A leading instance in its field.

synonym: pacesetter.

A specialized bit of heart tissue that controls the heartbeat.

synonyms: cardiac pacemaker, SA node, sinoatrial node.

Polish: węzeł zatokowo-przedsionkowy, węzeł SA, węzeł zatokowy, węzeł Keitha-Flacka

An implanted electronic device that takes over the function of the natural cardiac pacemaker.

synonym: artificial pacemaker.

Polish: rozrusznik serca, stymulator serca, rozrusznik, kardiostymulator, sztuczny rozrusznik serca

A horse used to set the pace in racing.

synonyms: pacer, pacesetter.