6th March 2024

Complications

Following a myocardial infarction, patients are at risk of several complications. Early complications include: 

• Cardiac arrest commonly caused by ventricular fibrillation, the most common cause of death following MI 
• Cardiogenic shock is usually dependent on the myocardial infarct size 
• Bradyarrhythmia and heart block are common following inferior myocardial infarction 
• Tachyarrhythmias, including ventricular tachycardia and ventricular fibrillation, as mentioned above 

Late complications include: 

• Chronic heart failure due to dysfunctional myocardium following infarct
• Left ventricular aneurysm due to weakened myocardium. This is associated with persistent ST elevation and left ventricular failure. There is an increased risk of stroke therefore, patients need anticoagulation
• Left ventricular free wall rupture is most common with anterior myocardial infarction. Presentation is with acute heart failure secondary to cardiac tamponade and is a medical emergency 
• Mitral regurgitation is common with inferoposterior infarction and occurs due to ischaemia or rupture of the papillary muscle 
• Pericarditis / Dressler syndrome may present following a large transmural infarct. It is thought to be due to an autoimmune reaction against antigenic proteins formed as the myocardium recovers.