History
Philips, via its acquisition of the former Hewlett-Packard Medical Products Group, has been a pioneer, innovator, and leader in computerized ECG data analysis for over 40 years. Design of specialized algorithms began in the late 1960’s, and accelerated in the 1970’s as Philips enhanced the single lead programs that were the standard at the time. In 1978, Philips introduced its multi-lead, 12-lead analysis program, the first among the major electrocardiography companies.
Philips has been a continuing leader in ECG analysis, with significant innovations and firsts in serial comparison, gender-specific analysis, pediatric analysis, pacemaker detection, sophisticated QT analysis, support of the XML data format, and other areas. In the past, a specialized ECG language - ECG Criteria Language (ECL) - was developed to encourage broader participation and speed development of sophisticated algorithms.
Today, this experience and expertise is reflected in the Philips DXL ECG Algorithm with its industry leading integration of extended leads and expanded analysis capabilities.
Philips DXL Algorithm for Resting ECGs
The Philips DXL Algorithm goes beyond traditional 12-lead interpretation of the resting ECG in two ways. First, it can provide for not only 12-lead interpretation, but also the addition of up to 4 additional leads to provide for a extended interpretations for adult chest pain or routine pediatric ECG analysis. Second, the DXL Algorithm also provides for incremental diagnostic capabilities and advanced STEMI decision support tools not associated with ECG analysis programs of the past. Those capabilities and tools are described further below.
The DXL Algorithm also reflects new recommendations, such as the 2007 AHA/ACCF/HRS recommendations for diagnostic statements1 and the 2009 recommendations for acute ischemia and infarction2. The DXL Algorithm is available on the PageWriter TC Series Cardiographs and the HeartStart MRx Monitor/Defibrillator.
16-Lead ECG Analysis
While the limb leads and chest leads comprise the standard 12-lead ECG, it has long been recognized that additional electrodes can provide information that is poorly or not at all seen on the traditional 12-lead ECG. In addition to the standard 12 leads, the DXL 16-lead Algorithm can incorporate up to four of six additional leads (V3R, V4R, V5R, V7, V8, and V9) to provide an integrated 16-lead analysis, useful for extended interpretations for adult chest pain.
ST Maps
| The 2009 AHA/ACCF/HRS document (2) recommends the display of the spatial orientation of the ST-segment deviations in both frontal and transverse planes. Philips IntelliVue monitors and PageWriter TC Series cardiographs can display patented ST Maps in both planes to provide for rapid visual assessment of the degree of ST abnormalities. |
STEMI-CA for Identification of Culprit Artery
The DXL Algorithm's STEMI-CA criteria can identify the culprit artery or probable anatomical site causing the functional ischemia. STEMI-CA is consistent with the 2009 AHA/ACCF/HRS recommendations.
Critical Values
Critical Values are highly visible independent statements that appear on the display and in ECG reports for the PageWriter TC Series cardiographs and HeartStart MRx Monitor/Defibrillator. These Critical Value statements highlight conditions requiring immediate clinical attention. The Critical Values feature can be used to support Door-to-Balloon and quality initiatives.
Gender-Specific Interpretation
Modern advances have led to better understanding of the physiological differences between men and women - and the differences in ECG. Gender-specific criteria are not new to Philips. They have been incorporated into multi-lead algorithms since 1987 and have been enhanced continually. For example, the DXL Algorithm applies gender, lead, and age limits for improved detection of acute MI based upon the 2009 recommendations.2
Integrated Pediatric Analysis
Philips introduced the industry's first pediatric ECG analysis capabilities in 1982 - and has built upon that experience to deliver an advanced, fully integrated pediatric interpretation. With the DXL Algorithm, the interpretation now can use the availability of additional leads - typically 15 in the pediatric application.
QT Analysis
Because of the relatively recent appreciation of the connection between many medications and the development of Torsade de Pointes, there has been renewed interest in the accurate measurement of the QT interval. Philips ECG algorithms uses an innovative measurement technique to ensure an accurate and reproducible end of T measurement. The same QT measurement technique is used within the resting ECG algorithms and has been further applied for use within Philips IntelliVue monitoring system's ST/AR algorithm and Holter system's Zymed Algorithm.
LeadCheck Quality Assessment
Patented LeadCheck software identifies 19 possible lead reversal and placement errors during ECG acquisition and provides immediate feedback to the user.
Zymed Algorithm for Holter
Philips' powerful Zymed Algorithm for Holter analysis is used to interpret cardiac data acquired from ambulatory subjects over extended periods of time (from 24 hours to 7 days). Introduced in the early 1980s and continually enhanced over the past two decades, the Zymed Algorithm is a leading Holter analysis program worldwide.
1 AHA/ACCF/HRS Recommendations for the Standardization and Interpretaton of the Electrocardiogram, Part II: Electrocardiography Diagnostic Statement List. J Am Coll Cardiology, 2007 49:1128-135.
2 AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram, Part VI: Acute Ischemia/Infarction. Circulation, 2009;100:e262-e270.