A 70-year-old man with a history of coronary artery disease presents to the emergency department with 2 hours of substernal chest pressure, diaphoresis, and nausea. He reports difficulty "catching his breath." An electrocardiogram shows septal T-wave inversion. The patient is given 325 mg aspirin and sublingual nitroglycerin while awaiting the results of his blood work. His troponin I is 0.65 ng/mL (normal <0.04 ng/mL). The physician in the emergency department starts the patient on low-molecular-weight heparin. His pain is 3/10. Blood pressure is currently 154/78 and heart rate is 72. You are asked to assume care of this patient. What is the best next step in management?
The patient's history suggests acute coronary syndrome (ACS). The combination of elevated troponin and lack of ST segment elevation on ECG is most consistent with non-ST elevation myocardial infarction (NSTEMI). Initial therapy for acute coronary syndrome includes aspirin, nitroglycerin, anticoagulation, and morphine. An intravenous beta-blocker, such as metoprolol, is frequently given in the immediate management of ACS to decrease myocardial oxygen demand, limit infarct size, reduce pain, and decrease the risk of ventricular arrhythmias. Elevated blood pressure also increases myocardial oxygen demand. Given this patient's increased blood pressure and continued pain, administration of a beta-blocker is the appropriate next step in his management. Administration of intravenous morphine would also be appropriate.Cardiac catheterization may well be necessary at some point during his evaluation, but there is no mortality benefit for emergent catheterization in NSTEMI. There is no role for thrombolytic therapy in patients with ACS without ST segment elevation. All patients with ACS should be admitted to a monitored cardiac unit with serial cardiac biomarkers to estimate the extent of cardiac damage, but the patient's continued pain demands urgent treatment, not just further observation. Clopidogrel therapy is indicated for patients with ACS who will not be undergoing immediate coronary artery bypass grafting (CABG). Clopidogrel therapy, however, will not improve this patient's elevated blood pressure nor promptly decrease myocardial oxygen demand. The correct dose of clopidogrel is a loading dose of 300 to 600 mg, then 75 mg po daily.
Arrange for emergent cardiac catheterization
Begin intravenous thrombolytic therapy
Admit the patient to a monitored cardiac bed and repeat cardiac enzymes and ECG in 6 hours
Begin intravenous beta-blocker therapy
C.V.S.