Cardiopulmonary Stress Test (CPX)

CPX is a diagnostic test that analyzes the responses and the cooperation of the cardiorespiratory system, the circulatory system and the metabolic pathways during continuously increasing muscular effort (exercising).  Gas exchange is measured as you breath into a mouthpiece during exercise.  It indicates the maximum amount of oxygen (VO2max) the heart can provide to the working muscles during sustained exercise. 

CPX testing identifies:

• Exercise Capacity
• Lung disorders
• Obstructive or restrictive lung disorders
• Pulmonary hypertension
• Diffusion disorders
• Possible exercise-induced asthma
• Unexplained shortness of breath
• Heart disorders
• Coronary Artery Disease
• Congestive Heart Failure
• Valvular Heart disease
• Congenital Heart Defects
• Identify patients for Heart Transplantation

How to prepare for CPX test?

• CPX test is an exercising test so dress in cool and comfortable clothes with walking or running shoes. You may want to wear a front-buttoning, short-sleeved shirt.
• Eat a light meal approximately 2 hours before you come for the test.
• Withhold all caffeinated beverages, decaffeinated coffee, colas, teas, and chocolate for at least 12 hours prior to your test.
• Take your medications, as per your routine, on the day of the test, unless otherwise instructed.
• Do not apply lotions or powders to the chest.
• Avoid heavy activity on the day of the test.

What Happens during the stress test?

• You will be given an explanation of the test and asked to sign an informed consent giving permisssion to do the test.
• The CPX test has three parts:
  1.  The Pulmonary Function Test
  - This evaluates how well you can move air  in and out of the lungs.  It includes 3 separate breathing exercises that are performed by inhaling and exhaling through a mouthpiece.
  2.  The Exercise Test
  The exercise test includes treadmill walking while you are closely monitored by an exercise physiologist.  If you are not familiar with walking on a treadmill, time for practice and adjustment will be provided. The exercising protocol will be a ramp protocol (speed & incline are increased in small increments), individually selected to yield your maximum effort.  The treadmill test typically lasts for 8-12 minutes. 
• Electrodes will be placed on the chest for an ECG which will continuously monitor your  heart rhythm during exercise.
• Clipped to your fingertip will be a pulse oximeter which indicates your blood oxygenation  level.
• Blood pressure measurements will be taken at rest, during and post exercise
• You will breathe only through your mouth into a soft, rubber mouthpiece.  A padded nose  clip will be placed over your nose to block air coming though your nostrils.
• Since you will be breathing through a mouthpiece, you will communicate with the exercise  physiologist with hand signals that will be arranged before the test so you can report any  symptoms such as chest pain, shortness of breath, or fatigue
• The exercise ends when you signal to stop or enough information is obtained from your  effort to complete the test. 
• A recovery period of slow walking will be done before the treadmill is stopped.  If possible,  you should keep breathing through the mouthpiece for at least two minutes in recovery, so  that post exercise measurements can also be taken.
  3.  Post Exercise Breathing Test
   You will repeat one of the resting breathing tests at 5, 10 & 15 minute post exercise, so that  comparisons can be made between before and after exercise.
   
  Please allow approximately 2 hours for the entire test to be completed.  Final interpretation of your test results will be completed by a cardiologist specialized in Cardiopulmonary stress testing interpretation. You will receive notification of your results within 7-10 days.
  If  your doctor ordered a combination of  Nuclear Cardiac Stress Testing with the CPX, please refer to the Guidelines for “ Nuclear Cardiac Stress Testing” for further information and preparation for the nuclear portion of the test.

Ver. 12