The treatment of a patient with myocardial infarction is thrombolytic therapy, if the patient presents within hours of chest pain -
Ref: R Alagappan - Manual of Practical Medicine 4th Edition.pg no:188 Thrombolytic therapy (Streptokinase, Urokinase, Tissue plasminogen activator) may be given and is paicularly useful if given within 6 hrs of onset of Comparison of Anterior and Inferior Wall Myocardial Infarction Features Anterior MI Inferior MI 1. Extent of necrosis Large Small 2. Extent of coronary atherosclerosis Small Large 3. Complications a. Ventricular septal rupture Apical, easily repaired Basal, difficult to repair b. Aneurysm Common Uncommon c. Free wall rupture Uncommon Rare d. Mural thrombus Common Uncommon e. Hea blocks Uncommon Common f. Bundle branch blocks Common Uncommon 4. Prognosis Worse than that of inferior MI Better than that of anterior MI 5. Diagnosis a. Symptoms Gastrointestinal symptoms unusual Gastrointestinal symptoms (nausea, vomiting, hiccough) common b. Physical examination Tachycardia; hypotension uncommon. Bradycardia; hypotension common. Jugular venous distention less Jugular venous distention common. common than with inferior MI. 20% have S3 50% have S3 c. ECG Features of anterior wall MI Features of inferior wall MI d. Echocardiogram Abnormal left ventricular wall Abnormal left ventricular wall motion motion is anterior in location. is inferior in location. Right ventricular No abnormal right ventricular abnormal wall motion present in wall motion approximately one-third of patients. symptoms, but may be given upto 12 hrs after onset of symptoms. Ideal--door to needle time 30 min. Thrombolytic agents for Myocardial Infarction Agents with fibrin specificity: 1. Alteplase (-PA) 15 mg IV bolus followed by 0.75 mg/kg IV infusion (upto 50 mg) over 30 minutes then 0.5 mg/kg (upto 35 mg) by IV infusion over 60 minutes (maximum dose 100 mg IV over 90 minutes) 2. Reteplase (r-PA) 10 mg IV bolus over 2 minutes followed by another 10 mg IV bolus after 30 minutes. 3. Tenecteplase (TNK-tPA) 0.5 mg/kg IV bolus (<60 kg-30 mg, 61-70 kg -35 mg, 71-80 kg-40 mg, 81-90 kg- 45 mg, >90 kg-50 mg) Agents without fibrin specificity: 1. Streptokinase - 1.5 million units IV infusion over 60 minutes 2. Urokinase Because of the development of antibodies, patients who were previously treated with streptokinase should be given an alternate thrombolytic agent.
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