A wide application of ATP to abolish reciprocal paroxysmal tachycardia
is limited by frequent and adverse effects of the drug. Experients on
49 rats have revealed that successive intravenous injections of verap
amil and ATP have a more pronounced and prolonged action than the drug
s alone. It is assumed that decreased pacemaker activity of sinus noda
l cells and reduced atrioventricular conduction (''binodal dysfunction
'') are as a result of drug calcium channel block in the cellular memb
ranes of myocytes. Potentiation of the pharmacological action of the d
rugs in question may be used in the clinical setting to lower an ATP d
ose and to reduce the incidence of adverse effects.