Articles on Medical Diseases and Conditions

Entries for the ‘Cardiac Diseases’ Category

Creatine Kinase (CK)

Creatine kinase (CK) is found in heart muscle, skeletal muscle, and brain. It is elevated at some time in about 90%-93% (literature range, 65%-100%) of patients with acute MI. In acute MI, CK behaves similarly to AST. In addition, elevations have also been reported in myocarditis and also in some patients with tachyarrhythmias (mostly ventricular) […]

Hydroxybutyric Acid Dehydrogenase (HBD)

HBD has been used as a substitute for LDH-1 (heart) isoenzyme measurement. Actually, HBD is total LDH that is forced to act on a a-ketobutyric acid substrate instead of pyruvic or lactic acid. Under these conditions, LDH-1 and LDH-2 show relatively greater activity than LDH-5, so that HBD therefore indirectly measures LDH-1 (heart) activity. However, […]

Lactic Dehydrogenase

Lactic dehydrogenase (LDH) values refer to total serum LDH. Total LDH levels are elevated at some time in 92%-95% (literature range, 82%-100%) of patients with acute MI. Statistics for sensitivity in acute MI refer to multiple sequential LDH specimens and are therefore not valid for any single determination. In acute MI, LDH becomes elevated 24-48 […]

Aspartate Aminotransferase (AST)

Certain enzymes are present in cardiac muscle that are released when tissue necrosis occurs. Serum aspartate aminotransferase (AST, formerly oxaloacetic transaminase, or SGOT) is elevated at some time in 90%-95% of acute MI patients (literature range, 87%-97%). These statistics for sensitivity of the AST in acute MI are based on multiple sequential AST determinations and […]

Tests in Acute Myocardial Infarction

Electrocardiogram, white blood cell count, and erythrocyte sedimentation rate An electrocardiogram (ECG) is the most useful direct test available. Approximately 50% of acute MIs show unequivocal changes on the first ECG. Another 30% have abnormalities that might be due to acute infarct but that are not diagnostic, because the more specific changes are masked or […]

Myocardial Infarction (MI)

Clinical signs and symptoms are extremely important in both suspicion and diagnosis of myocardial infarction (MI). The type of pain, its distribution, and its response to nitroglycerin may be very characteristic. However, it may not be easy to differentiate the pain of angina from that of acute infarct; in addition, 20%-30% (literature range, 1%-60%) of […]