Unstable Angina and Myocardial Infarction (See also Chaps. 238 and 239) Patients with these acute ischemic syndromes usually complain of symptoms similar in quality to angina pectoris, but more prolonged and severe. The onset of these syndromes may occur with the patient at rest, or awakened from sleep, and sublingual nitroglycerin may lead to transient or no relief. Accompanying symptoms may include diaphoresis, dyspnea, nausea, and light-headedness. The physical examination may be completely normal in patients with chest discomfort due to ischemic heart disease. Careful auscultation during ischemic episodes may reveal a third or fourth heart sound, reflecting myocardial systolic or. | Chapter 013. Chest Discomfort Part 3 Unstable Angina and Myocardial Infarction See also Chaps. 238 and 239 Patients with these acute ischemic syndromes usually complain of symptoms similar in quality to angina pectoris but more prolonged and severe. The onset of these syndromes may occur with the patient at rest or awakened from sleep and sublingual nitroglycerin may lead to transient or no relief. Accompanying symptoms may include diaphoresis dyspnea nausea and light-headedness. The physical examination may be completely normal in patients with chest discomfort due to ischemic heart disease. Careful auscultation during ischemic episodes may reveal a third or fourth heart sound reflecting myocardial systolic or diastolic dysfunction. A transient murmur of mitral regurgitation suggests ischemic papillary muscle dysfunction. Severe episodes of ischemia can lead to pulmonary congestion and even pulmonary edema. Other Cardiac Causes Myocardial ischemia caused by hypertrophic cardiomyopathy or aortic stenosis leads to angina pectoris similar to that caused by coronary atherosclerosis. In such cases a loud systolic murmur or other findings usually suggest that abnormalities other than coronary atherosclerosis may be contributing to the patient s symptoms. Some patients with chest pain and normal coronary angiograms have functional abnormalities of the coronary circulation ranging from coronary spasm visible on coronary angiography to abnormal vasodilator responses and heightened vasoconstrictor responses. The term cardiac syndrome X is used to describe patients with angina-like chest pain and ischemic-appearing ST-segment depression during stress despite normal coronary arteriograms. Some data indicate that many such patients have limited changes in coronary flow in response to pacing stress or coronary vasodilators. Despite the possibility that chest pain may be due to myocardial ischemia in such patients their prognosis is excellent. Pericarditis See also Chap. 232 The
