Validity of myocardial infarction models.

Because of the importance of acute myocardial infarction, much effort has been made to develop a representative animal model. Clinical characteristics that have been sought in the models include sudden death, early and late tachyarrhythmias, slow cardiac rhythms and bundle blocks, and variable influence of location of infarction. Each of these characteristics has been found under some conditions and in some models, but it has not been possible to imitate the entire range of the human disease in a simple model. Each model has significant drawbacks in terms of nonhuman cardiac response to stress or drugs, different coronary artery physiology, convenience of study, or cost. In particular, the use of isolated tissue confuses the influences of hypoxia and ischemia. The models have been of great value to investigation in myocardial infarction, but more focus on physiological and biochemical mechanisms may help to avoid the errors inherent in the use of models.