CARDIOPULMONARY EXERCISE TEST

By: ASER MOHAMED KAMAL

The Cardiopulmonary Exercise Test is a highly sensitive, non-invasive stress test. It is considered a stress test because the exercise stresses your body’s systems by making them work faster and harder. A disease or condition that affects the heart, lungs or muscles will limit how much faster and harder these systems can work. A CPET assesses how well the heart, lungs, and muscles are working individually, and how these systems are working in unison. heart and lungs work together to deliver oxygen to muscles, where it is used to make energy, and to remove carbon dioxide from body.

The full cardiopulmonary system is assessed during a CPET by measuring the amount of oxygen body is using, the amount of carbon dioxide it is producing, breathing pattern, and electrocardiogram (EKG).

the CPET is also used to monitor changes in disease condition, the effect of certain medications on body , and if medical therapy is improving patient condition.

What conditions can be detected by the

Cardiopulmonary Exercise Test?

Heart Failure – The inability of the heart to pump enough blood to meet the needs of the body’s other organs .

Myocardial Ischemia – Reduced blood flow to one or more parts of the heart due to blockage or spasm.

Cardiac valve dysfunction – Valves do not open and close properly to contain blood inside the chambers of the heart.

Chronotropic incompetence – Inability of the heart to increase speed of contraction (heart rate) due to medication or intrinsic factors.

Pulmonary ventilation disorder – Lungs are not able to take in enough air to meet the body’s demands (ex: asthma, COPD, emphysema).

Pulmonary circulation disorder – Inability of the body to pull oxygen from the lungs into the bloodstream.

Muscle metabolic disorders – Inability of the muscle cells to use oxygen from the bloodstream to produce energy for the working muscle tissues.

Deconditioning – Poor cardiovascular fitness that can be improved with exercise.

Other Fields of CPET:Pulmonary …….

Cardiology ………

Sports medicine

Occupational medicine

Intensive care

Rehabilitation

►physical performance►exercise prescription ►quality of trainning

►occupational exercise tolerance (Air traveler, diving, fireman)

►Risk assessment prior to surgery ►Nutrition

►design of Reh. programs►assessed the improvement

Preliminary evaluation of the subject HISTORY TAKING : tobacco use, medications, tolerance to normal physical activity , any distress symptoms and contraindication illness. PHYSICAL EXAMINATION : height, weight and assessment of the subjects heart, lung , peripheral pulses and blood pressure. ECG ROUTINE PULMONARY FUNCTION TESTS.( lung volumes, simple spirometry , diffusing capacity and arterial blood gases ).OBTAIN INFORMED CONSENT

How should I prepare for Cardiopulmonary Exercise Test?

1- be sure to wear comfortable clothing

2-  proper footwear

3-  Do not eat or drink (except water) for 3 hours before your test

4- Exercise or physical labor should be avoided for 24 hours before test.

5- Bring a list of current medications

6-Tell doctor if any joint problems .

7-caffeine for 12 to 24 hours and smoking for several hours before the stress test

8-Give your best effort and exercise for as long and hard as possible.

9-Let the technician know if you have discomfort or pain at any point during the test.

patients

Preparation of the lab Should be air – conditioned and temp. regulated to be

comfortable for an exercising subject. the subjects view should not be full of medical equipments esp. the invasive one.

The equipments should be organized and laid out in preparation.

Resuscitation equipments should be available and on hands. the responsible personnel should be tested and certified for

performing CPR

Before exercise begins,

subject will be asked to

perform lung tests.

warm up

The test will continue

until subject are giving his

maximum effort and

can no longer

continue.

cool down while

continues monitoring vital signs.

repeat one of the lung tests to

determine if exercise

changes the way of lungs

function.

The actual time it takes to perform the test will be between 15 and 25 minutes

•Face mask:• This monitors the oxygen used, carbon dioxide produced, and the breathing pattern. The mask is placed over the mouth and nose .

•Electrocardiogram (EKG):• Ten stickers will be placed on chest with monitoring wires attached. This is used to monitor your heart rate and rhythm.

