Risk stratification

The amount of myocardial damage and the degree of left ventricular dysfunction, which may be limited by the presence of a patient infarct related artery, together with the extent of underlying coronary disease, influence prognosis after myocardial infarction.3,4 In the 1960s Killip and Kimball showed that the presence and increasing severity of cardiac failure predicted a poor outcome and that hospital mortality was more than 80% if cardiogenic shock developed.5 A decade later Norris developed an index including the patient's age, history of previous infarction, systolic blood pressure on admission, site of infarction, and radiographic evidence of cardiac enlargement or pulmonary congestion.6 Increasing age, a history of previous infarction, and radiographic evidence of cardiac failure and cardiomegaly were shown to be associated with a worse prognosis.

The extent of myocardial damage can now be estimated from straightforward, non-invasive investigations that can quantify the degree of ventricular dysfunction. Residual myocardial ischaemia and a tendency to ventricular arrhythmias also influence prognosis after infarction, and the investigation and assessment of all three are discussed below.

Extent of ventricular dysfunction

The degree …