Cardiovascular Laboratory Values and Diagnostic Study’s

By: Lauren M. Boche`

Laboratory Test

• CBC

• Differential count

• Absolute Neutrophil Count (ANC)

• Bleeding Screen

• Blood Typing

• ESR

• ECG

• Telemetry

• Holter Monitor

• Stress Test

• Chest radiograph

• Cardiac fluoroscopy

• Cardiac Catheterization

• CT/MRI

Diagnostic Test

Complete Blood Count

• A complete blood count is a count of the total number of cells in a given amount of blood, including the red and white blood cells; often referred to as a CBC, it is one of the most common tests done to check for abnormalities of the blood

CBCHemoglobin:Males:14-18 g/dlFemales: 12-16 g/dl Measures oxygen carrying capacity of

blood.Low: hemorrhage, anemiaHigh: polycythemia (abnormal increase

of RBC’s)

Red blood cell: 4-6 million/mm3 Measures oxygen-carrying capacity of

bloodLow: hemorrhage, anemiaHigh: polycythemia, heart disease,pulmonary disease

CBC

Hematocrit:

Males: 42%-52%

Females: 37%-47%

Measures relative volume of cells and plasma in

Low: hemorrhage, anemia

High: polycythemia, dehydration

WBC with DifferentialNeutrophils: 54%-62%• Increase in bacterial infections, hemorrhage, diabetic

acidosisLymphocytes: 25%-30%• Viral and bacterial infection, acute and chronic

lymphocytic leukemia, antigen reactionEosinophils: 1%-3% • Increase in parasitic and allergic conditions, blood

dyscrasias, pernicious anemiaBasophils: 1%• Increase in types of blood dyscrasias (unspecified

disorders)Monocytes: 0%-9% • Hodgkin’s disease, lipid storage disease, recovery from

severe infections, monocytic leukemiaWBC: 5,000-10,000Collagen disorder, rheumatic fever, and pancreatits,

trauma, leukemia, chemotheraphy, aplastic anemia.

Absolute Neutrophil Count (ANC)

• Absolute neutrophil count (ANC) is a measure of the number of neutrophil granulocytes present in the blood. Neutrophils are a type of white blood cell that fights against infection.

• A deficiency of neutrophils, known as neutropeia, may increase chances of infection.

Absolute Neutrophil Count (ANC)

• Normal value:

• Greater than 1500

• Less than 1000 Patient at increased risk for infection.

Coagulation Screening

• Prothrombin Time

• Partial thromboplastin Time

• Platelets

• Bleeding time

• International Normalized Ratio (INR)

Coagulation Screening

Prothrombin time: 1-18 sec

Is a performance indicator measuring the efficacy of both the "intrinsic" and the common

coagulation pathways. Apart from detecting abnormalities in blood clotting, it is also used to

monitor the treatment effects with heparin, a major anticoagulant.

Prolonged in liver disease, impaired Vitamin K production, surgical trauma with blood loss

Coagulation Screening

Partial thromboplastin Time• 60 – 70 seconds

Measures intrinsic clotting of blood, congenital clotting disorders.

Prolonged in hemophilia A,B, and C and Von Willebrand’s disease.

Von Willebrand disease is caused by a deficiency of von Willebrand factor. Von Willebrand factor helps platelets

to clump together and stick to the blood vessel wall, which is necessary for normal blood clotting

• Formation of fibrin and trapping of red blood cells to form a clot.

Coagulation Screening

Platelets

140,000-340,000/mL

• Measures clotting potential Increased in polycythemia, leukemia, severe

hemorrhage; decreased in thrombocytopenia purpura (responsible for

leaving large multimers of von Willebrand Factor).

Coagulation Screening

Bleeding time

1-6 min

• Measures quality of platelets Prolonged in thrombocytopenia (low platelets)

Coagulation screening

• International Normalized Ratio (INR)– The prothrombin time (PT) and its derived

measures of prothrombin ratio (PR) and international normalized ratio (INR) are measures of the extrinsic pathway of coagulation. They are used to determine the clotting tendency of blood.

– The normal range for the INR is 0.8-1.2.

Blood types

• A persons blood type is genetically determined and is inherited from his or her parents. Blood types are determined by the presence or absence of specific antigens on the outer surface of the RBCs.

• Every persons blood is one of the following blood types in the ABO system of typing: type A, type B, type AB, or type O.

• Blood typing is done mainly for Blood transfusion.

Blood typing

Type O blood is the universal donor blood.

Type AB blood is the universal recipient.

Erythrocyte sedimentation rate(ESR)

• Rate at which RBC’s Settle out of a tube of unclotted blood in 1 hour.

• Used to monitor or rule out inflammatory conditions of the heart. The sedimentation rate is elevated with MI and bacterial endocarditis and decreased when healing begins. The level of the ESR also indicates the extent of inflammation and infection in rheumatic fever.