•Blood pressure cuff: •Your blood pressure will be taken multiple times during the test.

•Pulse oximeter:• This is a small device that slides over your finger and uses a light to measure the percentage of blood cells covered with oxygen

How is a Cardiopulmonary Exercise Test performed?

During the test we Measure • Pulmonary parameters: RR – minute

ventilation- end –tidal oxygen and carbon dioxide- Oxygen consumption and Co2 production

• Cardiovascular parameters: Heart rate, blood pressure, ECG

Guidelines for Exercise Testing Types of Tests

Maximal vs. Submaximal Choice depends on clients age,risk stratification, reasons for

doing the test Modes of Testing:

Treadmill Bicycle Ergometer Arm Ergometer

Maximal Exercise Test Protocols: Treadmill Protocols:

Bruce, Modified Bruce, Balke, Naughton, Wilson, Kattus, etc. Bicycle Ergometer Protocols:

Astrand, Fox

Submaximal Exercise Test Protocols: MultistageTreadmill: uses max. protocol with selected HR

endpoint (usually 80-90% HRMx) Single Stage Treadmill: uses constant speed for 3-6

minutes Bicycle Ergometer Protocols:

YMCA, Astrand-Ryhming, Fox, Lifecycle, AirDyne Other Protocols: Step test, Stairmaster, Rower Ergometer

How do you know when you reach the MAX?

The graded exercise test measures maximum aerobic capacity (VO2max) when the oxygen uptake plateaus….does not increase any more than 150 ml/min with a further increase in work load.

Considerations for Max testing... Health status screening essential Fitness level important in selection of protocol Accurate measurements of HR, BP, etc. very important. Warming up to familiarize with equipment Cool-down procedures, with continual monitoring very

important Continuously monitor physical appearance and

symptoms. Discontinue test when criteria is met for MAX test Or if

any indications for stopping test occur.

Bruce Treadmill Test:a)  evaluates a patient's overall fitness and cardiovascular conditionb) The athlete warms up for 10 minutesc) The assistant sets the treadmill up with a speed of 2.74 km/hr. and an

incline of 10%  (Stage 1)d) The assistant gives the command “GO”, starts the stopwatch and the

athlete commences the teste) The assistant, at the appropriate times during the test, adjusts the

treadmill's speed and slope as per the table (e.g. after 3 minutes the speed is adjusted to 4.02 km/hr and the slope to 12% and so on)

f) The assistant stops the stopwatch when the athlete is unable to continue and records the time (T).

Stage Time (min) km/hr Incline

1 0 2.74 10%

2 3 4.02 12%

3 6 5.47 14%

4 9 6.76 16%

5 12 8.05 18%

6 15 8.85 20%

7 18 9.65 22%

8 21 10.46 24%

9 24 11.26 26%

10 27 12.07 28%

Active and sedentary men

VO2 max = 14.8 - (1.379 × T) + (0.451 × T²) - (0.012 × T³)

Active and sedentary women

VO2 max = 4.38 × T - 3.9

Modified Bruce Protocol

I. Because the Bruce Protocol requires that patients be somewhat physically fit, a modified Bruce Protocol exists for patients who are obese or elderly. This test is shorter and easier on the heart. The modified Bruce Protocol starts the treadmill at 1.7 mph at no incline. After three minutes, the clinician increases the incline to 5 percent. For the final three minutes, the clinician increases the speed to 2.74 mph and the incline to 10 percent. The test can be stopped at any time.

 Cardio Light Stress Test:I.  is designed to take an in-depth reading of your heart rate to determine

problems associated with angina, or chest pain, coronary disease or arterial blockages. Because of the test's accuracy, it can tell if your heart is working at normal capacity or if it is working harder than it should be.

II.  The patient is then asked to walk, jog or run for a sustained time. A stress test measures the heart's ability under stress, such as when exercising.

III. A doctor may perform a light cardio stress test for patients who are at higher risk of heart problems, such as cardiac arrest, or for elderly patients.

What Are the Different Types of Stress Tests?

