A Study of Arrhythmias in First 48 Hours of Acute Myocardial Infarction in a Tertiary Care Hospital

• Main Authors: Mohini Singh, Monika Ghai, SR Ramakrishnan
• Format: Article
• Language: English
• Published: JCDR Research and Publications Private Limited 2020-05-01
• Series: Journal of Clinical and Diagnostic Research
• Subjects: acute coronary syndrome; bradyarrhythmias; cardiac biomarkers; tachyarrhythmia
• Online Access: https://jcdr.net/articles/PDF/13685/43332_F(SHU)_PF1(AG_KM)_PFA(KM)_PB(AG_KM)_PN(SL).pdf
• ISSN: 2249-782X; 0973-709X

Introduction: Myocardial infarction is defined as a clinical or pathologic event caused by myocardial ischemia in which there is evidence of myocardial injury or necrosis. The diagnosis of myocardial infarction is established by typical symptoms, cardiac biomarkers, electrocardiographic changes, or imaging evidence of new regional wall motion abnormality or new loss of viable myocardium. Arrhythmias are well-recognised complications of Acute Myocardial Infarction (AMI) and are important risk factors for mortality in both men and women, across a wide age range. Aim: To analyse the incidence of arrhythmias in acute myocardial infarction with respect to the type, age, gender distribution, location and extension of AMI and to interpret effect of arrhythmias on mortality and morbidity in patents in the first 48 hours of AMI. Materials and Methods: This observational study included 120 patients admitted within one hour of chest pain in Cardiac care unit at Sri Ramachandra Institute of Higher Education and Research Chennai, Tamil Nadu, India from February 2017 to April 2018 after fulfilling the inclusion criteria. Diagnosis of AMI with arrhythmia was made on clinical features, electrocardiography, cardiac biomarkers and echocardiogram. For statistical analysis of data, Statistical Package for Social Sciences (SPSS 16.0 version) was used. Results: In this study of 120 patients, 74 (61.7%) were males and 46 (38.3%) were females (post-menopause) and highest incidence of arrhythmia was noted in the age group of 61-70 years (32.5%). A total of 71 patients (59.2%) presented with chest pain (p<0.001) and 59.2% had type 2 diabetes. Anterior Wall Myocardial Infarction (AWMI) was observed in 29.16%, followed by Inferoposterior Wall Myocardial Infarction (IPWMI) which was observed in 21.6%. A total of 40.8% had arrhythmias within first hour of hospitalisation. In this study, ventricular premature complex was the most common arrhythmia, observed in 29.2%, followed by sinus tachycardia (20%). Tachyarrhythmias were more frequently observed in anterior infarction whereas bradyarrhythmias were more frequently observed in inferior infarction. 30.8% of patients had ejection fraction of <40%. Overall, mortality was 10% {5.8% in AWMI and 1.7% in IPWMI}. Cardiac biomarkers and left ventricular function were good predictors of extent of infarction (p<0.001). Ten deaths were due to arrhythmias and two secondarily to cardiogenic shock. Conclusion: In this study, it was observed that incidence of myocardial infarction increases with age and was noted more in males than females and in females it was noted more in post-menopausal group. Most common type of arrhythmias observed were ventricular premature complexes and sinus tachycardia and significant number of patients had arrhythmias during the first hour of hospitalisation. Overall, mortality rate was 10% and cardiac biomarkers and left ventricular function are good predictors of infarct size.