A Clinical Evaluation of ST Changes in a Group of Patients Having Ventricular Arrhythmias
A Clinical Evaluation of ST Changes in a Group of Patients Having Ventricular Arrhythmias
The purpose of this investigation is to determine the prevalence of device-recorded ST
 segment changes occurring before appropriate Implantable Cardiac Defibrillator (ICD)
 therapies (ATP or Shock) and to define their temporal relationship to ventricular
 arrhythmias.
Sudden cardiac death due to cardiac arrhythmia is a devastating and unpredictable
 complication of coronary artery disease.

 Implantation of automatic implantable cardioverter defibrillators (ICD) is a well established
 therapy for the treatment and prevention of sudden cardiac death. Evidence for the use of
 these devices has been provided by a number of landmark clinical trials over the last 16
 years.

 Reduction in ischemia can be achieved by coronary artery revascularization but in many
 patients may occur a gradual progression to recurrence of ischemia resulting in further life
 threatening arrhythmias. It is reasonable to assume that unchecked progression of ischemic
 heart disease may result in increased mortality in ICD patients. It has been shown that the
 long term mortality risk for ICD patients can be linked to the time since the last coronary
 revascularization procedure. Both MADIT-II and Sudden Cardiac Death in Heart Failure trial
 (SCD-HeFT) showed that patients receiving inappropriate ICD therapy have an increased risk of
 death. It has been speculated that this may be due to progression of the disease and
 recurrent ischemia.

 A feature available in some ICDs manufactured by St Jude medical enables the constant beat to
 beat monitoring of the intra-cardiac ST segment using the implanted ICD leads. Similar
 systems have demonstrated this approach to be a reliable method of identifying ischemic
 events. However, the predictive value of the ST monitoring feature in identifying pending
 arrhythmic events has yet to be established. Prediction of worsening ischemia could play an
 important part in allowing physicians to identify ICD patients with greater mortality risk
 and allow them the time to personalize patient therapy in order to reduce that risk.
Inclusion Criteria:

 -  The patient is implanted with an St Jude Medical (SJM) ICD with ST Monitoring and
 ShockGuard™ features (and remote care feature in case Merlin.net will be used)

 -  The patient, in the opinion of the investigator, will not require ventricular pacing
 for more than 20% of the time.

 -  The patient, in the opinion of the investigator, has or is at high risk of Coronary
 Artery Disease (CAD).

 -  The patient is ≥ 18 years of age.

 -  The patient is able to provide written Informed Consent prior to any investigational
 related procedure.

 Exclusion Criteria:

 -  The patient has longstanding persistent Atrial Fibrillation (AF) /Atrial Flutter (AFl)
 or permanent AF/AFl

 -  The patient has documented complete heart block.

 -  The patient is known to have uncontrolled ventricular bigeminy or trigeminy (PVCs on
 regular basis).

 -  The patient has severe Left Ventricular Hypertrophy resulting in interventricular
 conduction defect (IVCD).

 -  The patient has intermittent bundle branch blocks (BBB).

 -  The patient is unable to comply with the follow up schedule.

 -  The patient is participating in another investigational device or drug investigation.

 -  The patient is pregnant or is planning to become pregnant during the duration of the
 investigation.