Sudden cardiac death

has developed two new algorithms that, when used together, may help doctors predict whether a patient is at risk for sudden cardiac death (SCD).

And, for the first time, the algorithms can be used in combination with technology that is portable, making diagnostic tests available to patients anytime and anywhere.

SCD, or death resulting from an abrupt increase to a heart rate that is too fast, accounts for approximately 930 deaths in the US each day, according to the American Heart Association (AHA).

GE’s two new 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.

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.