/ Thesaurus / S Synonyms of sinoatrial node Find synonyms for: Noun1. pacemaker, cardiac pacemaker, sinoatrial node, SA node, cardiac muscle, heart muscleusage: a specialized bit of heart tissue that controls the heartbeatWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: acerbity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language