Quest Exercise Stress System (Quest), Version 3.52

QUEST is designed to provide ECG information and data to qualified medical personnel for the purpose of assessing the patient’s cardiac response to exercise. It is to be used in hospitals, clinics, or physician offices by a qualified and licensed physician, or by trained staff under the direct supervision of that physician.

Stress-test or exercise electrocardiography is used a) when the diagnosis of coronary artery disease is suspected, b) to determine the physical performance characteristics of a patient, c) for post myocardial infarction assessment, or d) for cardiac rehabilitation. The test involves the recording of the electrocardiogram during dynamic or, occasionally, isometric exercise. Disease assessment is most prominent in adult patients. The diagnostic value of exercise testing primarily concerns either ST segment depression present in myocardial ischemia, or elevation seen in infarcts (in comparison to P-Q segment as the isoelectric line). In addition, it is important to consider the patient’s blood pressure response and physical symptoms.

This instrument is not intended to interpret any exercise test results but is to be used as an aid for the physician to determine normal or abnormal response of the patient to exercise.

QUEST is not intended for long term monitoring of patient ECG signals. Specifically, it does not substitute for recommended cardiac monitoring devices recognized by AAMI EC13, especially in the area of alarms.

This instrument (QUEST) provides a method of collecting a multichannel ECG for dynamic evaluation of exercise performed by the patient. In order to provoke myocardial ischemia, the degree of stress must be sufficient to exceed the critical level of the patient's myocardial oxygen demand. The specificity of ST changes in identification of ischemia increases with the degree , time of onset, and when more than one electrocardiograph lead exhibits the abnormality. These patients can walk on a treadmill in which the speed and elevation can be adjusted (automatically or manually) to suit a variety of graded exercise protocols, or pedal an electronically braked bicycle ergometer. If the test subject is unable to walk, isometric exercise can be performed using a handheld dynamometer, or injecting the patient with heart rate stimulants to stress the myocardial system and then use this instrument's monitoring capability. It is operated from a standing position with design consideration given to ergonomic heights, viewing access of the information display, and control functions. It is cart based, with wheels, to provide easy movement. It can be used in conjunction with echocardiography, nuclear imaging, or pulmonary gas exchange equipment by providing ECG trigger signals andor treadmill speed and grade levels.

This instrument can also serve as an adult resting interpretive electrocardiograph with the addition of Burdick's resting interpretive program.

The QUEST with T-Wave Alternans Option is intended for the measurement of Microvolt T-Wave Alternans" at rest and during ECG stress testing.

The presence of Microvolt T-Wave Alternans as measured by the QUEST with T-Wave Alternans Option in patients with known or suspected ventricular tachyarrhythmia, or who are at risk of ventricular tachyarrhythmia predicts increased risk of a cardiac event (ventricular tachyarrhythmia or sudden death).

The QUEST with T-Wave Alternans Option should be used only as an adjunct to clinical history and the results of other non-invasive and/or invasive tests. The interpretive results of the Alternans Report Classifier software should be reviewed by a qualified physician.

The predictive value of T-Wave Altemans for cardiac events has not been established in patients with active, untreated ischemia.

*Microvolt T-Wave Alternans is defined as T-wave alternans which a) is measured from high-resolution multi-segment sensors, b) is present in leads X, Y, Z, VM, or two adjacent precordial leads, c) is at the level of 1.9 microvolts after signal optimization and subtraction of the background noise level, d) is at least three standard deviations greater than the background noise level, e) has an onset heart rate of below 110 beats per minute, and f ) is sustained for all heart rates above the onset heart rate.