Structure & Function of the Heart:
Risk factors for Coronary Artery disease:
Coronary Artery Disease:
Emergency Complications of Heart Attack:
Coronary Artery Bypass Grafting (CABG):
Rheumatic Fever and Heart Valve Diseases:
Heart Transplantation and Assisted devices
Blood tests for heart diseases
To reach a diagnosis, your physician requires information. Your medical history, the symptoms you report, and the physical examination he or she conducts are ways your physician obtains this information. In addition, your physician will order diagnostic tests to obtain more information about you. Blood tests are one of the tools that help your doctor to diagnose your heart condition or prepare you for a heart surgery. The value of diagnostic testing depends on factors such as need, what can be reasonably discovered, and risks posed, if any.
Blood tests are used to rule out or to help diagnose disease. Routine blood tests can detect the possible presence of a wide variety of conditions including various types of anemia, infections, and leukemia, to name only a few. The drawing of a small amount of blood into a vial usually takes only a few seconds and can be done in a laboratory, in your physician’s office, or in a hospital. Special preparations are not necessary. (Some tests require overnight fasting; others require no fasting at all. Follow your physician’s instructions.) Blood can be drawn from many sites. If only a drop or two is necessary, the blood usually is drawn from a fingertip and is placed in a small container called a capillary pipette. If more than a drop of blood is required, the person drawing it will select a vein, cleanse the skin over it with alcohol, and then gently insert a thin needle. Blood will pass through the needle into an attached sterile syringe. Then the needle is withdrawn and the puncture wound can be wiped again with an antiseptic. In most routine examinations, blood testing includes a complete blood cell count (CBC), a chemistry group, and blood lipids. Literally hundreds of other blood tests can be obtained. Common ones include coagulation studies (to determine the rate at which the blood thickens or clots). Your physician will choose the most appropriate tests for you. Below we describe in more detail some of the principal types of blood tests.
Complete Blood Cell Count (CBC)
The CBC is the most common blood test of all. It usually is part of a complete health checkup. The term "count" refers to the counting of each type of blood cell in a given volume of your blood. The CBC measures the amount of hemoglobin, the percentage of the sample that is composed of red blood cells (hematocrit), the number and kinds of white blood cells, and the number of platelets. CBC is very helpful in diagnosis and management of heart diseases as well as a lot of other diseases. For example, a patient who is complaining of shortness of breath can be diagnosed with heart failure. However his CBC might show very low hemoglobin signifying anemia which might be the real cause of his shortness of breath. If a rheumatic heart patient or a patient who have a mechanical heart valve is complaining of fever and his CBC comes with a high white blood cell count, this might point to infective endocarditis . Complete blood cell count is very useful especially when linked with other symptoms and signs. CBC is also done routinely before any heart surgical procedure.
Often automated, the blood chemistry group tests may include an analysis of electrolytes (sodium, potassium, chloride, and phosphorus) and glucose (blood sugar), a series of liver function tests (including studies for bilirubin), and tests for uric acid, creatinine (a kidney function test), and albumin (a major protein in the blood). Sometimes, different combinations of tests are used. Before your heart surgey, these tests are very usefully. Kidney function tests are very important before surgery, because if they are impaired, you will need special care during your surgery. Another important test is your blood sugar. If you are diabetic blood sugar test will be done very frequently after heart surgery to help to control your blood sugar and protect you against infection of your wound.
Another common blood test is for lipids. This test measures the blood level of fats including total cholesterol , high density lipoprotein (HDL) cholesterol, and triglycerides, all of which may be indicators of risk for coronary artery disease.
Erythrocyte Sedimentation Rate
This blood test, also called ESR, determines the rate at which red blood cells settle to the bottom of a container. If the cells settle faster than normal, this can suggest an infection, anemia, inflammation, rheumatoid arthritis, rheumatic fever , or one of several types of cancer.
Coagulation tests detect abnormal levels of substances in your blood that control the speed at which your blood clots. For example, tests of the partial thromboplastin time (PTT) and prothrombin time (PT) can help identify blood clotting diseases and liver diseases and are commonly used in monitoring patients taking blood thinning medications (anticoagulants). The INR is the test used to monitor warfarin therapy in patients with mechanical heart valves.
These include lactate dehydrogenase (LDH), creatine phosphokinase (CPK) and troponin. These test will help in diagnosis the cause of your heart attack. Thses enzymes are elevated in myocardial infarction .
It often is helpful to know the amount of a drug in the blood (in general or at a specific time), such as the heart drug digoxin (Lanoxin). Drug tests (there are many) can reveal this information precisely.
Arterial Blood Gas Analysis
This test measures the acidity (pH) of your blood and the amount of oxygen and carbon dioxide dissolved in it. The procedure differs somewhat from a standard blood test. Still, it takes only a few seconds and can be per- formed in a laboratory, a physician's office, or a hospital. The skin over the artery to be punctured is cleaned with an antiseptic and a local anesthetic is injected. (An artery is chosen rather than a vein, because the blood sample must be freshly oxygenated from the heart and lungs.) The selected artery, usually in the wrist, is punctured with a sterile needle attached to a disposable syringe. The interior of the syringe is oil-coated to prevent room air from contaminating the blood sample. The physician or technician draws a sample of blood and then removes the needle from the artery. The blood sample is transferred from the syringe into sterile tubes that are placed in a blood gas analyzer. After the blood sample has been drawn you will be asked to apply pressure to the puncture site and rest quietly for 15 minutes before resuming normal activities. Blood gases tests are very useful during your heart surgery and they are frequently done during your stay in the ICU after the operation.
To be of value, test results must be accurate. To help ensure dependability of blood tests, for ex- ample, solutions with known amounts of the substance being sought are interspersed with blood samples being analyzed. Another check on accuracy is the periodic testing of unknown samples prepared by other laboratories. In both cases, the results provide a way to judge accuracy (or inaccuracy) of testing procedures. Even with these precautions, however, errors can occur.
Symptoms and signs of heart disease:
NonInvasive diagnostic tests For heart disease:
Invasive Diagnostic Tests for heart disease:
Cardiac Arrythmias and Pacemakers:
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