Missing ECG and Missed Diagnosis Lead to Dangerous Delay
A 35-year-old woman with no prior cardiac history called 911 after developing severe chest pressure at home. Based on the availability of local resources, a Basic Life Support Unit was dispatched. When emergency medical services (EMS) arrived at the patient's home, EMS providers obtained a 12-lead electrocardiogram (ECG) and administered aspirin. The ECG tracing showed ST elevations consistent with a large anterior wall myocardial infarction, or ST-elevation myocardial infarction (STEMI). According to protocol, EMS providers were required to transmit the ECG to the emergency department (ED) to activate "Code STEMI" while en route so that the cardiac catheterization laboratory, as well as necessary cardiology providers and staff, would be ready to treat the patient upon arrival to the hospital. Unfortunately, the ECG was not successfully transmitted to the ED (for technical reasons), which meant that the STEMI team was not activated in advance of the patient's arrival.
When the patient arrived in the ED, the clinicians (unaware of the original ECG) obtained a new ECG, which did not demonstrate the previously noted ST segment elevations. The patient's chest pain also seemed to be improving. She was treated with opioids for mild ongoing pain, and no additional ECGs or laboratory tests were ordered. She was subsequently admitted to the inpatient telemetry floor for overnight monitoring. The next morning, the patient's laboratory test results were notable for an elevated troponin level, suggesting that significant myocardial damage had occurred. Repeat ECG showed findings consistent with a large heart attack the prior day. She was rushed to the cardiac catheterization laboratory for emergency percutaneous coronary intervention (PCI). Because PCI had been delayed for many hours from the time of the original STEMI, the patient experienced significant loss of cardiac muscle function. She ultimately required placement of a device to assist her heart function and a prolonged stay in the cardiac intensive care unit.
by Robert E. O'Connor, MD, MPH
Virtually everything that could have gone wrong with this case did go wrong. The responsibility to provide emergency care to patients with acute coronary syndrome begins when the 911 call is received and should proceed seamlessly when the patient arrives in the emergency department (ED), where emergency medical services (EMS) personnel formally hand over the patient's care to the ED team. For patients with possible acute coronary syndrome, 911 call takers should assess the onset and duration of pain, along with pertinent medical history so that personnel capable of acquiring a 12-lead ECG are dispatched. Ideally, all EMS personnel who are trained to obtain an ECG tracing should also be trained to identify an ST-elevation myocardial infarction (STEMI) in case transmission of the ECG fails.(1)
In this case, EMS appropriately performed an ECG upon initial evaluation of the patient, but critical information was lost during transition of the patient's care to ED providers. Some EMS programs require that emergency medical technicians (EMTs) transmit the ECG tracing to a physician in the hospital before the cardiac catheterization lab at the receiving hospital can be activated. Transmission of the ECG may be hampered by technical problems, as happened in this case. Some EMS systems have overcome these barriers by using cell phones to transmit images of ECG tracings, or by training EMS providers to more immediately recognize a STEMI. Even if not transmitted ahead of a patient's arrival to the ED, the prehospital ECG may show clinically significant abnormalities that are not captured on the initial hospital ECG and may impact clinical management of the patient.(2)
In this case, EMS personnel transporting the patient recognized a STEMI on the ECG tracing and relayed their diagnosis to the hospital, but the staff member who answered the radio chose to disregard the information since the ECG tracing was not transmitted. Instead, the nurse answering the radio should have acted on the information provided by EMS personnel (even in the absence of the ECG) and activated the "Code STEMI" team prior to the patient's arrival in the ED. If seeing the tracing was necessary to activate a Code STEMI and to prepare the catheterization laboratory for the patient, the nurse could have asked EMS to take a picture of the tracing and transmit the image as an attachment to a text message, ideally through a secure application that would not raise concerns about violating patient privacy.
