To pump blood around our bodies effectively, heart muscle cells contract and relax in a rhythmic way. Contraction and relaxation occurs partly through the controlled flow of calcium ions around the cells, and faults can cause sometimes life-threatening irregularities in our heart’s rhythm, called arrhythmia.
One common heart rhythm disturbance is Long QT syndrome. Long QT is a genetic, inherited, condition that is linked to the flow of charged particles - like potassium and calcium - around the cells in the heart. Kelley's Long QT caused her to lose consciousness in a swimming pool as a child and she knew that she could pass it on to her children but it was still a shock when her newborn son, Jayson, was diagnosed with Long QT.
A route for calcium release
Professor Williams is an internationally respected expert in the control of this vital calcium flux.
With each heart beat an increase in free calcium inside heart muscle cells results in contraction, and a return to resting levels brings about relaxation.
Most of the calcium that activates contraction comes from a store within the cell itself, called the sarcoplasmic reticulum (SR). Calcium moves in and out of this store in a tightly regulated way.
Professor Williams' research focus is on an important route through which calcium is released into the cell from the SR – a giant protein structure in the SR membrane called the ‘SR calcium-release channel’ (also known as the ryanodine receptor).
The Cardiff team use biophysical, biochemical and molecular biological techniques to monitor the function of individual channel molecules. The way the channel's structure influences its function is investigated using sophisticated computer simulations of the channel developed in collaboration with researchers North America.
These studies are revealing the structural adaptations of the SR calcium-release channel that underlie its fundamental role in maintaining the normal function of the heart.
Sudden cardiac death
Recently we’ve begun to understand that faults in the SR calcium-release channel may play an important role in initiating irregular heart rhythms and sudden death in certain inherited and acquired heart conditions.
In Cardiff, Williams works closely with other world-leading experts in this field to understand how changes in calcium-release channel function bring about these dangerous changes in heart rhythm. In the long term, this research will feed into the development of focused therapies to prevent these tragic events.
Read more about our achievements in research into sudden arrhythmic death syndrome.