You are on a swing shift at a remote, island-based community hospital when a 58 year-old male presents with sudden onset chest pain. The pain started at rest, radiates to his jaw, and is associated with diaphoresis and nausea. He has a history of coronary artery disease (CAD), and during his last cardiac catheterization in 2008, a stent was placed in his proximal left anterior descending coronary artery. His past medical history is also significant for diabetes, chronic obstructive pulmonary disease, hyperlipidemia, and hypertension. He is an active smoker.
On exam, he is not only diaphoretic and clenching his chest, but also describes the pain as “an elephant sitting on my chest.” Initial vital signs are P 110, BP 175/100, RR 20, PO2 98% on RA, T 98.9 F. You give him aspirin 324 mg and nitroglycerin sublingual 0.4 mg, and his chest pain improves from a 10/10 to 8/10. His initial electrocardiogram (EKG) is below.
ST elevation myocardial infarction (STEMI)
You call the critical care transport ambulance, as well as the nearest cardiac catheterization team to alert them of your patient. Unfortunately, it is a stormy evening in the middle of winter and all bridges off the island are closed; helicopters are grounded due to the storm. There are no transfer options available to your patient at this time. What else can you do?
Indications for Fibrinolytic Therapy
According to the American Heart Association, there are several considerations when it comes to fibrinolytic therapy in myocardial infarction:
Class I recommendations:
Symptom onset in the last 12 hours
Percutaneous Cardiac Intervention (PCI) cannot be performed within 120 minutes of arrival to the Emergency Department
Absence of any contraindications (see below)
Class II recommendations:
Evidence of ongoing ischemia 12-24 hours after symptom onset
Large area of myocardium affected
Any prior intracranial hemorrhage
Known structural cerebral vascular lesion
Ischemic stroke <3 months
Suspected aortic dissection
Known intracranial malignancy
Active bleeding or bleeding diathesis
Significant closed head trauma <3 months
Intracranial/intraspinal surgery <2 months
Severe uncontrolled HTN (>175/110)
Significant HTN on arrival (pressure > 180 mmHg)
Ischemic stroke >3 months
Other intracranial pathology
Traumatic CPR >10 min
Major surgery <3 weeks
Internal bleeding <3 weeks
Non-compressible vascular punctures
Active peptic ulcer disease
PCI versus Systemic Fibrinolytic Therapy
If you are able to transfer the patient to a hospital with PCI capability within 1 hour of presentation or they have contraindications to fibrinolytic therapy, it is recommended that you transfer the patient as soon as possible. Otherwise, the goal is fibrinolytic infusion within 30 minutes of arrival to the ER. In either case, concurrently initiate maximal medical management including full-dose aspirin, Plavix or Brilinta, and anticoagulation (unfractionated heparin or lovenox). Tenecteplase is generally the preferred fibrin-specific agent, given its ease of use and lower rates of non-cerebral bleeding compared to other agents.
Reassess After Fibrinolysis
If your patient has resolution of chest pain and >70% reduction of ST elevation, or ST elevation resolves within 60-90 minutes, you have likely restored flow. If you see <50% decrease in STE and no reperfusion arrhythmias (see below) at 2 hours after fibrinolytic dosing, you have partially improved flow but not completely restored it.
Criteria for Transfer after fibrinolytic therapy
Immediate transfer: acute heart failure or cardiogenic shock
Urgent transfer: failed reperfusion or reocclusion
3-24 hours: hemodynamically stable, successful reperfusion
You plan for ICU admission because you are unable to transfer the patient to a PCI center when the nurse hands you the following EKG:
This is an example of accelerated idioventricular rhythm. This is a normal sign of reperfusion after STEMI and does not require treatment. In fact, such a rhythm is generally viewed as a positive response to fibrinolytic therapy as indicates reperfusion.
Rate 50-110bpm (slower is ventricular escape, faster is VT)
Three or more ventricular complexes
Fusion (F) and capture (C) beats (see below)
General goals of care after fibrinolytic therapy should be to transfer for diagnostic angiography and percutaneous coronary evaluation which is promptly accomplished for your patient the following day after the storm resolves.
Faculty reviewer: Dr. Kristina McAteer
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