New algorithms may help predict risk of sudden cardiac death
16 November 2005
Dallas, Texas. GE Healthcare has announced that the company has developed
two new algorithms that may help physicians predict whether a patient is at
risk for sudden cardiac death (SCD). The two new breakthrough algorithms —
the Marquette T-Wave Alternans algorithm and the Marquette Heart Rate
Turbulence algorithm — when inputted with ambulatory electrocardiography
(ECG) data have been shown to help predict if a person is at risk for SCD.
For the first time, the algorithms can be used in combination with
technology that is portable, making diagnostic tests available to patients
anytime, anywhere. The announcement was made at the annual meeting of the
AHA in Dallas.
SCD, or death resulting from an abrupt increase to a heart rate that is too
fast, accounts for approximately 930 deaths in the United States each day,
according to the American Heart Association (AHA).
"SCD is a major public health problem in the United States," said Matthias
Weber, vice president of GE Healthcare's Diagnostic Cardiology business. "As
such, one of the most compelling challenges facing physicians today is the
identification of which patients are at the highest risk for SCD. It is GE's
hope that the wealth of detailed, accurate cardiac information provided by
these algorithms will help physicians better understand which patients are
at highest risk for SCD and enable them to prescribe proactive treatments
that can help reduce these deaths."
Ambulatory ECG data, also known as Holter monitoring, is a technique
commonly used by physicians to investigate whether a patient's symptoms,
such as fainting, dizziness, or palpitations, are caused by a heartbeat that
is too slow, too fast, or very irregular. Because GE's Holter system is
portable it enables physicians to monitor a patient's heart rate information
during their normal everyday activities.
In conjunction with GE's Holter monitoring system, the T-Wave Alternans
algorithm precisely detects fluctuations in the ECG waveform, identifying a
pattern variation that can indicate SCD risk. The presence of T-wave
alternans may help physicians predict which patients are at risk for SCD,
enabling them to make earlier treatment decisions, such as whether a
defibrillator should be implanted. GE's Heart Rate Turbulence algorithm
measures and compares the heart rate before and after premature beats,
providing comparison data used to measure how the patient's heart and
autonomic nervous system work together, which can determine cardiac health.
"Used together, these algorithms interpret complex cardiac rhythms that
provide a more accurate, advanced way to determine which patients are at
risk for SCD and would benefit most from a implantable defibrillator," said
Dr. Richard L. Verrier, associate professor of Medicine, Harvard Medical
School and Beth Israel Deaconess Medical Center. "This noninvasive and
portable method for diagnosing patients should significantly benefit those
patients who may be at higher risk for SCD or help in prescribing the most
appropriate therapies to prevent SCD."
GE's algorithms can be applied to the ECG of patients who have had heart
attacks to help determine their relative risk of sudden cardiac death, and
aid the physician in determining if they are in need of an implantable
cardiac defibrillator. In patients who have not had cardiac episodes, the
algorithms can be used to help evaluate electrical instability in the heart.