Some

Heart disease is the leading cause of death in the United States, with coronary artery disease being the common most type, according to the Centers for Disease Control and Prevention. A stress test can show whether a patient does or does not have heart disease. A stress test also determines the amount of stress a heart can handle before developing a reduced amount of blood flow to the heart muscle. The types of tests most commonly performed include exercise stress tests, adenosine stress tests, nuclear stress tests and stress echocardiograms

Heart Rate During a Stress Test

A stress test can help determine your maximum capacity for exercise

Exercise Stress TestThe Harvard Medical School states that an exercise stress test makes patients work at a high level of exercise, causing their heart to work harder to see if it is receiving an adequate amount of blood flow and oxygen. According to the Harvard Medical School, the most commonly referred patients to exercise stress testing include those who appear to have known coronary artery disease and who have symptoms such as chest pain, shortness of breath, light-headedness, etc.

An exercise stress test can assist in diagnosing heart disease or assessing the effectiveness of heart disease treatment, such as prescribed medication. Doctors can also write an appropriate exercise prescription for patients from the results of their exercise stress test.

Adenosine Stress TestPatients who cannot exercise must undergo a pharmacological stress test consisting of medication known as adenosine. The Cleveland Clinic states that adenosine works by dilating the blood vessels leading to the heart, which increases blood flow, thus stimulating exercise. Adenosine essentially mimics exercise immediately after it's taken. During "exercise," a small amount of a radioactive tracer is injected into the patient's vein. A special camera then detects the radiation released by the tracer to produce images of the heart on a monitor, according to the Cleveland Clinic. 

This test allows doctors to determine how adequately the heart distributes blood flow during stress versus at rest and in diagnosing coronary artery disease

Nuclear Stress TestA nuclear stress test measures blood flow to the heart muscle, according to the Mayo Clinic. The Mayo Clinic states that a nuclear stress test involves injecting a patient with a medication that increases the blood flow to his heart muscle, essentially stimulating exercise. A special camera produces clear pictures of the heart tissue on a monitor. These images show areas of low blood flow and areas of damaged heart muscle. The images of the heart are taken during the stress phase and during the rest phase. 

A nuclear stress test shows how well the heart works during stress (exercise) and at rest. Nuclear stress tests help doctors to diagnose coronary artery disease and heart enlargement, so doctors can devise a proper treatment plan.

Stress EchocardiogramMedline Plus states that a stress echocardiogram determines how well the heart muscle responds to stress. A stress echocardiogram uses ultrasound imaging to show whether the heart is receiving enough blood flow and oxygen while under stress. Doctors can discover and potentially treat any blockage or disease from the results of a stress echocardiogram.

Medline Plus states that doctors typically refer patients who have symptoms of recent chest pain, recently had a heart attack, those at high risk for heart disease and those who have valve problems to have a stress echocardiogram.

Test Heart Rate

As you complete your stress test by walking at various speeds as indicated by the technician throughout your test, your heart rate will be monitored through the use of electrodes. The actual rate of your heart will depend on the physical condition you are in and if you have any underlying health problems. A stress test can also help determine the maximum heart rate your body can achieve during exercise. After your stress test, your doctor will discuss with you your target heart rate and the amount of exercise you should be engaging in.

Considerations

Remember that average heart rates -- both resting and maximum -- are just averages. Your heart rate may not fall in the normal range, which does not necessarily mean you have reason for concern. For example, if you are an athlete, your resting heart rate will likely be slower than average. Diabetes, high blood pressure and certain medications increase your heart rate. Ask your doctor about any questions or concerns you have.

The Balke Treadmill Protocol

The Balke treadmill protocol can be used to estimate cardiovascular condition and endurance by measuring maximum oxygen uptake, known as V02max. You can undergo this fitness test at a slow pace, making it suitable for cardiac patients as well as healthy people.

