Evidence of three-dimensional scroll waves with ribbon-shaped filament as a mechanism of ventricular tachycardia in the isolated rabbit heart

Citation
Ir. Efimov et al., Evidence of three-dimensional scroll waves with ribbon-shaped filament as a mechanism of ventricular tachycardia in the isolated rabbit heart, J CARD ELEC, 10(11), 1999, pp. 1452-1462
Citations number
42
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Journal title
JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY
ISSN journal
1045-3873 → ACNP
Volume
10
Issue
11
Year of publication
1999
Pages
1452 - 1462
Database
ISI
SICI code
1045-3873(199911)10:11<1452:EOTSWW>2.0.ZU;2-K
Abstract
Rotating vortices have been observed in excitable media of different nature , Vortices may sustain life or kill in different species, by underlining mo rphogenesis in Dictiostelium discoideum during starvation, or arrhythmias d uring sudden cardiac death in mammals, Investigation of vortices in the hea rt has been limited by two-dimensional experimental techniques. In contrast , three-dimensional (3D) Belousov-Zhabotinsky excitable medium and mathemat ical models have been shown to sustain scroll-shaped waves, The heart is a 3D structure; therefore, scroll waves may underlie cardiac arrhythmias, Methods and Results: We used potentiometric dye and optical mapping techniq ues to study vortices during ventricular arrhpthmias, The core of all obser ved vortices were linearly shaped and greater than or equal to 9 mm (48 epi sodes, six hearts). As shown by Allessie et al, in the rabbit atrium, ventr icular signals recorded within 1 to 2 mm from the line of block were dual h umped, suggesting there is electrotonic interaction across the line of bloc k. We hypothesized that the line of block represents epicardial intersectio n of ribbon-shaped filaments, which in some cases may be oriented under an angle or parallel to the epicardium. In la episodes we observed dual-humped optical recordings at one side of the line of block at a distance up to 12 mm, The two humps may represent the signatures of two activation wavefront s propagating above and below the filament, which in this area is close to the epicardial surface. The activation sequence of the two waves is consist ent with the idea of a scroll wave with ribbon-like filament. Conclusion: Our data pro,ide new insights into the shape and dynamics of th e filament of the 3D scroll wave, which underlies the mechanism of ventricu lar tachycardia in the rabbit heart. The filament of the scroll wave mag be ribbon shaped, with a significant width greater than or equal to 9 mm and a thickness of 1 to 2 mm, No evidence of fully excitable cells in the core of vortex was observed.