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 TESTS ASSOCIATED WITH CARDIAC DISORDERS
PHARMD GURU Page 2 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 1012cells/liter.  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%.

PHARMD GURU Page 4 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. CREATINE KINASE:  Creatine kinase (CK/CPK) is an enzyme expressed in a number of tissues. Function: it catalysis the conversion of creatine to phosphocreatine degrading ATP to ADP.  The CK enzyme consists of two subunits, B (brain type) or M (muscle type) Three different Isoenzymes: CK-MM, CK-BB and CK-MB.  CK-BB occurs mainly in tissues, rarely of any significance in the bloodstream.  Skeletal muscle expresses CK-MM (98%) and low levels of CK-MB (1%).  The myocardium has CK-MM at 70% and CK-MB at ~30%.