Short-term outcome of acute inferior wall myocardial infarction with emphasis on conduction blocks: a prospective observational study in Indian population

OBJECTIVE: The primary aim of the present study was to evaluate the complications, particularly conduction blocks, subsequent morbidity and mortality, and effect of thrombolytic therapy in Indian patients with inferior wall myocardial infarction (IWMI). METHODS: This was a prospective, observational, single-center study conducted at LPS Institute of Cardiology, Kanpur, from December 2011 to May 2014. Patients who presented with typical chest pain and were subsequently diagnosed by standardized diagnostic criteria as having IWMI were enrolled. Patients were grouped on basis of conduction abnormalities, right ventricular (RV) infarction and thrombolytic treatment. Each group was analyzed for comparison of complication profile and mortality. RESULTS: Of 573 patients with IWMI enrolled in the study (mean age: 58.90±12.3 years), 81.2% were male, 225 (39.3%) had conduction blocks, and 189 (32.9%) had RV infarction. In patients with conduction blocks, mortality occurred in 27 patients (12.0%) in contrast to 3.4% of patients without conduction block (p<0.03). Also, there were 27 cases of in-hospital mortality in patients with RV infarction compared with 9 cases in patients without RV infarction (p<0.01). Thrombolytic therapy significantly reduced mortality in patients with IWMI (p<0.001). A significant reduction was observed in cardiogenic shock (p=0.002), severe mitral regurgitation (p=0.007), and left ventricular failure (p<0.001) in patients undergoing thrombolytic therapy. CONCLUSION: In Indian patients with IWMI, incidence of conduction blocks was higher than previously reported studies. Major complications such as atrioventricular block and RV infarction are associated with increased mortality and poor clinical outcomes. Thrombolytic therapy has a beneficial role in reduction of mortality rate and other complications.