heart and blood vessel disorders
Acute Coronary Syndromes (Heart Attack; Myocardial Infarction; Unstable Angina)
Diagnosis of Acute Coronary Syndromes
Electrocardiography (ECG) Blood tests Whenever a man over age about 30 or a woman over age about 40 reports Chest Pain , doctors usually consider the possibility of an acute coronary syndrome. But several other conditions can cause similar pain, such as Electrocardiography and certain blood tests can usually confirm the diagnosis within a few hours. Electrocardiography is the most important initial diagnostic procedure when doctors suspect an acute coronary syndrome. This procedure provides a graphic representation of the electrical current producing each heartbeat. In many instances, it immediately shows that a person is having a heart attack. Abnormalities detected by ECG help doctors determine the type of treatment needed. The abnormalities on ECG also help show where the heart muscle was damaged. If a person has had previous heart problems, which can alter the ECG, the most recent damage may be harder for doctors to detect. Such people should carry a small copy of their ECG in their wallets, so that if they have symptoms of an acute coronary syndrome, doctors can compare the previous ECG with the current ECG. If a few ECGs recorded over several hours are completely normal, doctors consider a heart attack unlikely. Measuring levels of certain substances (called cardiac markers) in the blood also helps doctors diagnose acute coronary syndromes. These substances are normally found in heart muscle but are released into the blood only when heart muscle is damaged or dead. Most commonly measured are heart muscle proteins called troponin I and troponin T and an enzyme called CK-MB (creatinine kinase, myocardial band subunit). Levels in the blood are elevated within 6 hours of a heart attack and remain elevated for several days. Levels of cardiac markers are usually measured when the person is admitted to the hospital and at 6- to 12-hour intervals for the next 24 hours. When ECG and cardiac marker measurements do not provide enough information, Echocardiography and Other Ultrasound Procedures or Other tests may be done during or shortly after hospitalization. These tests are used to determine whether a person needs additional treatment or is likely to have more heart problems. For instance, a person may have to wear a Holter Monitor: Continuous ECG Readings , which records the heart’s electrical activity for 24 hours. This procedure enables doctors to detect whether the person has abnormal heart rhythms (arrhythmias) or episodes of inadequate blood supply without symptoms (silent ischemia). An During an exercise tolerance (stress) test, the person walks at an increasingly rapid pace on a treadmill. The person wears a blood pressure cuff (the black arm band), which monitors blood pressure throughout the procedure. A video monitor displays the pulse and ECG. The results help determine the presence of coronary artery disease. Video from Video Tape Library, Ltd. 