for acute myocardial infarction in patients with acute chest pain

BACKGROUND

To rule out acute myocardial infarction (AMI) in chest pain patients constitutes a diagnostic challenge to emergency department (ED) physicians.

STUDY OBJECTIVES

To evaluate the diagnostic value of measuring salivary alpha-amylase (sAA) activity for detecting AMI in patients presenting to the ED with acute chest pain.

METHODS

sAA activity was measured in a prospective cohort of 473 consecutive adult patients within 4 h of onset of chest pain. Comparisons were made between patients with a final diagnosis of AMI and those with non-AMI. Univariate analysis and multiple logistic regression model were used to identify independent clinical predictors of AMI.

RESULTS

Initial sAA activity in the AMI group (n = 85; 266 ± 127.6 U/mL) was significantly higher than in the non-AMI group (n = 388; 130 ± 92.8 U/mL, p < 0.001). sAA activity levels were also significantly higher in patients with ST elevation AMI (n = 53) compared to in those with non-ST elevation AMI (n = 32) (300 ± 141.1 vs. 210 ± 74.1 U/mL, p < 0.001). The area under the receiver operating characteristic curve of sAA activity for predicting AMI in patients with acute chest pain was 0.826 (95% confidence interval [CI] 0.782-0.869), with diagnostic odds ratio 10.87 (95% CI 6.16-19.18). With a best cutoff value of 197.7 U/mL, the sAA activity revealed moderate sensitivity and specificity as an independent predictor of AMI (78.8% and 74.5%).

CONCLUSIONS

High initial sAA activity is an independent predictor of AMI in patients presenting to the ED with chest pain.

Acute coronary syndrome critical pathway: chest PAIN caremap: a qualitative research study--provider-level intervention

Recently published data on healthcare performance continue to show a substantial gap between evidence-based guidelines and management of patients in real-world settings. This article describes an operational model that will be used to test whether a critical pathway applied in a secondary care-level institution may improve the process of care related to acute coronary syndromes (ACS). We have developed the pathway for management of all patients who present to our emergency department with a chief complaint of acute chest pain. Based on individual immediate ischemic event risk, patients are categorized according to a prespecified algorithm under the acronym of "PAIN" (P-Priority risk, A-Advanced risk, I-Intermediate risk, and N-Negative/low risk) as prespecified in an algorithm. Along with the algorithm come 2 detailed order sets, 1 for ST-elevation ACS and another for non ST-elevation ACS. The pathway, together with the 2 order sets, are color-coded with the "PAIN" acronym (P-red, A-yellow, I-yellow, N-green) that will guide patient management according to his or her risk stratification. These colors, similar to the road traffic light code, have been chosen as an easy reference for the provider about the sequential risk level of patients with ACS. This experimental model intends, with its unique structured approach, to increase awareness and improve adherence to the published American Heart Association/American College of Cardiology guidelines for the management of ACS.

In search of the best method to predict acute coronary syndrome using only the electrocardiogram from the emergency department

INTRODUCTION

The aim of this study was to compare different methods to predict acute coronary syndrome (ACS) using only data from a single electrocardiogram (ECG) in the emergency department (ED).

METHOD

We compared the ACS prediction abilities of classical ECG criteria, human expert ECG interpretation, a logistic regression model and an artificial neural network ensemble (ANN). The ED ECG and discharge diagnoses were retrieved for 861 patient visits to the ED for chest pain. Cross-validation was used to estimate the generalization performance of the logistic regression and the ANN model.

RESULTS

The logistic regression model had the overall best performance in predicting ACS with an area under the receiver operating characteristic curve of 0.88. The sensitivities of logistic regression, ANN, expert physicians, and classical ECG criteria were 95%, 95%, 82%, and 75%, respectively, and the specificities were 54%, 44%, 63%, and 69%.

CONCLUSION

Our logistic regression model was the best overall method to predict ACS, followed by our ANN. Decision support models have the potential to improve even experienced ECG readers' ability to predict ACS in the ED.

Association between subjective descriptors of coronary pain and disease characteristics: A pilot study in a Hellenic rural population

PURPOSE

We explored whether the way Hellenic patients describe their cardiac chest pain (verbal descriptions of the nature, intensity, temporal quality, location and radiation) associates with the diagnosis [acute myocardial infarction (AMI) versus unstable angina (UA)] as well as with the location of the coronary lesions.

METHODS

A cross-sectional correlational design was employed to study 80 consecutive coronary care patients (44 with AMI, 36 with UA) from northwestern Hellas.

