Clinical consequences of MI

About 15% of patients experience sudden death (0-2hr) after infarction, most presumably secondary to a fatal arrhythmia. Of patients who survive the acute event, 70-75% subsequently develops complications. (Thus no complications in 10-15%)

Early restoration of blood flow through the occluded vessel responsible for the infarct by thrombolysis or balloon angioplasty provides a generally better prognosis.

Complications: depends on the size and location of the necrosis as well as the reserve of functional myocardium…

Arrhythmias – 75-95% of complications

Congestive heart failure – 60% of complications

Cardiogenic shock (usually seen with >40% of LV infracted) – 10-15% of complications

Ventricular rupture within the first 10 days (median, 4-5 days):

• Rupture of the free wall causes pericardial haemorrhage and tamponade

• Rupture of the septum produces a left to right shunt with R. heart volume overload

Rarely papillary muscle infarction with or without rupture, often causing mitral valve dysfunction

Fibrinous-to-hemorrhagic pericarditis, common 2-3 days postinfarction (usually not clinically significant

Mural thrombosis in a non-contractile area with risk of peripheral embolization

Deformation of a large area of transmural infarction (expansion), which may heal into a ventricular aneurysm, both of which are prone to mural thrombosis

Repetitive infarction (extension)

Overall mortality in the first year is 30% and thereafter 5-10% per year.

Category: Medicine Notes