If a substance inhibits certain potassium channels in the heart muscle, the so-called hERG channels, occur with high probability of cardiac arrhythmias. A team around the pharmacist Steffen Hering has now discovered that these rhythmic disturbances do not necessarily have to occur: if a calcium channel is "blocked" at the same time, damage to the heart can be prevented. Studies on cardiac cells from human stem cells played a key role. This opens the way for innovations in drug development. [read more]