ESR

Male: 0-15 mm/hr

Female: 0-20 mm/hr

Electrocardiogram

• An electrocardiogram (ECG or EKG) is a graphic produced by an electrocardiograph, which records the electrical activity of the heart over time. Analysis of the various waves and normal vectors of depolarization and repolarization yields important diagnostic information.– It is the standard for the diagnosis of cardiac arrhythmias. – It guides therapy and risk stratification for patients with

suspected acute Myocardial Infarction. – It helps detect electrolyte disturbances (e.g. hyperkalemia

(increased potassium) and hypokalemia (decreased potassium). – It allows for the detection of conduction abnormalities (e.g. right

and left bundle branch block) – It is used as a screening tool for ischemic heart disease during a

cardiac stress test.

Electrocardiogram (ECG)

Normal Sinus Rhythm

Telemetry

• Telemetry also is used for patients who are at risk of abnormal heart activity, generally in a coronary care unit.

• Such patients are outfitted with measuring, recording and transmitting devices.

• A data log can be useful in diagnosis of the patient's condition by doctors.

• An alerting function can summon nurses if the patient is suffering from an acute or dangerous condition.

Telemetry monitors

Holter Monitor

• A Holter monitor (also called an ambulatory electrocardiography device), named after its inventor, Dr. Norman J. Holter, is a portable device for continuously monitoring the electrical activity of the heart for 24 hours or more.

• Its extended recording period is useful for observing occasional cardiac arrhythmias that would be difficult to identify in a shorter period of time.

• For patients with more transient symptoms, a Cardiac Even Monitor which can be worn for a month or more can be used.

Holter Monitor

Cardiac Stress Test

• A cardiac stress test is a medical test performed to evaluate arterial blood flow to the myocardium during physical exercise, compared to blood flow while at rest.

• As an exercise test, the results can also reflect overall physical fitness. These tests do not assess emotional stress, or other connotations of the term stress.

• If radioactive isotopes are also used (Thallium-201), then it is usually called a nuclear stress test. Given the ability to visualize the relative amounts of radioisotope within different regions of the heart muscle, nuclear stress tests are more accurate in detecting regional relatively normal versus decreased blood flow to cardiac cells.

Stress Test

Chest Radiograph

• Chest radiographs provide visualization of lungs, ribs, clavicles, humeri, scapulae, vertebrae, heart, and major thoracic vessels.

• Gives important information on alteration in size and location of pulmonary structres and blood flow. – Any articles of clothing containg metal or

jewelry must be removed since the metal will produce a shadow on the film.

Chest Radiograph

• Fluoroscopy is an imaging technique commonly used by physicians to obtain real-time images of the internal structures of a patient through the use of a fluoroscope. In its simplest form, a fluoroscope consists of an x-ray source and fluorescent screen between which a patient is placed. However, modern fluoroscopes are equipped with CCD video Camera allowing the images to be played and recorded on a monitor.

Cardiac Fluoroscopy

Cardiac catheterization • Cardiac catheterization (heart cath) is

the insertion of a catheter into a chamber or vessel of the heart. This is done for both investigational and interventional purposes. Coronary catheterization is a subset of this technique, involving the catheterization of the coronary arteries.

• A small puncture is made in a vessel in the groin, the inner bend of the elbow, or neck area (the femoral vessels or the carotid/jugular vessels), then a guidewire is inserted into the incision and threaded through the vessel into the area of the heart that requires treatment, visualized by fluoroscopy or echocardiogram, and a catheter is then threaded over the guidewire. If X-ray fluoroscopy is used, a radiocontrast agent will be administered to the patient during the procedure.

This technique has several goals:

• confirm the presence of a suspected heart ailment.

• quantify the severity of the disease and its effect on the heart

• seek out the cause of a symptom such as SOB or signs of cardiac insufficiency.

• to take tissue samples for biopsy.

• to inject various agents for measuring blood flow in the heart; also to detect and quantify the presence of an intracardiac shunt.

• to inject contrast agents in order to study the shape of the heart vessels and chambers and how they change as the heart beats

Cardiac Catheterization

Computed tomography (CT scan)

• Is a medical imaging method employing tomography where digital geometry processing is used to generate a three-dimensional image of the internals of an object from a large series of two-dimensional x-ray.– CT can also show the

difference between an organ that is ischemic or not.

CT scan

MRI

• Magnetic resonance imaging is a non-invasive method used to render images of the inside of an object. It is primarily used in medical imaging to demonstrate pathological or other physiological alterations of living tissues.

• Certain exams require that a special dye (contrast) be given before the test. The dye is usually given through an intravenous line (IV) in your hand or forearm. The contrast helps the radiologist see certain areas more clearly

MRI

• There are many diagnostic test that can be an effective way of early detection of cardiac problems.

• Getting help when you discover the first signs and symptoms can save your life.