■ Safety of care:

Improving patient safety and reducing risks

The diagnostic challenges of chest pain: Recognizing acute coronary syndrome

6 minutes

Published: December 2019

The information in this article was correct at the time of publishing

Diagnosing a patient presenting with chest discomfort or pain remains a challenge for physicians despite advances in diagnostic testing, clinical practice guidelines, and enhanced understanding of acute coronary syndrome (ACS). Appropriate triage and testing, as guided by symptoms and patient risk factors, may help improve the timely diagnosis of ACS.

Case example: Failure to recognize potential significance of chest pain symptoms results in lack of timely referral to emergency department

A man in his 50s visits his family physician on a Monday morning. He complains of intermittent left-sided chest pain that he felt since his return from a party on Saturday night. He has a history of smoking, but no other cardiac risk factors. The physician suspects gastroesophageal reflux from excessive consumption of alcohol, and his differential diagnosis includes pancreatitis, cardiac chest pain, and influenza. The physician orders a chest X-ray, ECG, bloodwork, and an abdominal ultrasound. A few hours later, the patient has an ECG performed at a local laboratory where a computerized interpretation suggests an anterior infarction. No immediate action follows at the laboratory. The patient dies the following morning, less than 24 hours after the ECG. A cardiologist receives the ECG five days later, and interprets the findings as an acute anterior myocardial infarction.

In their complaint to the College, the patient’s family cites the physician’s lack of urgency in ordering and following up on the tests, and questions the laboratory’s procedures, which allowed the patient to leave without being informed of his condition. Though supportive of the family physician’s assessment and differential diagnosis, the College agrees that he ought to have arranged testing with an appropriate level of urgency. The College is critical that the patient was not referred to the emergency department, where troponin and ECG testing could have been more promptly carried out. After gathering evidence of the physician’s self-directed education and improvements to the system of diagnostic testing, the College dismisses the case with concern.

CMPA cases of acute coronary syndrome

An analysis by the CMPA of legal actions, regulatory authority (College), and hospital complaint cases closed between 2014 and 2018 identified 197 files featuring ACS. Of these, 116 involved allegations or findings of diagnostic error (missed, delayed, or inaccurate diagnoses), with the majority (72/116) occurring in the assessment and testing phases of the diagnostic process. Emergency department settings predominated (79/116), followed by primary care settings (30/116), with surgical cases, care by internists, and cardiology consultations making up the balance. In cases of diagnostic error, peer experts,1 Colleges, and hospitals frequently focused their criticisms on two areas: inadequate serial testing (ECG and cardiac enzymes) in emergency care settings, and delay in referral to the emergency department in primary care settings.

Consideration of patient risk factors and diagnostic testing decisions in emergency and primary care

Two main themes arose in cases related to deficient assessment: consideration of patient risk factors (24/72) and diagnostic testing decisions (35/72), though the particulars varied by practice setting. Regarding the assessment of patient risk factors for coronary artery disease, criticism of primary care practitioners often focused on a failure to recognize pain or discomfort with possible cardiac origins, thus delaying urgent referral to the emergency department. In contrast, for emergency care, criticisms centered on the failure to consider cardiac risk factors in the diagnosis of unexplained chest discomfort or pain. With respect to diagnostic testing, care in the emergency department was subject to criticism for insufficient serial ECG and enzyme testing, while care provided in office settings was subject to criticisms around a lack of urgency in referring patients for such testing.

Diagnosing ACS in female patients

Another theme identified among the CMPA cases reviewed was the diagnostic challenge of chest pain among female patients. Consistent with larger epidemiological studies of ACS, females comprised approximately 28% of the sample (33/116) and experienced severe clinical outcomes, with 17 of 33 cases resulting in the patient’s death. Consistent with the medical literature,2,3 risk factors for women also displayed gender-specific characteristics, such as menopause and pregnancy, and women frequently presented with atypical chest pain.


