Scientists in Shanghai have used stem cells to create the world’s first laboratory-grown sinoatrial node – the tiny structure that acts as the heart’s natural pacemaker.

Capable of beating autonomously, the organoid is a breakthrough that researchers say could transform cardiac disease research and drug screening.

The heart’s ability to beat continuously and rhythmically depends on the sinoatrial node, which is nestled inside the right atrial chamber.

Acting as the heart’s “master conductor”, the node continuously sends out electrical signals regulated by the nervous system. These signals dictate when the atria and ventricles – the upper and lower chambers of the heart – should contract, ensuring blood is pumped efficiently around the body.

Should this master conductor fail, the heartbeat can slow to dangerous levels or pause entirely. In severe cases, the condition is life-threatening.

The Shanghai researchers have successfully engineered a biological pacemaker in the lab that could offer a new way to control abnormal heart rhythms.

Using human pluripotent stem cells – which can self-renew and develop into many different cell types – the team constructed a 3D sinoatrial node organoid.