Dr. Alexander Quinn
Tapping into a feedback loop: Dr. Alexander Quinn seeks mechanical solutions to electrical problems in the heart
There are many different kinds of arrhythmias - irregular heartbeats - that can lead to problems from dizziness and fatigue to heart failure and sudden death. Dr. Alex Quinn is looking for new ways to prevent and treat rrhythmias, by studying how the mechanical function of the heart impacts its electrical activity.
"Arrhythmias are caused by disturbances of the heart's electrical activity, but the underlying problem is often mechanical," Dr. Quinn explains. "For instance, as a person ages or develops heart disease scarring occurs, which alters the heart's stiffness, affects its contraction, and causes regions of stretch. Theses changes act as triggers for deadly arrhythmias."
Of course, electrical disturbances themselves cause mechanical problems. "Scarring also disrupts the transmission of electrical signals in the heart," notes Dr. Quinn. "The heart then becomes less efficient, so has to work harder to pump blood. Ultimately that mechanical dysfunction interferes even further with the electrical activity, and so on and so forth, creating a vicious cycle that can drive the progression of heart failure."
To date, there has been relatively little success in managing arrhythmias with drugs. Current treatments include electrical devices like implantable pacemakers and defibrillators or invasive procedures like catheter ablation and surgery. By discovering how heart mechanics influences electrics, Dr. Quinn hopes to open the door to new therapeutics targeting this mechano-electric feedback loop.
"This year's Molly Appeal will support one of the key elements for the translation of our findings to people: access to a library of tissue samples from heart failure patients," says Dr. Quinn. "Using this resource, we can strengthen our collaborations with Dalhousie researchers in Halifax, such as Dr. Susan Howlett, and Dr. Kishore Pasumarthi, and establish new links with our DMNB colleagues in Saint John to develop innovative treatments designed specifically to eliminate arrythmias and break the heart failure loop."