Clinical practice with regard to defibrillation threshold (DFT) testing during implantable cardioverter-defibrillator (ICD) implantation varies considerably, even among experienced implanting centers. International guidelines do not as yet mandate DFT testing.

The objective of this project is to assess current clinical decision making regarding DFT testing during ICD implantation.

The ALIVE project collected data on DFT testing from a multicenter network of Italian clinicians sharing a common system for the collection, management, analysis, and reporting of clinical and diagnostic data from patients with Medtronic (Minneapolis, MN) implantable devices.

Data on 2,082 consecutive patients implanted with a Medtronic ICD in 111 Italian centers, over the period 2007 to 2010, were analyzed. Defibrillation threshold testing was performed in 33% of cases (678/2,082). The main reasons for performing the test were physician's clinical practice (“I always perform DFT”) (80%) and secondary prevention implantation (12%). The main reasons for not performing DFT testing were centers' practice (44%), primary prevention (31%), and device replacement (15%). In 22 patients, ventricular fibrillation induction was not achieved; 656 patients completed DFT testing: 633 patients (96%) performed a single test, 19 patients (3%) performed a second induction test, and 4 patients (0.6%) underwent an additional induction test.

The preliminary results of the ALIVE project show that a great number of implant procedures are performed without DFT testing in the common practice of the participating centers. We also measured an inhomogeneous, center-dependent DFT testing behavior, which suggests the importance of defining a common guideline for ICD implant testing. Follow-up data on our patients will provide more information on the clinical value of the test.