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Unstable Angina

Unstable angina typically presents with a prolonged episode of substernal chest pain, or as stable angina that has been increasing in frequency, severity, or 

The diagnosis of unstable angina depends on clinical history, physical examination, and a 12-lead ECG. Compared with patients with stable angina, those with unstable angina are more likely to have multivessel disease and progression of known unstable angina, chest pain atherosclerosis. Pain may be accompanied by reversible, horizontal or 

Factors that May Precipitate Unstable Angina. Lung disease (chronic obstructive pulmonary unstable angina, chest pain disease).  Anemia (occult gastrointestinal bleeding) unstable angina, chest pain.  Fever or hyperthyroidism. Uncontrolled hypertension or arrhythmias unstable angina, chest pain Unstable Angina, Chest Pain Unstable Angina, Chest Pain

Initial Medical Treatment of Unstable Angina Unstable Angina, Chest Pain

Anti-ischemic therapy should be initiated as soon as the working diagnosis of unstable angina is made.

Supplemental oxygen, at 2-4 L/min by nasal canula, should be given to patients with cyanosis, respiratory distress, or high-risk features.

Obtain a brief history, physical examination, and ECG.

Initial Laboratory. CBC count, lipid profile and blood glucose levels; creatine kinase MB q3h over the next 12 hours, troponin T levels; chest x-ray.

Nitrates are indicated for ongoing anginal pain Unstable Angina, Chest Pain or ischemia. Nitrates decrease oxygen demand by reducing preload, and they dilate coronary arteries. Reflex tachycardia increases oxygen demand; therefore, heart rate must be controlled.

Nitroglycerine 15 mcg IV bolus, then 5-10 mcg/min infusion (50 mg in 250-500 mL D5W, 100-200 mcg/mL). Titrate every 3-5 minutes to control symptoms in 5-10 mcg/min steps, up to 200-300 mcg/min. Avoid tachycardia and Unstable Angina, Chest Pain hypotension.

Nitroglycerine Sublingual, 1-3 tabs SL prn chest pain may also be used. Aspirin should be given upon presentation, 160 mg chewed and swallowed immediately, then take 325 mg daily (range 160-325 mg daily).

Contraindications. Hypersensitivity, active bleeding. Peptic ulcer disease is not a contraindication in the setting of unstable angina.

Ticlopidine (Ticlid) has proved to be effective in unstable angina because it blocks fibrinogen binding to platelets. 250 mg bid is an alternative if aspirin is contraindicated or ineffective; may cause neutropenia, skin rash, diarrhea.

Beta-blockers reduce myocardial oxygen consumption and heart rate contractility. Monitor heart rate and blood pressure (target heart rate for beta-blockade is 50-60 beats per minute). Monitor for congestive heart Unstable Angina, Chest Pain failure and bronchospasm.

Contraindications: PR segment > 0.24 sec; 2 or 3 AV block; heart rate <60; systolic BP <90 mm Hg; CHF, severe reactive airway disease.

Metoprolol (Lopressor), cardioselective beta1-blocker; 1-5 mg doses by slow IV infusion over 1-2 min. q5min to 15 mg total; 100 mg Unstable Angina, Chest Pain PO bid; reduces the risk of recurrent ischemia or myocardial infarction within 48 hours.

Atenolol (Tenormin), cardioselective beta1-blocker; 5 mg IV q5min to 10 mg total; 50-100 mg PO qd.

Esmolol (Brevibloc)

Cardioselective beta1-blocker; it has the advantage of a short half-life of 9.5 minutes. 2 mg/min IV infusion, increase up to 24 mg/min. Unstable Angina, Chest Pain The dose is increased at 5-minute intervals to achieve a 25% reduction in heart rate. May be immediately withdrawn if bradycardia, heart block, hypotension, bronchospasm, or heart failure occur.

Heparin in unstable angina reduces the risk of MI and recurrent unstable angina in high-risk patients if begun early. Patients with unstable angina and hypotension, pulmonary edema, significant prolonged rest pain, or other high-risk features, without contraindications, should receive aspirin and heparin, while those with lower-risk unstable angina should receive aspirin alone. 80 U/kg IV bolus, then IV infusion at 18 U/kg/h titrated to a activated partial thromboplastin time (aPTT) 1.5-2.5 times control. Check the aPTT q6h until a therapeutic level has been achieved on two consecutive aPTT's. Obtain an aPPT every 24 hours thereafter. Obtain hemoglobin/hematocrit and platelets daily for the first 3 days of heparin, or if bleeding, recurrent ischemia, or hypotension. Monitor for heparin-induced thrombocytopenia.

Thrombolytic therapy is not indicated if there is no evidence of acute ST-segment elevation or left bundle branch block on 12-lead ECG. Thrombolytic agents do not have a beneficial effect in unstable angina.