How drugs can cause life threatening heart rhythm disturbances

Evaluation of the roles of pore-helix residues in pharmacological inhibition of the hERG potassium channel, using structure-activity studies with drug analogues

For the heart to pump blood around the body efficiently, electrical signals must travel through the chambers of the heart in an organised and rhythmic way. These signals are co-ordinated by proteins in heart cells called ion channels. A diverse range of drugs can interact with channels and disrupt the signals in the heart, putting patients at risk of abnormal heart rhythms or even death. With these risks in mind, an understanding of how these complications arise is in need. In this study, Dr Dempsey at the University of Bristol has been awarded a PhD studentship to look at a channel in the heart called hERG that is crucial to normal cardiac function. In particular, they are exploring the channel’s structure to understand how some drugs interact with hERG and cause problems. Some drugs used to treat disorders with no relation to heart disease can disrupt a particular channel in the heart called hERG. Understanding the mechanisms behind adverse effects involving hERG could help scientists avoid these risks when developing drugs in the future.