FACTORS INFLUENCING THE OUTCOME OF THROMBOLYSIS IN ACUTE MYOCARDIAL INFARCTION

Abstract

Introduction: Coronary heart disease has been dened as "impairment of heart function due to inadequate blood ow to the heart compared to its needs, caused by obstructive changes in the coronary circulation to the heart." It is the cause of 25-30% of death in most of the industrialized countries. In India also, it is a major public health problem. It is aptly called by WHO as the modern epidemic. The increasing incidence of coronary heart disease may be a reection of increased longevity, adoption of high-fat diet based on meats, decreased exercise, modern lifestyle, made possible by increasing afuence. The primary goal of thrombolytic therapy is rapid, complete and sustained restoration of infarct related artery blood ow. Success rate of thrombolysis and thus the overall reduction in mortality is different among different agents used. To nd out the overall success rate of thrombolysis in intensive care unit. Find outAIMS & Objective: whether the following parameters inuence the outcome of thrombolysis and determine their role in the success/ failure of thrombolysis. Material and Methods: Patients were included who is, presence of typical chest pain suggestive of Acute myocardial infarction along with ECG evidence Criteria for thrombolysis being 2 mm or more ST elevation in two contiguous precordial leads or 1 mm or more ST elevation in two contiguous limb leads. Time window of 12 hrs. from the onset of pain to the initiation of thrombolysis. All patients received streptokinase 1.5 million units in 100ml of normal, saline over 60Drug Therapy : minutes, Aspirin was given to all patients, Use of heparin, -blockers, ACE Inhibitors was according to ICU protocols, which was in accordance with ACC/AHA recommendations. Success was dened by: Clinical-Denition of success of thrombolysis: complete subsidence of chest pain, Electrocardiographically-more than 50% ST resolution in a lead which showed maximum ST elevation initially. ST elevation is measured manually, 80ms after J point from isoelectric line. Preceding PR segment is taken as isoelectric line. Patients were analyzed for success of thrombolytic therapy at 90 minutes after initiation of thrombolytic therapy, applying the above mentioned criteria. Those who underwent successful thrombolysis were grouped into group A. Those with failed thrombolysis -Group B. The following parameters were analyzed: Age, Gender, Smoking status, Drinking status, Diabetes mellitus, Systemic Hypertension, Location of Myocardial Infarction, Time interval between the onset of pain and the initiation of thrombolytic therapy, Killip grading. Patients with inferior wall myocardial infarction had a betterResults: outcome than anterior wall myocardial infarction. Alcohol, smoking and age were factors which inuence the outcome, but were not statistically signicant. Early thrombolysis had a better out come when compared to other predictors. Success rate was 64% in those patients thrombolysed within 4 hrs. from the onset of symptoms. Time window was found to be the most powerful factor inuencing the outcome of thrombolysis in patients with acute myocardial infarction. The successConclusion: rate was signicantly higher with a lower Killip grading and the outcome worsened as the grading increased.