Cardiac physiology - A last wave from the dying heart

What makes a heart beat? Synchronized contraction of cardiac muscle cells, triggered by electrical excitation, causes the ventricles to pump blood around the body. But, in the last few minutes of life, contraction of the ventricular muscle is no longer synchronized — instead, the ventricles ‘fibrillate’ (contract spontaneously) at ten times the frequency of a normal heart beat. Fibrillation was thought to be a chaotic process but, using new imaging techniques, two groups have discovered that there may be much more spatial and temporal order in the process than previously suspected.