[Thrombolytic treatment of myocardial infarction. Data on the limitation of infarction size and left ventricular function]

Abstract

Since its introduction in cardiovascular therapeutics, thrombolysis has established itself as an effective procedure of coronary reperfusion during the acute phase of myocardial infarction. Large scale clinical trials have demonstrated a clear cut reduction in mortality providing that the treatment is administered sufficiently early after the onset of symptoms. This reduced mortality is probably related to the limitation of infarct size and the conservation of ventricular function even though this relationship is not always analysed. Studies of infarct size and left ventricular function are difficult to perform and this is reflected in the number of different methods proposed. Apart from coronary reperfusion and its timing, other factors influence the definite size of the infarct, such as the development of a collateral circulation, the existence of cellular reperfusion lesions and the occurrence of reocclusion. The infarct size may be assessed by a number of methods, some simple (enzymes, electrocardiogram) but relatively inaccurate, others more promising but difficult to perform and more costly. Thallium 201 scintigraphy seems to be the best available method and our experience is based on these results. The reference method for the evaluation of left ventricular function is angiography but angioscintigraphy also provides information on global and regional function, the regional study being particularly valuable in the analysis of thrombolytic drug efficacy. A review of the literature shows that thrombolysis is associated with a reduction in infarct size compared with conventional therapy and with conservation of left ventricular function whichever thrombolytic agent is used.(ABSTRACT TRUNCATED AT 250 WORDS)