Cardiac Pacemaker Cells (IMAGE) Rockefeller University Press Caption This is a close-up view of cardiac pacemaker cells within the sinoatrial node. A study in The Journal of General Physiology shows a novel role for IKACh in cardiac pacemaker activity and heart rate regulation. Credit Mesirca et al., 2013 Usage Restrictions Reporters may freely use these materials in news coverage, with the appropriate credit information. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.