Key Points
- This study aims to investigate the organization of electrical activation during ventricular fibrillation by analyzing epicardial activation directions.
- Thirteen dogs with myocardial infarction and four without had ventricular fibrillation induced.
- Epicardial activation was mapped using a plaque electrode array to create vector loops during each beat.
- Stepwise linear regression evaluated spatial and temporal linking of activation directions at multiple sites.
- The correlation coefficient (r) for linking ranged from 0.64 to 0.88 during early VF and reduced to 0.39-0.78 as VF established (p < 0.0001).
- Spatial linking was found to be more prominent than temporal linking during episodes of VF.
- Presence of myocardial infarction and repeated VF inductions did not affect the degree of linking.
Structured PICO
PPopulation17 dogs (13 with healing myocardial infarction and 4 without MI)
IInterventionVentricular fibrillation induced by programmed stimulation, mapped using a plaque electrode array with a 2.5-mm interelectrode distance
OOutcomeSpatial and temporal linking of epicardial activation directions (measured by correlation coefficient r using stepwise linear regression)surrogate
Electrical activation during ventricular fibrillation in dogs is organized, with spatial linking being more prominent than temporal linking, though the degree of organization decreases during the first 5 seconds.