Both of them are slangs not a medical term, strictly speaking. The precise word is acute myocardial infarction. HEART STROKE: acute severe, reflecting the infarction of the vascular territory that is put at risk by a stenosis or occlusion of a feeding vessel. HEART ATTACK:Heart attack: The death of heart muscle due to the loss of blood supply. The loss of blood supply is usually caused by a complete blockage of a coronary artery, one of the arteries that supplies blood to the heart muscle. Death of the heart muscle, in turn, causes chest pain and electrical instability of the heart muscle tissue. ARTICLE: Late last year (just in time for Dick Cheney to have his cardiac problem,) doctors changed the way they define myocardial infarction (heart attack). The new definition includes changes in the cardiac enzyme troponin. Troponin is a more sensitive indicator of heart cell damage than the traditional cardiac enzyme used for diagnosing heart attacks (i.e., MB CK levels). By including changes in troponin levels in defining heart attack, many more patients who would previously been diagnosed as having unstable angina will now be diagnosed as having a heart attack. This is what happened in the case of Dick Cheney in November, 2000. Estimates are that, thanks to these new criteria, an additional 250,000 patients in the U.S. will be diagnosed with heart attacks this year.