Abstract
Background /Aim: Studies of patients with myocardial infarction and Bundle branch block have reported high mortality rate and poor prognosis. To document the frequency of Bundle branch block and their influence on prognosis in patients with acute myocardial infarction.
Patients & Methods: This is case –control study of 42 patients with acute myocardial infarction and bundle branch block (case subject) and 42 patients with acute myocardial infarction and with out block (control subject) .Patients admitted to the coronary care unit were searched to identify those with documented acute myocardial infarction complicated by the presence of bundle branch block. Conduction defects were classified as follow: complete left bundle branch block (LBBB); right bundle branch block (RBBB); right bundle and left anterior fascicular block (RBBB+LAFB); right bundle and left posterior fascicular block(RBBB+LPFB). And all patients treated with Thrombolytic therapy (Streptokinase or t-PA tissue –type plasminogen).
Results: In 42 patients with acute myocardial infarction complicated by bundle branch block, most common types of block were LBBB (38%) and RBBB+LAFB (33.4%).
Patients with RBBB + LPFB had a higher mortality than patients with other intra ventricular conduction defect (42% VS 26%,p<0.025). Hospital mortality was directly related to the degree of heart failure only ,(8%) of patients with class I-II heart failure died, compared to (47%) of Patients with class III-IV heart failure (p < 0.001). The hospital mortality were higher in patients with bundle branch block than in those without block . (26 % VS. 12% p>0.001).
Conclusion: The occurrence of Bundle branch block in acute myocardial infarction indicate that infarction may be extensive and may result in cardiac failure or death.
Keyword: Electrocardiography (ECG), Myocardial infarction (MI), Left bundle branch block (LBBB), Right bundle branch block (RBBB).
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