The Effect of an Azygos Vein Coil on Defibrillation Threshold

NCT ID: NCT00798174

Last Updated: 2018-09-28

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 32 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2008-12-15
• Study Completion Date: 2009-11-18

Brief Summary

When implantable cardiac defibrillators are implanted (ICDs), the defibrillation threshold (DFT), of the amount of energy required to effectively terminate life-threatening arrhythmias is determined. The device is then programmed to discharge a larger amount of energy in order to provide a safety margin. In some patients, the DFT is so high, that an adequate safety margin is not programmable. Placement of a defibrillation lead in the azygos vein has been found to be helpful in these patients. This goal of this trial is to attempt to quantify the average reduction in the DFT (if any) that results from the addition of the azygos lead.

Detailed Description

Patients undergoing placement of an ICD for the primary or secondary prevention of sudden cardiac death will be asked to participate. Patients will undergo implantation of a standard right ventricular ICD lead at the time of ICD implantation. In addition, patient will receive another high voltage ICD lead placed in the azygos vein as has been previously described in the literature (1). After sedating the patient, the DFT will be determined using a binary search algorithm. This consists of testing the device at a given output for the first shock after inducing ventricular fibrillation (VF). Should the shock fail, external defibrillation will be attempted, as is the standard method for performing DFT testing. As per the standard method of DFT testing, VF will be induced a second time, with the shock strength dependent on the success of the first shock. If the first shock was unsuccessful, the second will be at a higher output. If the first shock was successful, the second will be at a lower output. A third shock will then be delivered, based on the success or failure of the preceding shock to define the DFT. Of note, as the device can be programmed to give multiple shocks for one episode, VF will not necessarily need to be induced each time. For example, VF could be induced, and the device programmed to give a 20 Joule (J) shock followed by a 23J shock if not successful, thus limiting the number of VF inductions required. DFT testing will be done using both the standard configuration of high voltage leads as well as using the azygos lead. We hypothesize that using the azygos lead will result in a lower DFT.

Conditions

Heart Failure

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Standard configuration vs. azygos coil

The DFT with the standard Superior Vena Cava (SVC) coil vs. DFT with the azygos coil.

In this crossover study, each patient serves and own control, with defibrillation testing performed with and with the azygos coil

Group Type: EXPERIMENTAL

Standard configuration vs. azygos coil

Intervention Type: DEVICE

Addition of an azygos vein defibrillation coil instead of a standard SVC coil.

Interventions

Standard configuration vs. azygos coil

Addition of an azygos vein defibrillation coil instead of a standard SVC coil.

Intervention Type: DEVICE

Other Intervention Names

Medtronic 6937A Lead

Eligibility Criteria

Exclusion Criteria

• Any contraindication to ICD or the inability to place an azygos vein coil.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Medtronic

INDUSTRY

Sponsor Role: collaborator

Washington University School of Medicine

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Timothy W. Smith, DPhil, MD

Role: PRINCIPAL_INVESTIGATOR

Washington University School of Medicine

Locations

Washington University

St Louis, Missouri, United States

Countries

United States

References

Cooper JA, Latacha MP, Soto GE, Garmany RG, Gleva MJ, Chen J, Faddis MN, Smith TW. The azygos defibrillator lead for elevated defibrillation thresholds: implant technique, lead stability, and patient series. Pacing Clin Electrophysiol. 2008 Nov;31(11):1405-10. doi: 10.1111/j.1540-8159.2008.01203.x.

Reference Type: BACKGROUND

PMID: 18950297 (View on PubMed)

Cesario D, Bhargava M, Valderrabano M, Fonarow GC, Wilkoff B, Shivkumar K. Azygos vein lead implantation: a novel adjunctive technique for implantable cardioverter defibrillator placement. J Cardiovasc Electrophysiol. 2004 Jul;15(7):780-3. doi: 10.1046/j.1540-8167.2004.03649.x.

Reference Type: BACKGROUND

PMID: 15250862 (View on PubMed)

Other Identifiers

08-0045

Identifier Type: -

Identifier Source: org_study_id