atrial fusion beat

a·tri·al fu·sion beat

a beat that occurs when the atria are activated in part by the sinus impulse and in part by an ectopic or retrograde impulse from A-V junction or ventricle.

atrial fusion beat

n. A pulsation occurring when the atria of the heart are activated partly by a sinus impulse and partly by a retrograde impulse from the atrioventricular node or ventricle.

a·tri·al fu·sion beat

(ā'trē-ăl fyū'zhŭn bēt) A beat that occurs when the atria are activated in part by the sinus impulse and in part by an ectopic or retrograde impulse from A-V junction or ventricle.