A multidisciplinary team of University of Wisconsin researchers has received a $9.77 million grant to research the causes and possible treatments of sudden cardiac arrest from the National Heart, Blood and Lung Institute.

UW professor of physiology Hector Valdivia said the grant will fund study of two heart problems –enlargement of the heart known as hypertrophic cardiomyopathy and irregular heart beat known as arrhythmia caused by cell mutations.

Valdivia said the enlargement of the heart is a common problem in athletes and active people, adding both problems can cause the heart to arrest, or stop.

He said the project has four principal investigators, each of whom will take the lead on a different subset of research. He said the grant reviewers were very happy with this approach.

“The reviewers thought it was a very synergistic way of doing it,” Valdivia said.

He said he and professor of pediatrics at the Mayo Clinic Medical School Michael Ackerman will focus on how calcium imbalances are handled in cells, and how they cause disturbances and problems within the heart.

Valdivia said there have been examples of clinical cases which say this issue is very significant in sudden cardiac arrest.

UW professor of physiology Richard Moss said the disturbances that cause sudden cardiac arrest are often electrical disturbances within the heart.

The cause of these disturbances can be inherited abnormalities –a gene mutation which may be recurrent in successive generations — or acquired abnormalities –usually caused by another primary disease. He added heart failure is one thing that can cause an acquired abnormality.

Moss said his research will focus on calcium triggered arrhythmias, and he will look at cardiac cells. He will study the cell membranes, the internal membranes and the proteins that generate heartbeats.

Valdivia said the fourth principal investigator, UW professor of cardiovascular medicine Jonathan Makielski, will study the ion channels of the surface membranes and how these membranes cause heart contractions.

Both Moss and Valdivia said the primary goal of the research is to understand what causes these serious heart problems.

“The principal goal at this stage is to understand the basis for the arrhythmias,” Moss said.

Valdivia said no testing for practical measures can be done until researchers have a fundamental understanding of what goes wrong in calcium triggered arrhythmia patients.

Once they understand what causes the problems, they can begin testing practical strategies for mitigating, or even eliminating, the problems, Valdivia said.

He added he personally will be looking for a strategy that can quench the release of calcium to reduce arrhythmias. That strategy may involve inhibitors or beta blockers.

Moss said beta blockers are a strategy that is already successfully employed against arrhythmias, but he thinks this research will lead toward more strategies.

“Ultimately the goal is to reduce the incidents of sudden cardiac arrest… caused by these arrhythmias we are studying,” Moss said.