Tiêu đề 14. TESTS ASSOCIATED WITH CARDIAC DISORDERS.pdf ✅

PHARMD GURU Page 1 The heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients, as well as assisting in the removal of metabolic wastes. In humans, the heart is located between the lungs, in the middle compartment of the chest. CARDIAC DISORDERS:  Coronary heart disease  Stroke  Other cardiovascular diseases  Hypertensive heart disease  Inflammatory heart disease  Rheumatic heart disease. CARDIAC FUNCTION TESTS: There are 3 types of cardiac function tests. They are: 1) Laboratory tests 2) Cardiac biomarkers 3) Non laboratory tests. 1) LABORATORY TESTS:  White blood cell count (WBC) is the number of white blood cells in a volume of blood. Normal range is generally between 4,300 and 10,800cells per cubic millimeter (cmm).  White blood cell (WBC) differential count. White blood count is comprised of several different types that are differentiated, or distinguished, based on their size and shape. The cells in a differential count are lymphocytes, monocytes, eosinophils and basophils.  Red cell count (RBC) signifies the number of red blood cells in a volume of blood. Normal range: 4.2 to 5.9 million cells/cmm. This can also be referred to as the erythrocyte count and can be expressed in international units as 4.2 to 5.9 x 1012 cells/liter. TESTS ASSOCIATED WITH CARDIAC DISORDERS
PHARMD GURU Page 2  Hemoglobin (Hb). This is the amount of hemoglobin in a volume of blood. Hemoglobin is the protein molecule within red blood cells that carries oxygen and gives blood its red color. Normal ranges: 13 to 18 gm/dl for men. 12 to 16 gm/dl for women.  Haematocrit (Hct). This is the ratio of the volume of red cells to the volume of whole blood. Normal range: 42% to 52% for men. 37% to 47% for women. This is usually measured by spinning down a sample of blood in a test tube, which causes the red blood cells to pack at the bottom of the tube.  Mean corpuscular volume (MCV) is the average volume of a red blood cell. This is a calculated value derived from the haematocrit and red cell count. Normal range may fall between 80 to 100 fentoliters (a fraction of one millionth of a liter).  Mean Corpuscular Hemoglobin (MCH) is the average amount of hemoglobin in the average RBC. This is a calculated value derived from the measurement of hemoglobin and the red cell count. Normal range: 27 to 32 pictograms.  Mean Corpuscular Hemoglobin Concentration (MCHC) is the average concentration of hemoglobin in a given volume of red cells. This is a calculated volume derived from the hemoglobin measurement and the haematocrit. Normal range: 32% to 36%.  Red Cell Distribution Width (RDW) is a measurement of the variability of red cell size and shape. Higher numbers indicate greater variation in size. Normal range: 11 to 15.  Platelet count. The number of platelets in a specified volume of blood. Platelets are not complete cells, but actually fragments of cytoplasm (part of a cell without its nucleus or the body of a cell) from a cell found in the bone marrow called a megakaryocyte. Platelets play a vital role in blood clotting. Normal range: 1, 50,000 to 4, 00,000 Cells/mm3. 2) CARDIAC BIOMARKERS:  Cardiac biomarkers are substances that are released into the blood when the heart is damaged or stressed.  Measurement of these biomarkers is used to diagnose, monitor.
PHARMD GURU Page 3  Cardiac biomarker tests are used to help and detect the presence of ACS and cardiac ischemia and to evaluate their severity as soon as possible so that appropriate therapy can be initiated.  The current biomarker test of choice for detecting heart damage is troponin.  Other cardiac biomarkers are less specific for the heart.  Current cardiac biomarker tests used to help diagnose, evaluate, and monitor individuals suspected of having acute coronary syndrome (ACS) include: 1. Troponin I or T 2. CK 3. CK-MB.  Other biomarker tests that may be used: 1. Myoglobin 2. BNP (or NT-proBNP) — although usually used to recognize heart failure, an increased level in people with ACS indicates an increased risk of recurrent events. TROPONIN:  Protein found in skeletal and contractual fibers of the heart (cardiac muscle).  Troponin I and T are cardiac specific.  Normal: 0-0.3 ng/ml  Timing: Earliest rise: 3-4 hrs Peak: 10-24 hrs Return to Normal: 1-3 wks. Elevated Troponin: Patients with elevated Troponin I levels, normal CK-MB and no ST elevation has an increased risk of death.  Useful marker for post-op cardiac surgery patient.  Troponin has three subunits, TnC, TnT, and TnI.  Troponin-C binds to calcium ions to produce a conformational change TnI.  Troponin-T binds to tropomyosin, interlocking them to form a troponintropomyosin complex.  Troponin-I binds to actin in thin myofilaments to hold the troponintropomyosin complex.