Technological innovation will drive Holter monitor sales. (ambulatory electrocardiograph monitors)

The ambulatory electrocardiograph monitor market is continuing to grow steadily due to the development of more sophisticated and cost-effective systems from established and newer players.

Ambulatory ECG or Holter monitors record a patient's cardiac rhythm for 24 hours or longer. Since its introduction more than 20 years ago, Holter monitoring has been widely used for a number of clinical purposes: to correlate patients' arrhythmias with their symptoms, to assist in making a prognosis, to guide antiarrhythmic therapy and to detect and provide therapy for myocardial ischemia.

The applications for Holter monitoring have recently become more procedure-specific. Such applications include: follow-up for heart attack patients; measuring heart rate variability; identifying silent ischemia/ST segment analysis; identifying patients at risk for sudden death; and detecting implantable pacemaker malfunctions.

Features of the high-end and mid-end systems, which account for the majority of sales, include improved computer and networking power; multi-channel arrhythmia and ST segment analysis; heart rate variability; pacemaker analysis; late potential assessment; and pediatric analysis capability.

Some suppliers, such as Advanced Medical Products, Liverpool, N.Y., and Stuart Medical, Owings Mills, Md., have launched combination Holter and ambulatory blood pressure monitoring systems.

The potential market for such products is about $30 million annually, according to AMP, based on its calculations of an $8 million annual blood pressure product market and $50 million annual office-based Holter market. Other suppliers say the physicians' office Holter market is much smaller.

Another supplier, Ralin Medical Inc., Des Plaines, introduced at the American College of Cardiology meeting in April a cardiac event recorder that can be worn on the wrist. Patients activate the WristRecorder by touching electrodes when they feel symptoms. After the patient records a cardiac event, he or …