Safety of Cardiac Pacemakers in 1.5T Tesla MRI

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00336011
Recruitment Status : Completed
First Posted : June 12, 2006
Last Update Posted : June 12, 2006
Information provided by:
University Hospital, Bonn

Brief Summary:
To evaluate short-term and long-term effects by MR imaging on the technical and functional status of Medtronic pacemakers.

Condition or disease Intervention/treatment
Heart Diseases Device: Magnetic resonance imaging

Detailed Description:

The presence of a cardiac pacemaker (PM) is currently considered an absolute contraindication to MR imaging, and most patients with PM are excluded from having MRI. In 2002 there were approximately 2.4 million patients in the US with cardiac PM, and this number is growing by 80,000 annually. A previous study has shown that MRI is indicated in 17% of all patients with pacemakers within 12 months of device placement 1, demonstrating the need for a practical and safe approach for performing MRI on PM patients.

The aim of this study is to develop a strategy for safe performance of MR imaging at 1.5T, which included exclusion of pacemaker dependent patients and those requiring imaging of the thorax, restriction of specific absorption rate (SAR) values to minimize the risk of lead heating, and PM reprogramming to avoid interference from time varying gradient fields. The safety of this approach is then evaluated in a large group of PM patients including assessment of potential myocardial thermal injury by measuring serum troponin I and pacing capture thresholds, and performing a 3-month follow-up to evaluate long-term effects.

Study Type : Observational
Enrollment : 75 participants
Observational Model: Defined Population
Observational Model: Natural History
Time Perspective: Longitudinal
Time Perspective: Prospective
Official Title: Studie Zur Sicherheit Von Medtronic Schrittmachern Bei Magnetresonanz-Bildgebungsverfahren an 1,5 Tesla-Systemen Study to Evaluate Safety Medtronic Pacemakers in MR Imaging at 1.5T Tesla)
Study Start Date : December 2002
Study Completion Date : January 2006

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Urgent need for an MRI examination
  • Presence of a Medtronic PM system manufactured between 1993 and 2004
  • Stable pacemaker physical parameters

    • Battery voltage > 2.7 V
    • Battery impedance < 2000 Ohm
    • Battery estimated remaining lifetime > 6 months
    • Lead impedances 200-2000 Ohm
  • Stable pacing parameters

    • Pacing capture threshold <2.5V at a pulse duration of 0.4ms
    • Sensing > 5mV
  • Minimum 3 months since pacemaker and lead implantation

Exclusion Criteria:

  • PM system manufacturer other than Medtronic
  • History of ventricular tachycardia (VT) or ventricular fibrillation
  • Unstable angina
  • Myocardial infarction within the previous 3 months
  • Cardiothoracic surgery within the previous 3 months
  • Complete atrioventricular block
  • Absolute pacemaker dependence

    • Heart rate < 40 bpm or
    • Heart rate < 60 bpm producing neurological symptoms
  • Presence of an abdominal pacemaker with lead length > 70 cm
  • Presence of MRI incompatible bioimplants or other MRI incompatible materials
  • Request for an MR examination of the chest, including the heart, breasts and thoracic spine

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00336011

University of Bonn, Department of Radiology
Bonn, NRW, Germany, 53127
Sponsors and Collaborators
University Hospital, Bonn
Principal Investigator: Torsten Sommer, MD University of Bonn, Department of Radiology Identifier: NCT00336011     History of Changes
Other Study ID Numbers: 186/02
First Posted: June 12, 2006    Key Record Dates
Last Update Posted: June 12, 2006
Last Verified: January 2006

Keywords provided by University Hospital, Bonn:
magnetic resonance imaging

Additional relevant MeSH terms:
Heart Diseases
Cardiovascular Diseases