That (supposedly) strengthens the heart. Cf. cardiac, adj. 2. Obsolete.

Of a medicinal agent: having the (supposed) property of strengthening the heart (cf. cordial, adj. 1a); having a physiological effect on the heart…

that strengthens or improves the function of the heart; spec. that increases the force of contraction of the heart.

In various scientific uses; esp. beta receptor (Physiology), one of two categories of adrenergic receptor on organs innervated by sympathetic…