Cardiac Stress Testing
February 2005
Cardiac Stress Testing
“If I see another chest pain patient today, I might just drop out of residency”, you tell yourself as you scan the HMED board for the next patient during your already busy EM1 shift. You regrettably note that the next three patients waiting to be seen are all middle-aged individuals with chief complaints of “chest pain”. Having already admitted three chest pain patients to the Medicine service which is now full, you dread the impending hassle the variety of phone calls to any combination of primary care physicians (PCP), Cardiology consultants, triage residents, and overflow services that some or all of these four patients will entail.
Biting your lip and remembering that your first and most important job is as a patient advocate, you enter Mrs. X’s room and obtain the following history: 45 year old Caucasian female with no known past medical history who noted onset of left-sided chest pain twelve hours ago with radiation of pain to her left arm. Pain has a “burning” quality and is similar to previous bouts of “reflux”, but unrelieved with over-the-counter antacids. She specifically denies any cardiac risk factors, but has not seen a physician for over 10 years. On physical exam you note normal blood pressures, heart rate, and oxygen saturation with no abnormal heart sounds or evidence of right-sided failure and no reproducible chest pain. Her electrocardiogram (EKG) reveals poor R-wave progression across the precordial leads, but is otherwise unremarkable and no old EKG for comparison can be found. Initial labs, including a Troponin-I and myoglobin, are unremarkable, as is her chest x-ray.
She has complete relief of her chest pain in the ED after nitroglycerine, aspirin, and morphine are administered (with a heart rate of 60 and systolic blood pressure 120, beta-blockers were not administered). Although you feel that her risk of a coronary etiology of chest pain is remote, your attending feels uncomfortable with discharging someone home without a clear etiology of her chest pain syndrome who has not seen a physician for a decade. Because she has no PCP and our Observation Unit has no slots remaining for stress tests tomorrow, you contact the Triage resident to admit her for serial cardiac enzymes and a stress test prior to discharge home.
To your utter shock and amazement, the Triage resident believes that the admission is unnecessary and that outpatient stress testing would be appropriate. Furthermore, after reviewing your last chest pain admission, the Triage resident informs you that Mr. Y had had a stress test 18 months prior and that despite his multiple risk factors, his current chest pain “is highly unlikely to represent atherosclerotic coronary disease” and “you wasted a bed before”. With a little arm twisting, you nonetheless have Mrs. X admitted, but you are sick of having the ulcer developing each time you anticipate a conversation with the Triage resident regarding the appropriate disposition and work-up of chest pain patients, so you vow to review the literature before your next shift.
As the ED evaluation of chest pain represents an exceedingly common pathology, you begin your search by screening the pre-filtered database of EM Abstracts with the search terms “myocardial ischemia” and are immediately rewarded with the following articles:
Years
First years: Accuracy of imaging technologies in the diagnosis of acute cardiac ischemia in the Emergency Department: a meta-analysis. Annals EM 2001; 37: 471-477
Second years: Myocardial perfusion imaging for evaluation and triage of patients with suspected acute cardiac ischemia: a randomized controlled trial. JAMA 2002; 288: 2693-2700.
Third years: Value of definitive diagnostic testing in the evaluation of patients presenting to the Emergency Department with chest pain. Am J Cardiology 2003; 91: 1410-1414.
Fourth years: Impact of a clinical decision rule on hospital triage of patients with suspected acute cardiac ischemia in the Emergency Department. JAMA 2002; 288: 342-350.1.
Forms
First Year Residents: use the Meta-analysis Critical Review Form
Second Third Year Residents: use the Diagnostic Critical Review Form
Fourth Year Residents: use the Clinical Decision Rule Critical Review Form
Articles
Article 1: Accuracy of Imaging Technologies in the Diagnosis of Acute Cardiac Ischemia in the ED: A Meta-Analysis, Annals EM 2001; 37: 471-477.
ANSWER KEY
Article 2: Myocardial Perfusion Imaging for Evaluation and Triage of Patients with Suspected Acute Cardiac Ischemia: A Randomized Controlled Trial, JAMA 2002, 288: 2693-2700
ANSWER KEY
Article 3: Value of definitive diagnostic testing in the evaluation of patients presenting to the ED with chest pain, Am J Cardiology 2003; 91: 1410-1414.
ANSWER KEY
Article 4: Impact of a clinical decision rule on hospital triage of patients with suspected acute cardiac ischemia in the emergency department, JAMA 2002; 288: 342-350.
ANSWER KEY
Bottom Line
Does your review suggest that myocardial perfusion imaging is indicated for all patients presenting to the ED with a chief complaint of chest pain? If your answer is no, define the subset of patients upon whom “definitive diagnostic testing” should be performed and identify what you mean by “definitive diagnostic testing”.
How should we approach admitting consultants hesitant to search for a cardiac etiology of chest pain?
What important facts should you review specific to each patient and particularly each stress test before concluding that additional observation or inpatient testing is unnecessary?
How long after diagnostic, provocative, cardiac stress testing do you believe is “safe” to exclude the progression of significant, symptomatic coronary disease? 1-year? 3-years? 5-years? Forever?