Management: Once ACS is identified in the pregnant patient, initiate usual ED protocols [STEMI alert if indicated] plus contact OB team for rapid fetal monitoring of a viable fetus and OB planning. However, the mother should be treated first, before delivery, due to the high mortality risk of delivery in untreated ACS.

Hypotension: If over 24 weeks gestation put patient in left lateral decubitus position to either treat or prevent hypotension from caval compression. Administer nitroglycerin and morphine sulfate as in non-pregnancy. As in non-pregnant patients, nitroglycerin is contraindicated if systolic blood pressure is below 90 mmHg or greater than or equal to 30 mmHg below baseline, severe bradycardia (< 50 beats per minute), tachycardia ( > 100 beats per minute) in the absence of symptomatic heart failure, or right ventricular infarction. If patient is hypotensive despite position change and discontinuation of nitroglycerin, give fluids and pressors as indicated.

Hypertensive emergency: If patient experiencing hypertensive crisis with ACS, consider preeclampsia. Initiate treatment as in non-pregnancy with nitro, morphine. Consider adding labetalol drip as needed. If possible, avoid lowering blood pressure below 140/90 mm Hg because of potential for uterine hypoperfusion.

Medical Management: Medications generally used for ACS patients have a positive risk benefit profile in pregnancy. Some pregnancy related issues:

• Morphine: Communicate doses and times to delivery team so the effect on the fetus can be anticipated if delivered while medications are in the system.
• Nitrates: avoid maternal hypotension resulting in placental hypoperfusion. Tocolytic effect may slow labor.
• ASA: no significant issues.
• Heparin (unfractionated and low molecular weight), and clopidogrel: bleeding risks related to delivery, spinal anesthesia.
• beta-blockers: potential transient neonatal bradycardia, hypoglycemia, hypotension. Communicate dosing information to delivery team.
• Amiodarone: May lead to transient neonatal hypothyroidism, usually not associated with goiter. It is unrelated to either the dose or duration of amiodarone treatment. Exposure to amiodarone may also be associated with neurodevelopmental abnormalities, even in the absence of thyroid disease, but completely normal development has also been reported. Notify delivery team, even after relatively short treatment duration, so that evaluation for and treatment of neonatal hypothyroidism can begin in a timely manner.
• Oxytocin: If OB initiates oxytocin,be aware that it may induce chest pain, transient profound tachycardia, hypotension, and concomitant signs of myocardial ischemia with marked ECG changes. The effects are related to oxytocin; however, the patient needs to be watched carefully for possible AMI.

Post-acute phase testing: Patient should be evaluated further with minimally/non-invasive testing, such as echo and stress testing.