During a heart attack the flow of blood to a section of heart muscle suddenly becomes blocked by a clot.
Some people survive a heart attack and make it to the hospital in time to have the clot removed. Others are not so
lucky: a deadly storm of electrical activity in the heart causes an arrhythmia, an irregular rhythm of the heartbeat,
and they die before they can be treated.
Why do deadly arrhythmias develop during a heart attack in some people and not others? This is the question that
Professor Matthew Kay of the Department of Electrical and Computer Engineering and his colleagues are trying to understand.
Although there is nothing unusual about grappling with this question-other researchers around the world are doing
the same-Kay and his team are taking a unique approach to trying to solve the puzzle.
The state-of-the-art for basic science arrhythmia research revolves around florescence imaging, a way to optically
map out the flow of electrical potential during an arrhythmia. The imaging is conducted using hearts taken out of
animals, but still supported, so that the entire surface of the heart can be clearly seen. A limitation of
florescence imaging is that information is lost when the heart contracts. As long as the heart is motionless,
good imaging data can be obtained, but as soon as it begins to contract the data are distorted.
Most researchers, therefore, shut down that mechanical activity when using fluorescence imaging.
Kay's team takes a different approach.
"We want to understand how cardiac metabolism changes before and during an arrhythmia.
The contraction of the heart is the main consumer of energy and, therefore, is the main player in metabolic activity.
Stopping the process of contraction is probably the worst thing we can do if we want to understand how metabolism
causes electrical disturbances," explains Kay. "One of our goals is to make florescence imaging work
without shutting down the mechanical activity."
To do this, he and his team have built instrumentation systems to keep the heart contracting and to simulate a heart
attack. The heart is then imaged to record simultaneously the electrical and metabolic processes. "We've developed a
heart support system that provides a warm, oxygenated blood substitute to each atrium. When the heart contracts, it
generates pressure, circulates the solution, and pumps the blood substitute to itself. Basically, the instrumentation
supports the heart almost as if the heart were in the body," says Kay.
This unique approach puts GW at the forefront of conducting studies that link metabolism and electrical alterations
within the context of contraction. As Kay says, "We are probably one of just a very few labs in the world that are
conducting these kinds of experiments. This is the first system of this type ever built. This is where we are diverging
from others who are studying arrhythmias, this is where we are charting new ground."