The primary objective of the study was to observe if there are any detectable ST segment changes on an electrogram (EGM) signal from an implanted cardiac defibrillator (ICD) during myocardial infarctions among study participants.

During the study, none of the subjects presented with a ST Elevation Myocardial Infarction (STEMI). Therefore, there was not the opportunity to measure the hearts electrical activity during one of these events.

During the study, spontaneous coronary ischemic events were categorized as STEMI, Non-ST elevated myocardial infarction (NSTEMI), or Unstable Angina. This objective was to provide estimates of rates per patient year for the study population. Rates are presented as: Average number of events per patient year (95% Confidence Interval)

There were 175 subjects that consented to participate in the study, and two subjects were not implanted with an ICD by the time the study was terminated. Therefore data collected by the implanted ICD in the remaining 173 subjects was analyzed.

Patients underwent an exercise stress test at their one month study visit. This objective was to summarize the magnitude of the hearts electrical activity signal measured by the implanted ICD during a positive exercise stress test for ischemia.

The device in this study included an additional capacity to collect and store information about the hearts electrical activity specific to ischemic heart disease. This additional capacity of the device is not currently available in market release ICDs. There is no measure to this objective, other than reporting the number of follow-up years of data accrued, which can be used by Medtronic for additional research.

There were 175 subjects that consented to participate in the study, and two subjects were not implanted with an ICD by the time the study was terminated. Therefore the number of years of stored device data to utilize for future research as collected by the implanted ICD in the remaining 173 subjects was analyzed.

When study subjects completed their six-month follow-up visit, they were asked if they would consent to wear a Holter monitor for a period of 24 hours to collect Heart Sounds data. The study subject would have to return to the center the following day to return the Holter monitor and have their ICD EGM vectors reprogrammed.

A subset of participants opting to wear a Holter monitor for 24 hours to collect Heart Sounds data, and then returning the following day for device reprogramming.