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
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.