the v-a ap is established as an essential link of the tachycardia circuit , as evidenced by : 1 ) retrograde atrial activation of the left atrium ( la ) 60 msec or more before the low and high right atrium during reciprocating tachycardia and during v-a conduction ;
C0039231
tachycardia
C0242514
reciprocating tachycardia