the tetracyclic antidepressant drug maprotiline was given intravenously to seven healthy volunteers in order to evaluate its effect on sinus node automaticity , on the atrioventricular conduction system judged from hisbundle electrograms , and on the repolarization of the right atrium and ventricle judged from the refractoriness and monophasic action potential duration .
C0037189
sinus node
C0225844
right atrium