RESULTS

Pain intensity did not differ significantly between AMI and UA, in contrast to treatment-seeking behaviour and accompanying symptoms (p< or =0.03). Of AMI patients, women used more often the word "pain" (p=0.011), and indicated pain at the left shoulder (p=0.004). AMI patients used fewer words (p=0.03), and experienced pain at the back of the neck (p=0.03) and of the left arm (p=0.02) less often. The descriptions "knob", "constriction" and "drill" were more prevalent in UA patients (p<0.01). The description "drill" discriminated between diagnostic groups in a multivariate model (p=0.03). Associations between the infarct and pain location (p< or =0.03), and the use of some sensory descriptors (p< or =0.02) were detected. Pain locations associated with ECG findings (p< or =0.005).

CONCLUSIONS

Subjective acute coronary pain descriptions and pain characteristics may associate with the pathophysiological processes in coronary syndromes.

Gastric perforation secondary to incarcerated hiatus hernia: an important differential in the diagnosis of central crushing chest pain

Gastric perforation in association with incarceration of a hiatus hernia rarely features on a list of differential diagnoses of acute chest pain. A patient presented to the emergency department with acute chest pain characteristic of myocardial ischaemia. Several risk factors for ischaemic heart disease (IHD) were present. Investigations revealed normal cardiac enzymes and normal electrocardiography both initially and at 90 mins. A chest radiograph demonstrated the presence of a hiatus hernia. The patient was diagnosed with, and treated for, unstable angina. A troponin T test at 12 h post-admission was normal. The patient's clinical condition continued to deteriorate. The source of her pain was found to be gastric perforations in association with an incarcerated hiatus hernia. Her postoperative course was complicated by pulmonary and intra-abdominal sepsis necessitating admission to the intensive care unit where she remained for 23 days. This case highlights the challenge that non-cardiac chest pain presents to the acute care physician. Patients who present with risk factors for and symptoms consistent with a diagnosis of IHD may have non-cardiogenic pathology which can be life-threatening.

Efficiency and cost saving of 7 day per week exercise testing utilizing all electrocardiography technologists

BACKGROUND

In most centers, exercise testing (ET) is performed by one or two trained technologists during the weekdays (0800 hours-1600 hours), leaving a void during evenings and weekends. This leads to unnecessary increased costs due to delays in management of patients. Electrocardiography technologists (ECGT) are often available for extended hours. This project was undertaken to improve the efficiency of the ET laboratory by using ECGT to perform ET during these extended hours.

METHODS

Clinical utility and cost saving of a 7 day per week ET for management of patients with suspected and/or known coronary artery disease utilizing ECGT was assessed after adequate training. Of 4099 patients undergoing ET between January 1995 and December 1997, 810 tests performed by ECGT were reviewed retrospectively.

RESULTS

Of the 810 patients (age mean 58.4 +/- 0.44 yrs; range 16-88; males: 508, females: 302), 806 (99.5%) underwent the Bruce protocol. The indications were: diagnostic, 61.3%, predischarge acute myocardial infarction (AMI), 17.7%, evaluation of angina, 19.6%, other, 1.4%. Only 8 (0.1%) patients had complications (prolonged chest pain, 6; nonsustained ventricular tachycardia, 2) with no AMIs or deaths. This strategy resulted in a savings of 158 bed days (Can189,600 dollars) on inpatients and 15 bed days (Can18,000 dollars) on those presenting to the emergency department.

CONCLUSIONS

This study demonstrates the feasibility and safety of utilizing ECGT for ET thus extending the hours of service. This resulted in efficient patient management, with a considerable cost-saving to the hospital.

Right precordial leads and lead aVR at exercise electrocardiography: does it change test results?

BACKGROUND

A recent study on exercise testing (ET) suggested that ST-segment changes in the right precordial leads (RPL) may increase its sensitivity substantially. However, this study looked at a highly selected population of patients who all underwent thallium-201 scintigraphy and coronary angiography. The present study evaluated the clinical utility of ST-segment changes in the RPL and lead aVR in an unselected population of patients undergoing ET.

METHODS

A total of 906 consecutive patients who received ET were included in the study. ET was done using the Bruce Protocol with a 12-lead electrocardiogram (ECG) substituting V(4)R and V(6)R for V(1) and V(6). Leads V(1) and V(6) were selected for omission as these two leads hardly ever manifest changes in isolation. Substituting two leads would obviate the need for a more complex recording system, thus improving clinical utility.

