inappropriate shock
Delivery of defibrillation therapy by an ICD for rhythms that do not warrant defibrillation treatment.
Full Definition
Inappropriate shock refers to ICD therapy delivery for rhythms that are either non-life-threatening or result from device malfunction rather than true ventricular tachyarrhythmias. Common causes include atrial fibrillation with rapid ventricular response, sinus tachycardia exceeding programmed rate cutoffs, lead fracture generating noise, or electromagnetic interference. These shocks cause significant patient distress, potential psychological trauma, and unnecessary battery depletion without clinical benefit. Modern ICDs incorporate multiple discrimination algorithms including sudden onset, stability, and morphology analysis to minimize inappropriate therapy. Programming optimization and enhanced detection algorithms have significantly reduced inappropriate shock rates in contemporary devices.
Usage
Usage note: Always document the underlying rhythm that triggered inappropriate therapy in device reports.
In Context
- "The patient received an inappropriate shock for atrial fibrillation that was incorrectly classified as ventricular tachycardia." — Device event analysis
- "Modern discrimination algorithms have reduced inappropriate shock rates to less than 10% annually." — Clinical study findings