Case example: Misinterpretation of clinical signs leads to inappropriate risk stratification

A woman in her early 30s presents to an emergency department in a rural hospital, complaining of severe chest pain radiating to her left arm and a burning sensation in her lungs. She is anxious, tearful, and hyperventilating.

Nursing staff perform an ECG and measure vital signs, which are normal apart from borderline high blood pressure. The patient reports a history of depression, smoking, and the use of medroxyprogesterone. Other details of her medical history missed during the assessment include a family history of cardiac disease, a previous transient ischemic attack, and high cholesterol levels. Hospital policies include a medical directive allowing nurses to expedite troponin testing for patients over 40 who present with chest pain, but they do not apply it owing to the patient’s age. The physician reviews the ECG and arranges a chest X-ray, both of which are judged to be normal. On physical examination, he notes chest wall tenderness, which the patient attributes to recent heavy lifting. The physician’s differential diagnosis includes the possibility of cardiomyopathy, but he believes that the patient’s young age and the ECG rule this out.

After analgesia, the patient’s pain decreases and she appears comfortable. The physician discharges the patient from the emergency department with a diagnosis of musculoskeletal pain and instructions to return if she experiences further symptoms. Following a cardiac arrest at home several hours later, the patient returns to the emergency department by ambulance. She dies from cardiogenic shock due to myocardial infarction.

The patient’s family complains to the College and pursues a legal action, alleging that the physician inappropriately discharged the woman from hospital without a clear diagnosis. Peer experts support the physician’s care, and the legal case is dismissed.

The College, however, is critical of the physician’s documentation and a differential diagnosis that narrowed too quickly. The College also finds it inappropriate that the physician relied on the medical directive to guide his diagnostic testing decisions, and suggests that the physician’s clinical judgment should have dictated whether to perform a troponin test. The College takes no action on the condition that the physician completes an educational course on documenting ACS risk factors and assessing patients with atypical chest pain.


What is risk stratification?

Risk stratification is an ongoing process where a health provider uses clinical diagnostic indicators to proactively classify patients into high-, medium-, and low-risk categories. The goal of risk stratification is to effectively target healthcare services for individual patients and guide the management of patient care.

Risk reduction strategies

Based on the expert opinions in the cases reviewed, the following risk reduction strategies may be suitable in your practice:

  • Consider applicable clinical guidelines,4,5 including those recommending key serial diagnostic tests when considering the differential diagnosis of ACS in an emergency setting. When guidelines are not followed, document the reasons why.
  • Consider employing a risk stratification strategy to help guide decisions concerning diagnostic testing in the emergency department.
  • Consider cardiac risk factors to aid with the triage of patients presenting with symptoms of non-specific chest discomfort or pain in a primary care setting.

The bottom line

Recognizing ACS is a relatively common and challenging task. An awareness of patient risk factors to aid triage in primary care, or clinical risk stratification and appropriate serial testing in the emergency department, can contribute to safer patient care and reduced medical-legal risk.

Additional reading


  1. Peer experts refer to physicians retained by the parties in a legal action to interpret and provide their opinion on clinical, scientific, or technical issues pertaining to the care provided. They are typically of similar training and experience as the physicians whose care they are reviewing.
  2. Mehta LS, Beckie TM, DeVon HA, et al. Acute myocardial infarction in women: a scientific statement from the American Heart Association. Circulation. 2016;133:916-947
  3. Pagidipati NJ & Peterson ED. Acute coronary syndromes in men and women. Nat Rev Cardiol. 2016 Aug; 13(8):471-80
  4. Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes. Circulation. 2014;130:e344-e426
  5. Mancini GB, Gosselin G, Chow B, et al. Canadian Cardiovascular Society guidelines for the diagnosis and management of stable ischemic heart disease. Can J Cardiol. 2014; 30(8): 837-849

DISCLAIMER: The information contained in this learning material is for general educational purposes only and is not intended to provide specific professional medical or legal advice, nor to constitute a "standard of care" for Canadian healthcare professionals. The use of CMPA learning resources is subject to the foregoing as well as the CMPA's Terms of Use.