University of Manchester
Mark Boyett was born in Portsmouth in 1952 and his childhood was spent in England, Africa and Australia. At university, as an undergraduate student, he studied biological sciences and, as a postgraduate student, physiology. Following his Ph.D., Mark was a Royal Society Overseas Fellow at the University of Berne in Switzerland. In 1978 he was appointed a Lecturer in Physiology at the University of Leeds. He remained at the University of Leeds for 26 years and he was appointed a Reader in Physiology in 1991 and a Professor of Physiology in 1995. In 2005 he moved to the University of Manchester as the Professor of Cardiac Electrophysiology. Mark has published ~240 papers and other substantial contributions. His h factor is currently 49. He has held grants totalling ~15.5 million pounds, including four programme grants from the British Heart Foundation. Mark has worked on the electrophysiology of the heart throughout his career. His principle work has been concerned with the ‘cardiac conduction system’, the electrical wiring system of the heart. This system comprises the sinus node, atrioventricular node and His-Purkinje system and it is responsible for the initiation and coordination of the heartbeat. He has described the detailed anatomical structure of the system. Surprisingly, this was not known. For example, the pacemaker of the heart, the sinus node, is always shown in textbooks as a small nodule (not the case) in the wrong location! It is astonishing that generations of cardiac surgeons have been taught the wrong location of the sinus node. He has shown that the sinus node is much more extensive than originally thought – this explains why the heartbeat is first initiated at a range of sites in the right atrium. Another example: he has shown how the structure of the atrioventricular node can explain atrioventricular nodal reentrant tachycardia, a relatively common arrhythmia in young adults. The function of the cardiac conduction system is electrical and it depends on proteins called ‘ion channels’ and Mark has shown the pattern of expression of ~100 ion channels in the cardiac conduction system – it is characteristically different from that in the ordinary muscle of the heart. The cardiac conduction system goes wrong in heart failure and this increases morbidity and mortality. For example, a quarter of heart failure patients have left bundle branch block. It is likely that the cardiac conduction system goes wrong in pulmonary hypertension, following myocardial infarction, and in diabetes and obesity as well. The cardiac conduction system even goes wrong in endurance athletes! Mark has shown that the cardiac conduction system disease is the result of widespread changes in the ion channels. Mark has found nodal cells outside of the cardiac conduction system: in the atria and even the ventricles. In the ventricles, they are found at the root of the pulmonary artery and aorta. These nodal cells do not take part in the normal cardiac cycle. Instead they are probably responsible for a range of atrial tachycardias and the so-called ventricular outflow tract ventricular tachycardias. Mark is producing computer models of the heart with accurate anatomy and accurate electrophysiology. These models are being used to simulate the normal cardiac cycle as well arrhythmias. These models are able to beat and one day pump blood (virtually). These models can be used in teaching, research and drug discovery and will reduce the need for animal experimentation.
Mark Boyett’s research focuses on the “ion channels” of the heart. The heartbeat is initiated by electrical impulses radiating in a coordinated and rhythmic manner from the pacemaker of the heart, the sinoatrial node. The electrical impulses are generated by electrically charged ions (such as sodium, calcium and potassium ions) as they flow across the cell membrane surrounding every cell in the heart via “ion channels”. When the electrical impulses are no longer coordinated, because for example there is a fault with one of the ion channels, the result is a cardiac arrhythmia and this can result in sudden cardiac death. There are probably more than 50 types of ion channels in the heart and Mark’s group are studying (using electrophysiology, immunohistochemistry and in situ hybridisation) which ones are present in the pacemaker. They are also studying the structure of the pacemaker and using E-science they are combining the ion channel and structural data to generate a “virtual pacemaker”, in other words a highly detailed computer model of the pacemaker. This model can be used to study diseases such as sick sinus syndrome and develop new treatments. The group are also studying how the ion channels of the pacemaker work, because it is often naturally-occurring mutations in the ion channels in the heart that result in inheritable diseases such as sick sinus syndrome. For this, they study how mutations that they make in the ion channels alter the functioning of the ion channels. They are also making atomic-resolution models of the ion channels.