I was curious how animals such as rats, dogs, monkeys etc might be given heart attacks, and found the following, which may be of interest to others who are similarly curious.

"Myocardial infarctions (MIs) in rats were originally induced by the sequential administration of subcutaneous isoproterenol causing diffuse myocardial necrosis. Subsequent investigators used an electrocautery technique applied to the epicardial surface to induce small, focal infarctions. Soon thereafter, Pfeffer et al developed the rat coronary ligation model that became perhaps the most widely used heart failure and MI model in the decades to follow."

• https://www.ahajournals.org/doi/full/10.1161/circheartfailure.108.839761

Apparently transgenic animals can also be used, bred to carry mutated genes so that they develop hypertension, hypertrophy and subsequent heart failure.