Complications associated with defibrillation threshold testing: the Canadian experience.

Area of Science:

• Cardiac Electrophysiology
• Medical Device Safety
• Clinical Risk Assessment

Background:

• Historically, defibrillation threshold (DFT) testing was standard during implantable cardioverter-defibrillator (ICD) implantation.
• The routine use of DFT testing is increasingly questioned due to high success rates of modern ICDs and lack of outcome-predictive evidence.
• Intraoperative DFT testing may represent the highest acute risk during ICD implantation procedures.

Discussion:

• This study systematically documented complications directly linked to intraoperative DFT testing across Canadian ICD centers.
• Data from 19,067 ICD implants between 2000 and 2006 were analyzed for DFT-related adverse events.
• The findings highlight the need to re-evaluate the risk-benefit ratio of routine DFT testing in contemporary practice.

Key Insights:

• Three DFT testing-related deaths, five strokes, and 27 prolonged resuscitation episodes were recorded.
• Two patients experienced significant clinical sequelae following prolonged resuscitation.
• The observed complication rate, though seemingly small, suggests a measurable risk associated with DFT testing.

Outlook:

• The study suggests that the risks of severe complications from intraoperative DFT testing, while small, warrant careful consideration.
• Underestimation of the true complication rate is possible with the current study methodology.
• Further data from prospective ICD registries and clinical trials are essential for a comprehensive risk-benefit assessment.