Vicor’s PD2i^® Nonlinear Algorithm—A Revolutionary New Vital Sign

Vicor’s Point Correlation Dimension (PD2i^®) nonlinear algorithm is at the heart of Vicor Technologies’ first three diagnostic products: the PD2i Analyzer™, PD2i CA™, and PD2i-VS™.

Decoding The Interaction of Brain and Heart

We know intuitively that the brain influences the heart. Our hearts race in concert with emotional highs and lows; our language is littered with phrases like “scared to death” and “dying of a broken heart.” And many studies describe increased mortality among depressed or emotionally stressed patients.

Vicor has taken this understanding a step further. Through years of research and experimentation, Vicor Technologies’ Chief Scientist Dr. James Skinner was able to determine that while cardiac arrests occur in the heart, they are initiated by the brain. Dr. Skinner developed the PD2i^® nonlinear algorithm, which examines a sequence of heartbeats to detect the subtle tell-tale patterns which reveal whether the brain’s interaction with the heart is healthy, or instead puts the patient at high risk of sudden cardiac death.

Conventional diagnostics which only evaluate the heart are of limited use in predicting sudden cardiac death. Further, current implantable cardioverter-defibrillator (ICD) implantation guidelines are inadequate and lead to implantations in many people who don't need them; studies show that, at present, twenty ICDs must be implanted to save a single life. Even worse, almost eighty percent of those who do die from sudden cardiac death would not even qualify for implantation under current criteria. Clearly, a more predictive diagnostic is long overdue.

Vicor’s PD2i test may be that diagnostic.

A case in point: Both patients below meet current implantation guidelines. But which one will die without an ICD?

The EKG for Patient 032 (above left) is typical by current interpretations. Conversely, the EKG for Patient 160 (above right) is grossly abnormal by current interpretations. Relying on the above tracings, a physician might well recommend “watchful waiting” for Patient 032 and ICD implantation for Patient 160.

In contrast, the PD2i test able to correctly indicate both Patient 032's imminent sudden cardiac death and Patient 160's lack of risk:

Unlike the EKGs, if confirmed with clinical testing, PD2i testing would predict that Patient 032 was in urgent need of an ICD, and that Patient 160 did not need intervention.

In summary, the PD2i^® nonlinear algorithm, as shown by these examples, should reduce both false positives and false negatives, indications for who does and who does not need an ICD.

Unprecedented Predictive Potential

Vicor has published clinical trial data using the PD2i^® nonlinear algorithm as a predictor of sudden cardiac death, showing it to be highly accurate, with a sensitivity approaching 100% and a specificity of ~86%. All that is required to conduct the analysis is an EKG of a thousand heartbeats (requiring less than twenty minutes.) The PD2i^® nonlinear algorithm typically uses recordings made at rest and does not require stress-testing or any active participation from the patient. The PD2i test is relatively impervious to data non-stationarities and artifacts, setting it apart from other measures, and its sensitivity is unparalleled. (This study has not been reviewed by the Food and Drug Administration

Current Implementations of the PD2i^® Nonlinear Algorithm

FDA marketing clearance for the the first device based on this technology, the PD2i Analyzer™, was received December 29, 2008. The PD2i Analyzer™ measures heartrate variability in patients at rest and in response to paced respiration and controlled exercise, and is expected to be capable of identifying Autonomic Nervous System Dysfunction earlier than conventional means.

Within the next year, Vicor Technologies expects to have launched two additional products: the PD2i-VS™, which facilitates triage of seriously injured trauma patients in combat and emergency care environments, and the PD2i CA™, which risk-stratifies cardiac arrest and sudden cardiac death.

An Advance over Conventional Diagnostics

Vicor’s PD2i tests offer several potential advantages over other measures. They:

• are more predictive than competing tests
• are non-invasive
• may be performed by a nurse or technician
• are done at rest
• use inexpensive, non-proprietary EKG electrodes
• provide results in less than twenty minutes
• are easy to use; yield a simple binary result
• are compact and portable
• are forgiving of data issues plaguing other diagnostics; not derailed by irregular or ectopic beats
• can be performed on patients taking beta-blockers
• have low up-front cost and low cost per test

Learn More About Vicor’s PD2i Technology

To find out more about Vicor’s PD2i technology, call Vicor at (877) 528-PD2i (7324), or refer to our Contact page.