Abstract :
Background: Cardiac arrhythmias are quite common in the setting of acute myocardial infarction. Ninety percent of
patients with acute myocardial infarction (AMI) have some cardiac rhythm abnormality, and 25% have cardiac conduction
disturbance within 24 hours of infarct onset. These are tachyarrhythmias, ventricular arrhythmias, and atrioventricular
block. A good correlation exists between the site of infarct and type of arrhythmias. Sinus bradycardia, sinoatrial escape
rhythms, Wenkebach type and complete heart block are usually associated with inferior wall myocardial infarction (IWMI).
Atrial premature contraction (APC) and ventricular premature contraction (VPC) are usually seen in anterior wall myocardial
infarction (AWMI). Methods: The present cross-sectional study was conducted on 100 consecutive cases of acute
myocardial infarction with arrhythmias attending as indoor emergency patients of Guru Nanak Dev Hospital attached to
Government Medical College, Amritsar were included. History, clinical examination and required investigations including
lipid profile, blood sugars, electrolytes, CPK-MB, ECG, and 2D-Echo were done. Results: Out of the hundred patients in
the study, males (57%) outnumbered females (43%). Most of the patients were found in the age group of 51-60 years
(34%). Smoking was the most significant risk factor (38%), followed by diabetes mellitus (35%), hypertension (30%) and
prior ischemic heart disease (28%). The majority (56%) of the patients had anterior wall myocardial infarction (AWMI),
followed by IWMI (24%), IWMI + RVMI (13%) and AWMI + IWMI (7%). Most of the arrhythmias (62%) developed during
initial 24 hours of admission, while 27% in next 24 hours and 11% after 48 hours of admission to hospital. The most
common arrhythmia observed was VPC (50%), followed by sinus tachycardia (48%), sinus bradycardia (16%), accelerated
idioventricular rhythm (9%), 3rd degree heart block (7%), ventricular tachycardia (6%), 1st degree Heart Block (5%), 2nd
degree Heart block (5%), ventricular fibrillation (4%), APC (4%) and AF (1%). Maximum incidence of VPC, sinus
tachycardia, ventricular tachycardia (VT) and ventricular fibrillation (VF) were recorded in AWMI, while the maximum
incidence of sinus bradycardia and AV block were observed in IWMI. Mortality was more common in patients developing
arrhythmias specifically VT, VF and heart blocks especially 2nd-degree heart block and 3rd-degree heart block.
Conclusion: Most of the patients with acute myocardial infarction develop some kind of arrhythmias which is an important
cause of morbidity in these patients, develop during the initial 24 hours of admission to the hospital. Most common
arrhythmias observed were VPC, followed by sinus tachycardia, AV block, bundle branch block, sinus bradycardia, VT, and
VF. VPC, sinus tachycardia, VT, and VF were more common in AWMI, while sinus bradycardia and AV block were more
common in IWMI. Diligent monitoring for arrhythmias and appropriate treatment can be life saving.
Keyword :
arrhythmia, acute myocardial infarction