ACUTE CORONARY SYNDROMES

Acute coronary syndromes are not uncommon in the neuro-intensive care unit (NICU). These syndromes include unstable angina, non-ST segment elevation myocardial infarction (NSTEMI), and ST segment elevation myocardial infarction (STEMI). The mechanism underlying the acute ischemic episode remains the key to effective therapy.

Ischemia can be the result of plaque rupture, which requires therapies directed at reperfusion. Ischemia can also result from the increased myocardial demand in the setting of fixed stable coronary disease. Hypertension, sepsis, blood loss, and pain can each increase myocardial workload precipitating ischemia in the setting of stable coronary disease.

Traditional guideline directed management strategies of cardiac ischemia in a NICU setting require a risk benefit analysis due to comorbid conditions. Patients with recent head trauma, stroke, or operative procedures may require conservative treatment due to neurologic priorities. Efforts to treat plaque rupture through reperfusion techniques can cause significant morbidity in the NICU. Efforts to decrease myocardial workload usually cause less morbidity but blood pressure or heart rate lowering strategies can be challenging in the NICU.

Unstable Angina and NSTEMI

Unstable angina and NSTEMI are usually caused by atherosclerotic coronary disease. Disruption of atherosclerotic plaque leads to formation of thrombus and partial or transient occlusion of an epicardial coronary vessel. Chest pain as a result of unstable angina or NSTEMI is due to an imbalance between myocardial oxygen supply and demand. The vast majority of cases are due to inadequate supply due to coronary atherosclerosis.