Post-MI Complications

Mechanical Complications

Treatment for mechanical post-MI complications includes vasodilators and ACE inhibitors, as well as blood thinners in cases which have thrombi. 

• Papillary Rupture & Mitral Regurgitation: Transient MR occurs in 13-45% of patients and typically requires no treatment. Papillary muscle rupture (1%) presents within the first day, and presents with a holosystolic murmur, pulmonary edema, and cardiogenic shock. Chest x-ray may show pulmonary edema, and an echo with color flow can diagnose the rupture. 
• Septal Rupture: Typically present within 24 hours, 0.2% occurrence rate. Typically present with acute onset chest pain and a new holosystolic murmur. A ventricular conduction delay may also be present. Treatment is surgical, however while waiting consider vasodilators to decrease left to right shunting.
• Ventricular Free Wall Rupture: Three types of rupture exist; Type 1 present within 24 hours with a full thickness rupture, Type 2 present 1-3 days after MI with slow erosion of the myocardium, and Type 3 presents later as the area surrounding the infarcted tissue breaks down. Patients present with acute onset chest pain, JVD, pericardial friction rub, low voltage EKG, and tamponade. 
• Aneurysm: Thinning of the ventricular wall creating a bowed wall which is at risk for thrombus formation or rupture. The aneurysm can progress to dilated cardiomyopathy, may be silent, or produce a "to and fro" murmur and can be diagnosed by CT or echocardiogram. Occurs in 1-5% of MI patients in up to 6 weeks, and 1/3 of cases is fatal. 
• Left Ventricular Failure

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Ischemic Complications

• Post-infarct Angina: Chest pain after an ischemic event, could be secondary to vasospam
• Infarct Extension: Persistent thrombi causing additional infarction within the same area, usually associated with fibrinolytic therapy. 
• Recurrent Infarction: New thrombi causing a new area of infarction.
• Re-occlusion: Fibrinolytic therapy has a 5-10% while PCI has a 3% re-occlusion rate. Most patients present within 30 days, and typically associated with medication noncompliance. 

Pericarditis

• Inflammatory Pericarditis
• Dressler's Syndrome: Autoimmune reaction to myocardial antigens, presenting 2-8 weeks after MI.