Ventricular conduction stability test: a method to identify and quantify changes in whole heart activation patterns...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Imaging

Background:

• Abnormal heart rate adaptation can be proarrhythmic and is challenging to measure with existing electro-anatomical mapping.
• Quantifying spatial discordance in whole heart activation during rate changes is crucial for understanding cardiac arrhythmias.

Purpose of the Study:

• Develop a rapid method to quantify spatial discordance in whole heart activation following rate changes.
• Test if patients with channelopathies or aborted sudden cardiac death (SCD) show reduced uniform activation after exercise.

Main Methods:

• Electrocardiographical imaging (ECGI) was used to create detailed epicardial activation maps from >1200 electrograms (EGMs).
• Thirty-one individuals (SCD survivors, Brugada syndrome patients, controls) underwent ECGI recordings pre- and post-exercise.
• A ventricular conduction stability (V-CoS) score was calculated to measure conduction heterogeneity based on local activation time (LAT) changes.

Main Results:

• ECGI successfully mapped whole heart activation, showing good reproducibility of V-CoS scores.
• Sudden cardiac death survivors demonstrated significantly lower V-CoS scores post-exertion compared to Brugada syndrome patients and controls.
• No significant difference in V-CoS scores was observed between groups at baseline.

Conclusions:

• A novel method for rapidly quantifying changes in global heart activation and conduction heterogeneity is presented.
• The study provides proof of concept, showing that SCD survivors have a diminished capacity to maintain uniform ventricular activation after exercise.
• This technique offers a new tool for assessing proarrhythmic potential related to conduction abnormalities.