Simultaneous optical and electrical tracking of heart activity

Schematic drawing of the POEMS system. Michael Rieger et. al., aus Nature Communications, doi.org/10.1038/s41467-021-26039-8. It is still elusive to what extent interactions between different cell types of the heart influence the normal heart rhythm and possibly trigger life-threatening arrhythmias. A new measurement method developed at the University of Bern combines for the first time optical and electrical recording of cardiac ventricular activation which, in conjunction with optogenetics, will permit finding comprehensive answers to these questions. The normal function of the heart is based on a pacemaker that generates electrical impulses ('action potentials') which spread rapidly throughout the heart muscle where they trigger the contraction leading to the heartbeat. In the past, it was assumed that the propagation of action potentials was controlled exclusively by cardiac muscle cells.