two doses of ttx were tested for antiarrhythmic action : a low dose ( low ttx , 10 micrograms/kg of bolus + infusion of 10 micrograms/kg/hr ) which blocked only neuronal activity , and a high dose ( ttxh , 50 micrograms/kg of bolus + infusion of 50 micrograms/kg/hr ) which also produced signs of ventricular gna blockade in normal hearts .
C0018827
ventricular
C0018787
hearts