Cornell scientists, in collaboration with physicists and physician-scientists in Germany, France and Rochester, N.Y., have developed a new — and much less painful and potentially damaging — method to end life-threatening heart fibrillations.
The new technique, which is reported in the July 14 issue of the journal Nature, cuts the energy required for defibrillation by 84 percent, compared with conventional methods.
In healthy hearts, electrical pulses propagate across the heart muscle in an orderly fashion to control the heart’s contraction and relaxation cycle at regular intervals. However, when the electrical pulses propagate throughout the heart chaotically, it disables the regular heartbeat and prevents the body from getting fresh supplies of blood.
The video (click link at the bottom) depicts an arrhythmia (spiral waves) during fibrillation, showing very complex spatiotemporal dynamics. Around frame 1700, the low energy pulses are introduced and little by little one can see the synchronization and eventual termination of the arrhythmia.
One of these rhythm disturbances, called atrial fibrillation, is the most common sustained cardiac arrhythmia worldwide, affecting about 1 percent of the population, mostly people older than 50 years.
Patients who suffer repeatedly from atrial fibrillation are typically treated with a large electrical pulse (defibrillation), which forces the heart back into its regular beating but is painful and can damage the surrounding tissue. The new method, LEAP (Low-Energy Anti-fibrillation Pacing), developed by a team co-led by Cornell College of Veterinary Medicine researcher Flavio Fenton, uses a heart catheter to create a sequence of five weak electrical signals in the heart.
“Only a few seconds later, the heart beats regularly again,” said the team’s other co-leader, Stefan Luther of the Max Planck Institute for Dynamics and Self-Organization (MPI DS) and a Cornell adjunct professor in biomedical sciences.
“The energy applied to the heart per pulse is on average 84 percent less than in conventional methods,” added Fenton.