(Whether or not reperfusion therapy is undertaken):

• Hospitalize in CCU with continuous ECG monitoring.
• IV line for emergency arrhythmia treatment.
• Pain control: (1) Morphine sulfate 2-4 mg IV q5-10 min until pain is relieved or side effects develop (nausea, vomiting, respiratory depression [treat with naloxone 0.4-1.2 mg IV], hypotension [if bradycardic, treat with atropine 0.5 mg IV; otherwise use careful volume infusion]); (2) nitroglycerin 0.3 mg SL if systolic bp >100 mmHg; for refractory pain: IV nitroglycerin (begin at 10 µg/min, titrate upward to maximum of 200 µg/min, monitoring bp closely); do not administer nitrates within 24 h of sildenafil or within 48 h of tadalafil (used for erectile dysfunction); (3) β-adrenergic antagonists (see below).
• Oxygen: 2-4 L/min by nasal cannula (if needed to maintain O₂ saturation >90%).
• Mild sedation (e.g., diazepam 5 mg, oxazepam 15-30 mg, or lorazepam 0.5-2 mg PO three to four times daily).
• Soft diet and stool softeners (e.g., docusate sodium 100-200 mg/d).
• β-Adrenergic blockers (Chap. 117. Hypertension) reduce myocardial O₂ consumption, limit infarct size, and reduce mortality. Especially useful in pts with hypertension, tachycardia, or persistent ischemic pain; contraindications include active CHF, systolic bp <95 mmHg, heart rate <50 beats/min, AV block, or history of bronchospasm. Consider IV (e.g., metoprolol 5 mg q2-5min to total dose of 15 mg) if pt is hypertensive. Otherwise, begin PO regimen (e.g., metoprolol tartrate 25-50 mg four times daily).
• Anticoagulants: Most pts with STEMI should receive an anticoagulant (typically unfractionated heparin [UFH] or bivalirudin for those undergoing PCI [discontinued at end of procedure or shortly thereafter]; enoxaparin [for up to 8 days, or until discharge, whichever is earlier] or UFH [for ≥2 days] for those receiving fibrinolysis or no reperfusion therapy). Continued full-dose IV heparin (PTT 1.5-2 × control) or LMWH (e.g., enoxaparin 1 mg/kg SC q12h) followed by warfarin is recommended for pts with high risk of thromboembolism (severe LV dysfunction, presence of ventricular thrombus, large dyskinetic region in acute anterior MI, or pulmonary embolism). If used, warfarin is continued for 3-6 months.
• Antiplatelet agents: Continue aspirin 162-325 md daily and an oral P2Y₁₂ platelet receptor antagonist after STEMI (e.g., ticagrelor, clopidogrel, or prasugrel [the latter only if PCI is undertaken]).
• ACE inhibitors reduce mortality in pts following acute MI and should be prescribed within 24 h of hospitalization for pts with STEMI—e.g., captopril (6.25 mg PO test dose advanced to 50 mg PO tid). ACE inhibitors should be continued indefinitely after discharge in pts with heart failure or those with asymptomatic LV dysfunction (ejection fraction ≤40%); if pt is ACE inhibitor intolerant, use ARB (e.g., valsartan or candesartan).
• Aldosterone antagonists (spironolactone or eplerenone 25-50 mg daily) further reduce mortality in pts with LVEF ≤40% and either symptomatic heart failure or diabetes; do not use in pts with advanced renal insufficiency (e.g., creatinine ≥2.5 mg/dL) or hyperkalemia.
• Serum magnesium level should be measured and repleted if necessary to reduce risk of arrhythmias.