Cardiovascular System

5K -- Select 3 of the 10 procedures types and report on it.5K -- Select 3 of the 10 procedures types and report on it.

BIO120: Medical Terminology PROF: Rashidah Abdullah

29 September 2009 JUAN

STRUCTURES HeartHeart ArteriesArteries VeinsVeins Functions pumps blood throughout the

entire body to transport nutrients, oxygen, and wastes.

diagnostic procedures Cardiac Enzymes Stress Tests Thrombolytic therapy

Cardiac Enzymes Enzymes are biochemical catalysts.

enzymes are proteins made of amino acids that are necessary to the body’s structure, function, regulation and help chemical reactions.

Cardiac Enzymes Troponin (important enzyme) it plays

a central role in how heart muscles contract. This enzyme control how the heart muscle responds to the signal received for contraction, and regulate the force with which the muscle contracts.

Creatine Phosphokinase (CPK) gives need energy for movement by the heart.

Why are cardiac enzymes important and what can the tell us?.

For example: When heart muscle is damaged in the case of a heart attack, high concentrations of cardiac enzymes are released into the blood stream.

Death or damage to heart muscle Death or damage to heart muscle cells leads to disintegration of heart cells leads to disintegration of heart cell membranes, which are the outer cell membranes, which are the outer coats of muscles cells. Loss of cell coats of muscles cells. Loss of cell membranes results in a “leaking” of membranes results in a “leaking” of cardiac muscle enzymes into the cardiac muscle enzymes into the blood blood

For heart attacks, measuring the levels of cardiac enzymes in the blood is a common test for the diagnosis of a heart attack and the amount the damage done to the heart; the medical field considers the measurement of cardiac enzyme levels in the blood to be a reliable test for a heart attack.

The Troponin test is considered the most accurate cardiac enzyme test in the diagnosis of a heart attack.

Troponin T and I These are contractile proteins of the

myofibril. The cardiac isoforms are very specific for cardiac injury and are not present in serum from healthy people. Cardiac troponins are the preferred markers for detecting myocardial cell injury.

Troponin I (cTnI) or T (cTnT) are the forms frequently assessed. 

Rises 2 - 6 hours after injuryPeaks in 12 - 16 hours cTnI stays elevated for 5-10 days, cTnT for 5-14 days

Creatine Kinase (creatine phosphokinase)

This enzyme is found in heart muscle (CK-MB), skeletal muscle (CK-MM), and brain (CK-BB).  Creatine kinase is increased in over 90% of myocardial infarctions. However, it can be increased in muscle trauma, physical exertion, postoperatively, convulsions, delirium tremens and other conditions.

Time sequence after myocardial infarction

begins to rise 4-6 hourspeaks 24 hoursreturns to normal in 3-4 days

Another protein, Another protein, myoglobin, may may be tested along with cardiac be tested along with cardiac enzymes to diagnose heart enzymes to diagnose heart attack.attack.

In other words.- enzyme studies are done to:

Determine whether you are having a heart attack or a threatened heart attack (unstable angina) if you have chest pain, shortness of breath, nausea, sweating, and abnormal electrocardiography results.

Stress Tests The exercise stress test also

called: exercise electrocardiogram, treadmill test, graded exercise test or stress ECG. It usually involves walking on a treadmill or pedaling a stationary bike at increasing levels of difficulty, while electrocardiogram monitors heart rate, and blood pressure.

different types of stress tests: Dobutamine or Adenosine Stress

Test: This test is used in people who are unable to exercise. A drug is given to make the heart respond as if the person were exercising

Stress echocardiogram: An echocardiogram (often called "echo") is a graphic outline of the heart's movement. A stress echo can accurately visualize the motion of the heart's walls and pumping action when the heart is stressed; it may reveal a lack of blood flow that isn't always clear on other heart tests

Nuclear stress test A very small and harmless amount of radioactive substance is injected into the patient.

This creates clear pictures of the heart tissue on a monitor. These pictures are done both at rest and after exercise.

In conclusion, Stress testing is used for diagnosis of coronary artery disease (CAD) and for risk stratification and monitoring of patients with known CAD. In patients with CAD, a blood supply that is adequate at rest may be inadequate when cardiac demands are increased by exercise or other forms of stress. Stress testing is less invasive and less expensive than cardiac catheterization, and it detects pathophysiologic abnormalities of blood flow; however, it is less accurate for diagnosis in patients with a low pretest likelihood of CAD.

Stress testing uses graded exercise in a supervised session to assess the heart's response to increases in its workload

Thrombolytic therapy A thrombus is a blood clot that

forms in a vessel and remains there. An embolism is a clot that travels from the site where it formed to another location in the body. Thrombi or emboli can lodge in a blood vessel and block the flow of blood in that location depriving tissues of normal blood flow and oxygen. This can result in damage, destruction (infarction), or even death of the tissues (necrosis) in that area.

Thrombus Thrombolytic therapy is the use of

drugs to break up or dissolve blood clots, which are the main cause of both heart attacks and stroke.

Thrombolytic medications are approved for the immediate treatment of stroke and heart attack. The most commonly used drug for thrombolytic therapy is tissue plasminogen activator (tPA).

A blood clot can block the arteries to the heart. This can cause a heart attack, when part of the muscle dies due to a lack of oxygen being delivered by the blood.

Thrombolytics work by dissolving a major clot quickly. This helps restart blood flow to the heart and helps prevent damage to the heart muscle. Thrombolytics can stop a heart attack that would otherwise be deadly.

The drug restores some blood flow to the heart in most patients. However, the blood flow may not be completely normal and there may still be a small amount of muscle damaged.

Thrombolytic therapy uses drugs called thrombolytic agents, such as alteplase (Activase), anistreplase (Eminase), streptokinase (Streptase, Kabikinase), urokinase (Abbokinase), and tissue plasminogen activator (TPA) to dissolve clots. These drugs are given as injections.

sourcesource Fischbach FT, Dunning MB III, eds. (2004). Manual of Laboratory and Diagnostic Tests,

7th ed. Philadelphia: Lippincott Williams and Wilkins. http://www.webmd.com/heart-disease/cardiac-enzyme-studies. http://www.essortment.com/family/cardiacenzymes_svmp.htm Heart Disease and Stress Tests http://www.webmd.com/heart-disease/guide/stress-test--(dupe) Thrombolytic Therapy. vascularweb.org http://www.vascularweb.org/patients/NorthPoint/Thrombolytic_Therapy.html