Many EMS systems have trained their EMS providers to recognize a STEMI as reliably as emergency medicine physicians are able to, thereby facilitating Code STEMI activation without the ECG transmission requirement. According to the integrated 2010 and 2015 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, EMS personnel should routinely acquire a 12-lead ECG as soon as possible for all patients exhibiting signs and symptoms of acute coronary syndrome. The ECG may be transmitted for remote interpretation by a physician or screened for STEMI by properly trained paramedics, with or without the assistance of computer interpretation.(3)
In this case, the nurse should have consulted with the emergency medicine physician to make a joint decision on whether or not to call a Code STEMI without having the ECG tracing available. The EMS- or emergency physician–activated Code STEMI results in simultaneous activation and response of cardiac catheterization personnel as well as the on-call interventional cardiologist. Code STEMI is designed to achieve timely activation of the cardiac catheterization laboratory.(4) The ideal door-to-intervention time is less than 90 minutes. This means that personnel must respond, set up the laboratory, receive and prepare the patient, perform the catheterization, identify vessel blockages, and open the artery in under 90 minutes.(5)
In the case described above, a critical communication breakdown occurred during the transition of care from the EMTs transporting the patient to the ED and the ED care team. No formal handoff regarding the results of the initial ECG tracing and the failure of transmission of the initial tracing occurred. Had there been a proper handoff, the prehospital ECG would have been seen by ED providers at the time of the handoff, the EMS providers' interpretation of the ECG would have been known, and a Code STEMI would have been activated. Handoffs between EMS and ED personnel require information transfer, so that professional responsibility and accountability can be passed from prehospital care providers to hospital staff. The American College of Emergency Physicians policy regarding transfer of patient care between EMS providers and receiving facilities states (6): "In addition to a verbal report from EMS providers, the minimum key information required for patient care must be provided in written or electronic form at the time of transfer of patient care…. Copies of all results of medical tests performed by EMS providers (e.g., 12-lead ECGs, results of blood chemistry testing, and any medical imaging) must be available to the receiving facility with the EMS transfer-of-care documentation." What happened in this case represents a failed handoff of care.
Acute coronary syndrome is a dynamic process, as illustrated by changes in this patient's ECG tracing over time. It is not unusual for a baseline prehospital ECG to show ST segment elevations and for a repeat ECG to subsequently normalize upon hospital arrival. These changes likely represent a response to treatment provided by EMS, such as rest, oxygen, aspirin, and nitroglycerin. For this reason, serial ECG tracings are valuable in recognizing changes consistent with STEMI and in making the correct diagnosis. Those caring for the patient in this case had access to vital information that would have resulted in the patient undergoing immediate intervention in the cardiac catheterization laboratory to open the blocked coronary artery, but this information was somehow lost and the resulting delay in intervention led to permanent myocardial damage and loss of cardiac function.
Chest pain has a wide array of causes, ranging from ones that are benign and self-limited to others that are life threatening. Emergency medicine physicians are trained to exclude the "worst first" and to "rule in" a more benign cause only after excluding more serious ones. It is unusual for a 35-year-old woman to have a STEMI. Because the patient's pain had resolved and the ECG in the ED was normal, the ED provider may not have considered the diagnosis of acute coronary syndrome. The diagnosis would not have been missed had there been better communication between EMS personnel and the ED team on initial radio contact, between the nurse receiving the call and the ED physician, and between EMS and ED staff on patient arrival. In addition, if the ECG had been made available to ED staff, a Code STEMI would have likely been called before the patient arrived in the ED.
- Always obtain a prehospital ECG when treating patients with suspected acute coronary syndrome.
- Prehospital personnel should receive training to identify an ST-elevation myocardial infarction on a 12-lead ECG.
- Emergency department personnel should activate "Code STEMI" based on a transmitted ECG tracing, or on paramedic interpretation if the ECG tracing cannot be easily transmitted.
- Standardized handover of care should always occur between emergency medical services and emergency department personnel when patients arrive via emergency medical services in the emergency department.
Robert E. O'Connor, MD, MPH Professor and Chair Department of Emergency Medicine University of Virginia School of Medicine Charlottesville, VA
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