(University of Bonn) Life-threatening cardiac arrhythmias often occur after a heart attack, as the scar tissue can interfere with the spread of electrical impulses that activate the heart. An international research team under the leadership of the University Hospital Bonn in collaboration with colleagues from the Cornell University and the University of Pittsburgh has now developed a method to improve electrical transmission in the heart by transferring a single gene, Connexin 43, to cells that form the infarct scar.