Mechanical complications of myocardial infarction

Acute myocardial infarction is responsible for a significant proportion of morbidity and mortality in patients with ischaemic heart disease. Apart from cardiogenic shock, important mechanical complications include myocardial rupture, mitral regurgitation, mural thrombosis, left ventricular true aneurysm and pericarditis. Such patients are likely to be older (more than 60 years of age), especially women with hypertension, single-vessel disease, first episode of transmural infarction, smaller area of infarction, and/or delayed thrombolytic therapy. The incidences of all these complications have significantly reduced due to availability of reperfusion techniques. Myocardial rupture includes rupture of the left ventricular free wall, interventricular septum or papillary muscles, which can occur within few hours or days after infarction and emergency surgery is indicated. Lateral displacement of papillary muscles due to post-infarctional left ventricular remodelling is the main factor for ischaemic mitral regurgitation; some patients would require mitral valve repair or replacement. Mural thrombosis results from an abnormal flow and local hypercoagulable state and requires thrombolytic therapy or even surgical excision. Post-infarctional fibrosis is also responsible for formation of ventricular apical aneurysms and depending on the clinical status, reconstructional surgery may be required. Dressler's syndrome is a rare occurrence of fibrinous pericarditis accompanied by constitutional symptoms, which responds to immunomodulation.