RESULTS

On the basis of horizontal/downsloping ST-segment depression (STD) of 1.0 mm or more (the usually accepted criterion for a positive ET), 159 (17.5%) patients had a positive ET. In those patients with a negative ET (545 patients), 4 patients (0.7%) manifested STD and 5 patients (0.9%) manifested ST-segment elevation (STE) in leads V(4)R and/or V(6)R, respectively. Of note, 44.7% of the positive ET group had STE in lead aVR.

CONCLUSION

The use of ST-segment changes in RPL during exercise stress testing does not appreciably change the test results of a standard ET. If one was to consider an additional marker, STE in aVR may be more useful, as it shows a stronger correlation with positive tests and does not require the recording of additional leads.

Chest pain unit concept: rationale and diagnostic strategies

Each year in the United States, over 8 million patients present to the emergency department(ED) with complaints of chest discomfort or other symptoms consistent with possible acute coronary syndrome (ACS). While over half of these patients are typically admitted for further diagnostic evaluation, fewer than 20% are diagnosed with ACS. With hospital beds and inpatient resources scarce, these admissions can be avoided by evaluating low- to moderate-risk patients in chest pain units. This large, undifferentiated patient population represents a potential high-risk group for emergency physicians requiring a systematic approach and specific ED resources. This evaluation is required to appropriately determine if a patient is safe to be discharged home with outpatient follow-up versus requiring admission to the hospital for monitoring and further testing.

Exercise testing in chest pain units: rationale, implementation, and results

Chest pain units are now established centers for assessment of low-risk patients presenting to the emergency department with symptoms suggestive of acute coronary syndrome. Accelerated diagnostic protocols, of which treadmill testing is a key component, have been developed within these units for efficient evaluation of these patients. Studies of the last decade have established the utility of early exercise testing,which has been safe, accurate, and cost-effective in this setting. Specific diagnostic protocols vary, but most require 6 to 12 hours of observation by serial electrocardiography and cardiac injury markers to exclude infarction and high-risk unstable angina before proceeding to exercise testing. However, in the chest pain unit at UC Davis Medical Center,the approach includes "immediate" treadmill testing without a traditional process to rule out myocardial infarction. Extensive experience has validated this approach in a large, heterogeneous population. The optimal strategy for evaluating low-risk patients presenting to the emergency department with chest pain will continue to evolve based on current research and the development of new methods.

Can symptom presentation predict unstable angina/non-ST-segment elevation myocardial infarction in a moderate-risk cohort?

BACKGROUND

Accurate recognition of acute coronary syndromes (ACS) on initial presentation is key to minimizing morbidity and mortality. The wide spectrum of symptom presentation in ACS complicates recognition. Unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI) may be particularly difficult to diagnose as patients often do not exhibit initial high-risk features, leaving the clinician with symptom presentation alone, on which to base decisions regarding further investigation and treatment.

PURPOSE

The aim of this study was to compare typical symptom presentation (classic description of angina) and atypical presentation in a cohort presenting with symptoms suggestive of UA/NSTEMI.

METHOD

A prospective cohort design was used to evaluate 100 patients enrolled in an Emergency Department Chest Pain Program.

RESULTS

Although patients with typical presentation were more likely to have UA/NSTEMI, atypical presentation did not rule out this diagnosis. Of the 31 patients with UA/NSTEMI, most (n=23, 74.2%) had atypical symptoms. Male gender, symptom location, and history of ischemic heart disease were significantly associated with UA/NSTEMI. Of those with a final diagnosis of UA/NSTEMI, there was no difference in symptom presentation based on age or gender.

CONCLUSION

Clinicians should not rely on classic descriptions of angina when evaluating patients suspected of UA/NSTEMI.

Role of "Ischemia modified albumin", a new biochemical marker of myocardial ischaemia, in the early diagnosis of acute coronary syndromes

BACKGROUND

Diagnosis of cardiac ischaemia in patients attending emergency departments (ED) with symptoms of acute coronary syndromes is often difficult. Cardiac troponin (cTn) is sensitive and specific for the detection of myocardial damage but may not rise during reversible myocardial ischaemia. Ischemia Modified Albumin (IMA) has recently been shown to be a sensitive and early biochemical marker of ischaemia.

