A 48-year-old man has a prior history of hypertension, dyslipidemia, diabetes mellitus and 2 weeks previously had a L3-L4 laminectomy and spinal fusion for severe radiculopathy. On postopeartive day 15, he suddenly develops chest pain, waking him from sleep in the early morning. It is a squeezing, pressure-like sensation in the midline of his chest, without radiation. He has moderate dyspnea and palpitations, which began at the same time as his chest pain. Symptoms do not abate after a few hours, and the patient presents to the emergency department. On further questioning, he admits that he had felt several episodes of mild chest discomfort for the last several months while doing yard work, but it was always mild and transient. He did not report it to his primary doctor at his preoperative evaluation. Symptoms have been minimal recently, but his physical activity has been markedly reduced because of back pain. His blood pressure is controlled on amlodipine. He takes low-dose simvastatin for high cholesterol, and his diabetes is diet controlled. His only other medication is ibuprofen as needed for chronic back pain. He is a former heavy smoker but successfully quit 1 month before his laminectomy. He does not drink or use illicit drugs. Family history is notable for his father’s demise at age 65 of a stroke. He is still having mild-to-moderate chest discomfort on arrival in the emergency department. His vital signs are temperature 37°C; heart rate, 105; blood pressure, 155/90; respiratory rate, 20; and oxygen saturation, 98% on 2 L nasal cannula. He appears anxious and uncomfortable but is not in distress. ECG shows normal sinus rhythm with downsloping ST segment depressions in the inferior and lateral leads (Figure 35-1). His preoperative ECG is normal, and a chest radiograph is clear.
ECG of a 48-year-old man who presents to the emergency department with chest pain. Note the ST-segment depressions in the lateral and inferior leads.
What are the different presentations of an acute coronary syndrome (ACS)?
ACS is a term that encompasses several conditions: unstable angina (UA), non-ST segment elevation myocardial infarction (NSTEMI); ST segment elevation myocardial infarction (STEMI); and sudden cardiac death due to myocardial infarction. Cardiac chest pain, or angina, is the typical symptom. In ACS, the chest pain is usually new or progressing compared with prior chest pain. It may increase in frequency, severity, or duration, or occur at rest. Angina that is predictable, exertional, and resolves with rest or nitroglycerin is referred to as stable angina. Stable angina is not ACS. The above patient appears to have a history of stable angina, but is now presenting with unstable angina.
Many individuals will experience ACS without significant chest discomfort. This is especially common among elderly persons, women, and those with diabetes mellitus, all of whom ...