As answered previously, the meds you are talking about are the clot-buster drugs. These are very potent agents that work to dissolve blood clots. Ideally, they only dissolve a clot that is blocking a coronary artery (heart attack), but they are not body part specific, so they will dissolve ANY clot in the body AND reduce the blood s ability to form any new clots as well, such as to stop bleeding. The use of these drugs is Highly effective in treating not only Heart attacks, but also certain strokes caused by blood clots (in certains patients and in certains circumstances). However, most experts agree that the better and safer course for heart attacks is balloon angioplasty or CABG if it is readily available. One of the biggest and most dangerous potential side effects of the use of clot buster drugs is catastrophic hemmorhage in the brain (hemmorhagic stroke), uncontrollable bleeding in the GI tract (such as from an ulcer), or other type of uncontrollable bleeding. For this reason, the use of these drugs needs to be in a tightly controlled environment with very close monitoring of a patient s condition. Due to their potential life threatening side effects, many patients are not eligible to receive those drugs. Now, in many areas of the US, there have been studies and pilot programs conducted where clot busters WERE administered in the pre-hospital setting. The guidelines for these programs included very strict exclusionary criteria in an effort to reduce the chances of a catrastrophic complication. I understand there has been some success that resulted from these programs, but I am not sure of the formal results of the studies, improved survival rates vs. complications, etc. In the grand scheme of things, the administration of clot busting drugs carries a high potential for life threatening complications. In the emergent prehospital setting, the focus is more on immediate stabilization and transport as well as initial screening to identify any problems that might make a patient ineligible for thrombolytic therapy (history of ulcers, recent surgery or trauma, etc.) and to alert the receiving hospital of the immenent arrival of a heart attack victim. The initial management of cardiac chest pain / ACI involves oxygen therapy, aspirin administration (proven dramatic impact on patient survival to discharge), acquisition of a base line 12-Lead ECG, control of any life threatening rhythm disturbances, relief of pain, etc. These activities are often carried out simultaneously with safe, rapid transport of the patient to the APPROPRIATE medical facility. Now, on a personal note. In the United States, the people you refer to are EMS professionals. Some are career folks, some are volunteer... depending on where they are located. But they are ALL well trained professionals (EMTs and Paramedics). Please realize that there is a great deal more that these people do besides drive the ambulance. Gone are the days of band-aids and powerful engines. EMS is recognized as an allied health profession.