METHODS AND RESULTS

This study evaluated IMA in conjunction with ECG and cTn in 208 patients presenting to the ED within three hours of acute chest pain. At presentation, a 12-lead ECG was recorded and blood taken for IMA and cardiac troponin T (cTnT). Patients underwent standardised triage, diagnostic procedures, and treatment. Results of IMA, ECG, and cTnT, alone and in combination, were correlated with final diagnoses of non-ischaemic chest pain, unstable angina, ST segment elevation, and non-ST segment elevation myocardial infarction. In the whole patient group, sensitivity of IMA at presentation for an ischaemic origin of chest pain was 82%, compared with 45% of ECG and 20% of cTnT. IMA used together with cTnT or ECG, had a sensitivity of 90% and 92%, respectively. All three tests combined identified 95% of patients whose chest pain was attributable to ischaemic heart disease. In patients with unstable angina, sensitivity of IMA used alone was equivalent to that of IMA and ECG combined.

CONCLUSIONS

IMA is highly sensitive for the diagnosis of myocardial ischaemia in patients presenting with symptoms of acute chest pain.

[Value of troponins in acute coronary syndrome in patients with renal failure]

Patients with renal insufficiency can have elevations of serum troponin without suspected clinical coronary ischemia. Although cardiovascular disease is the main cause of death in patients with renal failure, the process of elevation of serum troponin is not well known. Troponin T is more frequently elevated than troponin I in these patients which leads to uncertainty in the clinical interpretation of results. There are studies suggesting that troponin elevations are associated with a higher risk and increased mortality. To explain the process leading to troponin increases in this kind of pathology and to confirm its usefulness in the diagnosis, evolution and prognosis it would be necessary to carry out more clinical studies monitoring troponin and studying the stratification of risk.

Use of an accelerated chest pain assessment protocol in patients at intermediate risk of adverse cardiac events

OBJECTIVE

To determine the feasibility, safety and effectiveness of a structured clinical pathway for stratification and management of patients presenting with chest pain and classified as having intermediate risk of adverse cardiac outcomes in the subsequent six months.

DESIGN

Prospective clinical audit.

PARTICIPANTS AND SETTING

630 consecutive patients who presented to the emergency department of a metropolitan tertiary care hospital between January 2000 and June 2001 with chest pain and intermediate-risk features.

INTERVENTION

Use of the Accelerated Chest Pain Assessment Protocol (ACPAP), as advocated by the "Management of unstable angina guidelines--2000" from the National Heart Foundation and the Cardiac Society of Australia and New Zealand.

MAIN OUTCOME MEASURE

Adverse cardiac events during six-month follow-up.

RESULTS

409 patients (65%) were reclassified as low risk and discharged at a mean of 14 hours after assessment in the chest pain unit. None had missed myocardial infarctions, while three (1%) had cardiac events at six months (all elective revascularisation procedures, with no readmissions with acute coronary syndromes). Another 110 patients (17%) were reclassified as high risk, and 21 (19%) of these had cardiac events (mainly revascularisations) by six months. Patients who were unable to exercise or had non-diagnostic exercise stress test results (equivocal risk) had an intermediate cardiac event rate (8%).

CONCLUSIONS

This study validates use of ACPAP. The protocol eliminated missed myocardial infarction; allowed early, safe discharge of low-risk patients; and led to early identification and management of high-risk patients.

Patients with suspected acute coronary syndrome in a university hospital emergency department: an observational study

BACKGROUND: Improved diagnostics in suspected acute coronary syndrome (ACS) are considered to be needed. To help clarify the current situation and the improvement potential, judged risk in the emergency department (ED) and outcome were analyzed among patients with suspected ACS at a university hospital. METHODS: 157 consecutive patients with symptoms of ACS were included at the ED during 10 days. Risk of ACS was estimated in the ED for each patient based on history, physical examination and ECG by assigning them to one of four risk categories; I (obvious myocardial infarction, MI), II (strong suspicion of ACS), III (vague suspicion of ACS), and IV (no suspicion of ACS). RESULTS: 4, 17, 29 and 50% of the patients were allocated to risk categories I-IV respectively. 74 patients (47%) were hospitalized but only 19 (26%) had ACS as the discharge diagnose. In risk categories I-IV, ACS rates were 100, 37, 12 and 0%, respectively. Of those admitted without ACS, at least 37% could probably, given perfect ED diagnostics, have been immediately discharged. 83 patients were discharged from the ED, and among them there were no hospitalizations for ACS or cardiac mortality at 6 months. Only about three patients per 24 h were considered eligible for a potential ED chest pain unit. CONCLUSIONS: Almost 75% of the patients hospitalized with suspected ACS did not have it, and some 40% of these patients could probably, given perfect immediate diagnostics, have been managed as outpatients. The potential for diagnostic improvement in the ED seems large.