Balke 15 minute runThis 15 minute run test, designed by Bruno Balke, is one of many field tests designed to measure aerobic fitness. This test has formula to predict VO2max from the run distance.aim: a running test to measure aerobic fitness (the ability of the body to utilize oxygen to power it while running).equipment required: flat oval or running track, marking cones, recording sheets, stop watch.procedure: Place markers at set intervals around the track to aid in measuring the completed distance. Participants run for 15 minutes, and the distance covered is recorded. Walking is allowed, though the participants must be encouraged to push themselves as hard as they can

Required ResourcesTo undertake this test you will require: Treadmill Stopwatch Assistant

What the Test MeasuresVO2max provides a measure of how well your circulatory and respiratory systems can supply oxygen and nutrients to your body during exercise. When you exercise, your heart works harder to deliver nutrients and oxygen, which are carried by the blood to your muscles. Also, your breathing rate increases to increase your oxygen uptake in the lungs. The higher your VO2max, the better your oxygen and nutrient delivery to your muscles, and the harder you can exercise

How to TestYou can easily do the Balke test yourself. You need a treadmill and timer. You can also use a monitor to track your heart rate during the test if you desire. Start with a 10-minute warm-up on the treadmill or another exercise device if you prefer.

The Balke ProtocolStart the timer when you are ready to begin the test. Use a constant speed of 3.3 mph if you are a man and 3.0 mph if you are a woman. Begin the test by setting the incline at 0 percent. Increase the incline 2 percent after 1 minute and 1 percent thereafter every minute if you are a man and 2.5 percent every 3 minutes if you are a woman. Continue doing this as long as you can. The idea is to keep up the pace and increase the incline until you are exhausted and cannot continue. It is important you record your quit time since it is used for the VO2max calculations.

Analyzing VO2maxAfter the test, evaluate your maximum oxygen uptake with a formula. For men the calculation is 1.444 x time + 14.99, and for women the calculation is 1.38 x time + 5.22. Use whole minutes and fractions in the formula, for example, 15 minutes 15 seconds would be 15.25. 

Repeat the test every few weeks or months of training. You should improve your VO2max as you train because your body adjusts to the training and improves your maximum oxygen uptake.

Target GroupThis test is suitable for active and sedentary individuals but not for those where the test would be contraindicated.ReliabilityTest reliability refers to the degree to which a test is consistent and stable in measuring what it is intended to measure. Reliability will depend upon how strict the test is conducted and the individual's level of motivation to perform the test.

Advantages•Minimal equipment required•Simple to set up and conductDisadvantages•Specialist equipment required - treadmill•Assistant required to administer the test

Ross Test Protocol

Before your test begins, the tester will likely record your resting heart rate and blood pressure, to get your baseline values. The tester then places electrodes on your chest, torso and shoulders; it is likely that you will wear an oxygen mask to monitor your respiratory behavior. The electrodes are used to record the electrical activity of your heart. The treadmill will remain at 3.4 mph throughout the duration of the test. It will begin with zero incline but will increase, every 3 minutes, by 4 percent for men and 3 percent for women. If you are physically able, your test will last for five stages -- a total of 15 minutes.

Disadvantage Advantage

More cooperation from patients

Similar to walking

Noisy Setting of speed and graded for all size

Patient hold handrail ----------------------

Patient can not stop in emergency case

---------------------

TREADMILL

Other VO2 max criteria: Failure of the heart rate in increase with increases in

exercise intensity venous lactate concentration exceeding 8mM/L RQ (respiratory exchange ratio) greater than 1.15 RPE greater than 17 (using the original Borg scale of 6-

20)

Normal Blood Pressure Increase During Treadmill Testsi. Blood pressure is a measurement of the force in which blood

hits artery walls as it pumps through body. A normal blood pressure reading is less than 120/80, with the 120 referring to systolic or beat pressure, and the 80 referring to diastolic, or the pressure between heartbeats.

ii. Your doctor uses blood pressure readings obtained from a treadmill test to find evidence of coronary artery blockage. Under normal circumstances, you can expect systolic blood pressure to increase to about 200 at the peak of the test and diastolic blood pressure to remain steady or fall only slightly. Heart disease is a likely if your systolic pressure does not rise above 120, if it falls, or if your diastolic pressure rises above 90 to 100.

Contraindication:

1. severe lung disease2. unstable angina3. uncontrolled high blood pressure4. myocarditis 5. severe anemia