The main feature of coronary care is the availability of telemetry or the continuous monitoring of the cardiac rhythm by electrocardiography.
One definition of a hook is a musical or lyrical phrase that stands out and is easily remembered. Definitions typically include some of the following: that a hook is repetitive, attention-grabbing, memorable, easy to dance to, and has commercial potential and lyrics. A hook has been defined as a part of a song, sometimes the title or key lyric line, that keeps recurring.
Old Frisian hok, Middle Dutch hoek, Dutch haak, German Haken hook), from PIE *keg- hook, tooth (cf. Russian kogot claw). For spelling, see hood (n.1). Boxing sense of short, swinging blow with the elbow bent is from 1898. Figurative sense was in Middle English (see hooker). By hook or by crook (late 14c.) probably alludes to tools of professional thieves. Hook, line, and sinker completely is 1838, a metaphor from angling.