Diastolic Pathway Potential
Low-amplitude electrical signal recorded during VT that represents slow conduction through protected isthmuses in scar tissue.
Full Definition
Diastolic pathway potentials are low-amplitude, often fractionated electrical signals recorded during ventricular tachycardia that occur during the diastolic period between QRS complexes. These signals represent slow conduction through protected pathways or isthmuses within areas of myocardial scar. Recording sites with diastolic pathway potentials are critical components of the VT circuit and represent optimal targets for ablation. Elimination of these potentials during radiofrequency application often results in VT termination and indicates successful modification of the arrhythmia substrate.
Usage
Usage note: Timing relative to QRS complex is critical for identification. Indicates protected conduction pathways.
In Context
- "Diastolic pathway potentials were recorded 40 ms after the QRS during sustained VT, identifying the critical isthmus." — Electrophysiology study
- "Ablation at sites with diastolic pathway potentials resulted in immediate VT termination." — Ablation report