Observation of ImageReady™ MR Conditional Defibrillation System in China

To observe the safety and effectiveness of ImageReady™ MR conditional defibrillation system in a Chinese population.

This is a multi-center, prospective, single-arm study, aimed to observe the safety and effectiveness of ImageReady™ MR conditional defibrillation system in a Chinese population.It will enroll 20 subjects in 5 sites in China.The primary safety endpoint is MR scan-related Complication-free rate between the MR Scan and the MRI + 1 Month Visit. The primary effectiveness endpoints include:1.Abnormal increase in RV shocking impedance from the pre-MR scan to the 1 Month post-MR scan. 2.Increase in RV pacing threshold from the pre-MR scan to the 1 Month post-MR scan. 3.Decrease in RV sensed amplitude from the pre-MR scan to the 1 Month post-MR scan. 4.Increase in LV pacing threshold from the pre-MR scan to the 1 Month post-MR scan. 5.Decrease in LV sensed amplitude from the pre-MR scan to the 1 Month post- MR scan.

Eligibility Criteria:
Inclusion Criteria:

1. Subject is indicated to Class I/II indications per guidelines/consensus released by Chinese Society of Cardiac Pacing and Electrophysiology
2. Subject must have the ImageReady System as their initial (de novo) defibrillation system implant
3. Subject will receive an ICD or CRT-D pulse generator in the left or right pectoral region ICD
4. Subject is able and willing to undergo an MR scan
5. Subject is willing and capable of providing informed consent and participating in all testing/ visits associated with this clinical study at an approved clinical study center and at the intervals defined by this protocol
6. Subject is age 18 or above

Exclusion Criteria:

1. Subject has other active or abandoned implanted cardiac rhythm devices, components or accessories present such as pulse generators, leads, lead adaptors or extenders
2. Presence of metallic objects that represent a contraindication to MR imaging at the discretion of the Radiologist and impacting the ability to conduct the study protocol
3. Subject needs or will need a medically necessary MR scan, before completing the 1-month post-MR follow-up visit
4. Subject with:

   * A history of syncope related to brady-arrhythmia
   * A history of syncope of unknown etiology
   * Sinus pauses (Pause \> 2 s)
   * Permanent or intermittent complete AV block
   * Documentation of progressive AV nodal block over time
   * Trifascicular block (alternating bundle branch block or PR \> 200 ms with LBBB or other bifascicular block)

     * Note: It is required to run a 12 lead ECG and a 10s rhythm strip to document this exclusion criterion.
5. Subject is not clinically capable of tolerating the absence of pacing or Resynchronization therapy support in a supine position for the duration that the pulse generator is in MRI Protection Mode, per Physician discretion
6. Subject is not clinically capable of tolerating the absence of Tachycardia therapy support for the duration that the pulse generator is in MRI Protection Mode, per Physician discretion
7. Subjects currently requiring dialysis
8. Subject has a mechanical heart valve
9. Subject has a known or suspected sensitivity to dexamethasone acetate (DXA)
10. Subject is currently on the active heart transplant list
11. Subject has documented life expectancy of less than 12 months
12. Subject is enrolled in any other concurrent study that might interfere with this study
13. Women of childbearing potential who are or might be pregnant at the time of this study