As regards reperfusion therapy in patients with acute myocardial infarction, the general belief today is that early recanalization of the infarct-related artery--using either thrombolytic therapy or direct mechanical thrombolysis with angioplasty, and undertaken within 6 hours since the onset of ischaemia--can reduce the extent of necrosis, will reduce both mortality during hospitalization and one-year mortality, and will favourably limit regional expansion of the left ventricle affected by the infarction. Drawbacks include apparent reperfusion injury to the myocardium with possible impact on patients' mortality within the first 24 hours. The importance of reperfusion injury has not been fully established as yet. Delayed recanalization within 12 hours can only occasionally reduce the extent of necrosis (in specific cases where the development of necrosis has not yet been completed). The effect on patients' mortality remains unclear. While delayed institution of thrombolytic therapy must be considered on a case-by-case basis, it is not contraindicated. It does not seem advantageous to initiate thrombolytic therapy within 12 to 24 hours since the onset of ischemia. In such cases, percutaneous transluminal angioplasty may be more appropriate, but practical considerations and the costs involved render this option virtually unfeasible at present. However, delayed recanalization of the infarct-related artery using the latter method may exert a favourable effect on left ventricular remodeling. It should be noted it is no longer a mechanism of direct myocardial protection, as is the case in the early phase of infarction.

Keywords: Angioplasty, Balloon, Coronary; Humans; Myocardial Infarction /drug therapy/; Myocardial Reperfusion; Thrombolytic Therapy; Time Factors