Acute ischemic syndromes. Chest pain center concept

CPCs have been developed to meet the clinical challenge posed by the diverse group of patients presenting to the ED with findings suggestive of a coronary event. Using a protocol-driven approach, high- and low-risk patients can be identified on presentation, facilitating urgent therapy in the former and triage of the latter to more deliberate management. Most CPCs focus on low-risk patients who are being increasingly managed by accelerated diagnostic protocols. These methods comprise systematic strategies that include innovative diagnostic approaches during a 6 to 12 hour period of observation with serial ECGs, continuous monitoring and cardiac biomarker measurements. A negative evaluation is usually followed by predischarge stress testing, and positive findings mandate admission. An essential aspect of the CPC strategy is continuity of care for patients with negative cardiac evaluations. Current data indicate that management of low-risk patients with chest pain in a CPC is safe accurate, and appears to be cost-effective.

Advances create opportunities: implementing the major tenets of the new unstable angina guidelines in the emergency department

Of all the clinical syndromes with which emergency physicians must deal, chest pain of coronary cause has benefited from the most striking recent advances both in diagnostic approach (cognitive and technologic) and in therapeutic options. Chest pain evaluation and management have become important foci of research in emergency medicine, and entire units are dedicated to its clinical prosecution in emergency departments and elsewhere in the hospital. New diagnostic tools are proposed and studied on a regular basis. Antiplatelet, antithrombin, and fibrinolytic agents unknown in clinical practice as recently as 5 years ago have secured places in the emergency physician's armamentarium for treating acute coronary syndrome. Many of these diagnostic and therapeutic tools have been developed in the coronary care unit and in the cardiac catheterization laboratory. Although intuitively they may also be useful outside of those settings, they have unreliably been brought to the ED for implementation and resultant appropriate prompt and early care of the coronary patient who does not meet fibrinolytic criteria. As emergency physicians seek to bring accurate chest pain risk stratification into their practice and begin to use new therapeutic agents to minimize myocardial damage before turning the patient's care over to other specialists, it is essential that they are familiar with the data supporting these approaches. In this commentary, we seek to place the American College of Cardiology/American Heart Association unstable angina guidelines into the clinical context of the ED.

Critical decision making in the management of patients with acute myocardial infarction and other acute coronary syndromes

The decision-making process for emergency physicians in managing patients with signs or symptoms of AMI or unstable angina is quite different than that used by other specialists who might evaluate such patients in a less critical setting (e.g., a cardiologist seeing a private patient in an office or outpatient clinic environment). The emergency physician's evaluation must be highly focused and follow established principles of emergency medicine (Fig. 2). Although the evaluation and treatment of all patients must be individualized to some degree, increasing experience at high-volume centers nationally indicates that well-constructed institutional strategies, protocols, and critical pathways can help emergency physicians to provide consistent, cost-effective management of such patients.

EMERGENCY DEPARTMENT EVALUATION OF THE CHEST PAIN PATIENT

The emergency physician must have a high degree of suspicion for myocardial ischemia in patients presenting with no obvious for their chest pain. The role of the emergency physician is to determine a relative risk for each patient and to order the appropriate studies to minimize the risk of missed myocardial infarction as well as to recognize acute ischemia or infarction and manage it aggressively. It is not possible to rule out myocardial ischemia or infarction subjectively. It is the opinion of these authors that some form of further testing should be performed on patients in all categories, except those determined to be at very low risk.

MEDICOLEGAL ASPECTS OF ACUTE MYOCARDIAL INFARCTION

Emergency physicians face significant liability in the diagnosis and management of patients with acute coronary syndromes. Newer diagnostic and therapeutic modalities continue to add to the tools that assist in sorting through the complexities of this group of patients. Nonetheless, the legal pitfalls continue unabated. Prudent patient care dictates vigilance in recognizing the atypical presentations, streamlining policies and procedures in the ED that impact on the management of these patients, and remembering that managed care policies affect payment, and not patient care.

Chest pain in the emergency department

The assessment of patients with chest pain is challenging for any emergency physician because of the spectrum of illness covered by this symptom. Patients may have a serious life-threatening condition or a trivial self-limiting illness. This article presents an approach to the assessment and early management of patients presenting with acute non-traumatic chest pain in the emergency department.

[Acute precordial pain: 100 cases in 3 years]

OBJECTIVE

To find the effectiveness of diagnoses of acute precordial pain seen as an emergency at our centre.

