PARIS — Scientists said on Wednesday they had developed the world's tiniest pacemaker, a temporary heartbeat regulator smaller than a grain of rice that can be injected and controlled by light before ...

Defibrillators use electrical shocks to restore a normal heart rate, especially in cases of life threatening arrhythmias or sudden cardiac arrest, while pacemakers use low-energy electrical pulses to ...

Though a Northwestern-developed quarter-size dissolvable pacemaker worked well in pre-clinical animal studies, cardiac surgeons asked if it was possible to make the device smaller. To reduce the size ...