active fixation
A lead attachment mechanism using a retractable helical screw to anchor the electrode to cardiac tissue.
Full Definition
Active fixation refers to a lead design that employs a small helical screw mechanism at the electrode tip to secure the lead to cardiac tissue. The screw can be extended or retracted using a stylet, allowing the physician to actively engage the myocardium during implantation and providing stable lead positioning. Active fixation leads offer advantages in challenging anatomical situations, such as smooth atrial walls or dilated chambers where passive fixation might be inadequate. The screw mechanism also allows for lead repositioning during implantation if initial placement is suboptimal.
Usage
Usage note: Hyphenate when used as a compound modifier: 'active-fixation lead'.
In Context
- "Active fixation was chosen for the atrial lead due to the patient's enlarged right atrium." — Implant procedure note
- "The active fixation mechanism allowed for optimal lead repositioning during implantation." — Surgical case summary