DESIGN

Observational, descriptive and retrospective study.

SETTING

Urban primary care centre.

PATIENTS

The 100 most recent patients who attended as an emergency with their first episode of acute precordial pain were included.

STUDY PERIOD

December 1994 to March 1998. Home visits, patients without medical records and those seen on repeated attendance for precordialgia were excluded.

MEASUREMENTS AND MAIN RESULTS

The emergency diagnosis and the diagnosis recorded afterwards in the clinical history of 100 people with acute precordialgia, aged 54.9 (16.7 years; 56% [n = 56] women), were gathered. Ischaemic cardiopathy (41%, n = 41) and mechanical precordialgia (36%, n = 36) were the most common initial diagnoses. We found 66.6% sensitivity and 81.4% specificity in the detection of ischaemic cardiopathy. The proportion of diagnostic errors was not linked to the pathological history of anxiety, ischaemic cardiopathy or oesophageal disease.

CONCLUSIONS

41% of precordialgias are diagnosed as presumably ischaemic and are potentially serious, although only 50% of them are confirmed as such. Our sensitivity in their diagnosis is comparable to that of other studies.

An economic analysis of an aggressive diagnostic strategy with single photon emission computed tomography myocardial perfusion imaging and early exercise stress testing in emergency department patients who present with chest pain but nondiagnostic electrocardiograms: results from a randomized trial

STUDY OBJECTIVE

Conventional emergency department testing strategies for patients with chest pain often do not provide unequivocal diagnosis of acute coronary syndromes. This study was conducted to determine whether the routine use of single photon emission computed tomography (SPECT) imaging at rest and early exercise stress testing to assess intermediate-risk patients with chest pain and no ECG evidence of acute ischemia will lead to earlier discharges, more discriminate use of coronary angiography, and an overall reduction in average costs of care with no adverse clinical outcomes.

METHODS

All patients in this study had technetium 99m tetrofosmin SPECT imaging at rest and were randomly assigned to either a conventional (results of the imaging test blinded to the physician) or perfusion imaging-guided (results of the imaging test unblinded to the physician) strategy. Patients in the conventional arm were treated at their physician's discretion. Patients in the perfusion imaging-guided arm were treated according to a predefined protocol based on SPECT imaging test results: coronary angiography after a positive scan result and exercise treadmill testing after a negative scan result. Study endpoints consisted of total in-hospital costs and length of stay. Hospital costs were calculated using hospital department-specific Medicare cost/charge ratios. Length of stay was calculated as total hospital room days billed (regular and intensive care).

RESULTS

We enrolled 46 patients, 9 with acute myocardial infarctions. Patients randomly assigned to the perfusion imaging-guided arm had $1,843 (95% confidence interval [CI] $431 to $6,171) lower median in-hospital costs and 2.0-day (95% CI 1.0 to 3.0 days) shorter median lengths of stay but similar rates of in-hospital and 30-day follow up events as patients in the conventional arm.

CONCLUSION

An ED chest pain diagnostic strategy incorporating acute resting (99m)Tc tetrofosmin SPECT imaging and early exercise stress testing may lead to reduced in-hospital costs and decreased length of stay for patients with acute chest pain and nondiagnostic ECGs.

Chest pain emergency centers: improving acute myocardial infarction care

Uncertainty and delay are common in the diagnosis of acute coronary syndromes (ACS). In the last 20 years, the need for faster, more accurate, and more cost-effective diagnosis gave rise to the concept of specialized treatment of patients with chest pain in emergency departments (EDs). The original strategy dedicated a separate section of the ED and a nursing staff to the task of rapid intervention in patients with acute myocardial infarction (MI) and triage of low-risk patients. Chest pain centers grew quickly in popularity but evolved with a variety of goals, staffing plans, diagnostic resources, and levels of commitment. There existing centers--the University of Cincinnati Heart ER, Brigham and Women's Hospital, and the Medical College of Virginia--have implemented chest pain strategies with the common aims of (1) screening for the entire spectrum of coronary artery disease, (2) avoiding unnecessary admissions, and (3) using multiple diagnostic modalities. Yet, they differ in the specifics of their approaches and diagnostic methods (e.g., echocardiography vs. treadmill vs. myocardial perfusion imaging). The safety and cost effectiveness of these centers are discussed.

Atypical chest pain

The initial approach to patients with a chief complaint of chest pain is to rule out myocardial ischemia. There are, however, other life-threatening causes of chest pain, including pulmonary emobilism and aortic dissection among many others. This article reviews several of these disease processes.