CardiAssess
Leading the way in Diagnosis, Treatment, and Management
of Cardiovascular Disease and Heart Failure
Download CardiAssess Brochure (pdf)
Obtain Patient Risk Profiles
In order to appropriately assess a patient's risk factors that are, in turn, related closely to adverse patient outcomes, the patient must be stressed (normally by mild to moderate exercise). In other words, a volume load must be placed on the heart in order to assess the cardiopulmonary system's true response to patient activity. It is the same with the assessment of cardiac ischemia using the classical ECG stress test. Some type of exercise modality must be used in order to stress the heart and create an imbalance in myocardial oxygen supply and demand. Classic ECG stress testing uses maximal exercise intensity to obtain the measured data. The CardiAssess system uses "sub-maximal" exercise intensities that reflect those normally experienced by a patient's activities. These data are best reflective of daily living and are used to provide the best cardiopulmonary assessment.
Manage Patient Outcomes In Terms of Changes In Patient Risk
A cardiologist treating a patient with heart disease can now clinically evaluate whether these select risk factors are improving in response to patient therapy, whether it is by medications, medical devices, cardiac rehabilitation or a combination of the above. As a further management tool, trend graphs of individual measurements, and the individual and cumulative Mortality Predictive Index values (y-axis) for successive dates (x-axis) are provided. For the individual measurements, the Mean Value and the Standard Deviation are also provided as horizontal zones. To indicate whether the trend is "good", the areas above and below the standard deviation zone are color-coded. If a large number is "bad", the area above the upper limit of standard deviation is red, and the area below the lower limit of standard deviation is green. If a small number is "bad", the reverse is indicated.
To complete the picture, the CardiAssess System also allows the physician to enter and record the type of therapy being provided to the patient at each successive test date.
Features of the Equipment Utilized
- Small, compact design (<3 lbs) requires little additional space
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Existing stress testing equipment can be utilized, further reducing the acquisition cost
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Software allows testing to be pre-configured for unique patient populations (e.g. pacemaker, heart failure,etc.)
The Operational Technique
- Small, incremental workload protocols are used (e.g. Modified Naughton) to provide a linear work function, which simulates the range of exercise intensity that a patient can be expected to encounter in daily life.
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Oxygen consumption (VO2), carbon dioxide production (VCO2), ventilation (VE) and heart rate (HR) are measured each time the patient breathes.
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During testing, the technician is presented with information in real-time to ascertain when to terminate the test before the patient becomes uncomfortable.
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The "endpoints" of the test are based on linear regression analysis of variable combinations, so the requirement for achievement of maximal effort by the patient is avoided.
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All measured and translated variables are completely substantiated in the scientific literature.
Scientific References
The CardiAssess System uses the following references to calculate the patient risk profiles:
1. Chronotropic Response Index (CRI) -Assessment of Pacemaker Chronotropic Response: Implementation of the Wilkoff Mathematical Model, R. A. Freedman, D. Hopper, J. Mah, J. Hummel and B. Wilkoff. 2001, PACE, Vol 24, 1748-1754.
and
Usefulness of Impaired Chronotropic Response to Exercise as a Predictor of Mortality, Independent of the Severity of Coronary Artery Disease. T. Dresing, E.H. Blackstone, F. J. Pashkow, C.E. Snader, T.H. Marwick, and M.S. Lauer. Am J. Cardiol. 2000,86: 602-609.
2. Peak Oxygen Pulse (VO2/HR) - J. Laukkanen, J.T.T. Salonen, et al. Association of Maximal Oxygen Pulse during Exercise Stress Test with the Risk of Cardiovascular and Overall Mortality. J. Amer. College Cardiol. 2002;39 (5):Abst #3832.
3. Oxygen Uptake Efficiency Slope (VO2/log VE) - T. McRae, III, James Young, Michael Lauer, et. al. Oxygen Uptake Efficiency Slope as a Predictor of Mortality in Chronic Heart Failure. J. Am. College Cardiol., Vol. 39 (5), 2002, 183A.
4. Heart Rate Recovery (HRR, or the slope of HR/time after 1 minute of recovery after termination of exercise). Heart Rate Recovery Immediately After Treadmill Exercise and Left Ventricular Systolic Dysfunction as Predictors of Mortality. J. Watanabe, M. Thamilarasan, E. Blackstone, J. Thomas, M. Lauer. Circulation, 2001; 104, 1911-1916.
5. Ventilatory Efficiency Slope (VE/VCO2) -Ponikowski, P., Darrel, P.F. et al. Enhanced Ventilatory Response to Exercise in Patients With Chronic Heart Failure and Preserved Exercise Tolerance. Circulation. Vol. 103,2001,967-972.