Embed Size (px)
Citation preview
Workshop on Atrial Fibrillation
Group 6
The most common type of arrhythmia (irregular heartbeat)
In AF, atria contract very fast and irregularly. Atria get pooled by blood. Blood not being able to go into ventricles completely. Consequently, atria and ventricles do not work
together. The heart’s electrical signals do not begin in the SA
node. Signals begin in another part of the atria or in
pulmonary veins and they don’t travel normally. The amount of blood pumped by ventricles to the body
depends on atrial beats.
Atrial Fibrillation
Interesting patterns seen in many experiments. Example: Belousov- Zhabotinsky
Usually rotate without changing their shapes
The tip traces out a perfect circle After getting destabilized, they either drift
or meander.
Spiral Waves
Inward meandering
Outward meandering
Drifting Spiral Waves
Parameters
GNa – Conductance for fast Na+ channel
kNaCa – Current for Na+/Ca2+ exchanger
Na+/Ca2+ exchanger- An antiport, where three Na+ are brought in for one Ca2+, when the membrane potential is negative and when the
cell is depolarized, Na+ leaves and Ca2+ enters.
GNa vs kNaCa
Spiral Wave of Day 1
GNa
KNaCa
Maxim
al I N
a
con
du
cta
nce
Maximal INaCa
Path of Day 1
GNa
Maxim
al I N
a
con
du
cta
nce
KNaCaMaximal INaCa
Spiral wave Day 2
GNa
Maxim
al I N
a
con
du
cta
nce
KNaCaMaximal INaCa
Path of Day 2
GNa
Maxim
al I N
a
con
du
cta
nce
KNaCaMaximal INaCa
Day 1 VS. Day 2Wave Comparison
Day 1 VS Day 2Trajectory Comparison
Conclusions:
• Spiral waves are influenced by the concentration of Ions.
• Different shape of the spirals depending on which concentration is changed first.
• Low concentration of Sodium Calcium exchanger and high concentration of Sodium produces trajectories that are more chaotic.
• High Sodium-Calcium concentration and low Sodium concentration produces spiral trajectories that are tight.
Nancy Griffeth Flavio Fenton Robert Gilmour Bard Ermentrout Aron Wolinetz Charles Beard Rachel Spratt All participants
Acknowledgement
