A heart has two atria and two ventricles, four rooms.

心脏有两个心房与两个心室，四间房。

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The AbioCor's motor sits between the two ventricles inside a separate chamber filled with silicone fluid.

FORBES: Lonely Heart

This is a new feature, available on some defibrillator-like devices that are now on the market, which is aimed at people with a form of heart condition that causes their two ventricles to beat slightly out of phase with each other.

ECONOMIST: Case history