sinoatrial node sinoatrial • sinoauricular · · · Info · Definitions · Synonyms · Characters · · sinoatrial node · · Text Common · · Latin · · Scripts 15 · · Length 4 · · Syllables Definitions · · · (noun) a specialized bit of heart tissue that controls the heartbeat. Synonyms: pacemaker, cardiac pacemaker, sinoatrial node, SA node. · · Noun Definition 1 Synonyms · · · pacemaker · · Synonym 1 cardiac pacemaker · · Synonym 2 sa node · · Synonym 3 Characters · · space U+0020 a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074