capture failure
The inability of a pacing pulse to initiate myocardial depolarization despite adequate electrical stimulation.
Full Definition
Capture failure represents loss of effective cardiac stimulation despite delivery of pacing pulses at or above the previously established capture threshold. This can result from lead dislodgement, increased stimulation threshold due to tissue changes, lead insulation failure, or loose connections. Acute capture failure may occur immediately post-implantation due to lead displacement, while chronic failure typically develops gradually from fibrotic tissue formation at the electrode-tissue interface. Diagnosis involves observing pacing artifacts without subsequent cardiac depolarization on ECG. Treatment may require increasing pacing output, lead repositioning, or lead replacement depending on the underlying cause.
Usage
Usage note: Always specify the chamber (atrial or ventricular) when documenting capture failure.
In Context
- "Ventricular capture failure was noted during routine device interrogation despite maximum output." — Device clinic assessment
- "The patient's capture failure resolved after lead repositioning in the emergency department." — Emergency procedure note