Arrhythmia and its risk factors post myocardial infarction: A prospective study

Objectives: To determine the occurrence of arrhythmia and its associated risk factors in the first week after acute myocardial infarction (MI). Methods: A total of 100 patients with acute MI were recruited, who were followed up for one week to determine the occurrence of arrhythmia and its association with electrolyte disturbances, left ventricular ejection fraction (LVEF), and demographic factors. Univariate and multivariate logistic regression was used to identify significant risk factors of arrhythmia. Results: Among 100 cases, arrhythmia was seen in 27 patients. Sinus tachycardia was the commonest, followed by ventricular premature beats and sinus bradycardia. Ejection fraction, serum calcium and magnesium were significantly different between non-arrhythmia and arrhythmia patients (P<0.05). Multivariate logistic regression analysis showed that ejection fraction was an independent significant risk factor of arrhythmia. Patients with ejection fraction >40% had a significantly lower risk of arrhythmia with an adjusted odds ratio of 0.22 (95% CI: 0.08 to 0.64). Conclusions: Arrhythmia is common in the first week after myocardial infarction. The type of arrhythmia and the type of block may depend on the heart muscles involved during myocardial infarction. Ejection fraction is a risk factor that may affect the occurrence of arrhythmia.