Effects of polidocanol as a constituent of a venous sclerosing agent on cardiac electrical activity. Studies on the isolated perfused heart and papillary muscle of the guinea pig and on the isolated sinus node of the rabbit.
The effects of a frequently used sclerosing agent (Sotravarix 6%, main constituent polidocanol 60 mg/ml = 0.1 mol/l) on the electrical activity of the isolated perfused guinea pig heart and on transmembrane potential of isolated papillary muscle and sinus node were studied. Application of the sclerosing agent in a dilution of 1:40,000 (corresponding to polidocanol 2.6 x 10(-6) mol/l) caused a significant decrease in frequency (-27%) and (at constant frequency) a significant delay of the atrioventricular as well as of the intraventricular conduction (+105% or + 210%, resp. n = 4). These effects were only slightly reversible in a 30 min wash-out period. In the isolated papillary muscle, the sclerosing agent (dilution 1:10,000; polidocanol 1 x 10(-5) mol/l) decreased the maximum rate of rise of the action potential and shortened its duration, both by about 10%. In the isolated sinus node the same dilution decreased the spontaneous rate by about 8% mainly by reducing the diastolic depolarization rate (-18%). The effects of the sclerosing agent are attributable to the influence of polidocanol and consist in a blockade of the fast sodium channels (local anesthesia) and in additional inhibitory effects on calcium and/or potassium conductance.
Oexle
B
B
Physiologisches Institut, University of Freiburg/Brsg. Fed. Rep. of Germany.
Weirich
J
J
Haverkampf
K
K
Antoni
H
H
D000200:Action Potentials; D000818:Animals; D004562:Electrocardiography; D005260:Female; D006168:Guinea Pigs; D006329:Heart Conduction System / Q000187:drug effects*; D008297:Male; D008564:Membrane Potentials; D008839:Microelectrodes; D010210:Papillary Muscles / Q000187:drug effects; D000077423:Polidocanol; D011092:Polyethylene Glycols / Q000494:pharmacology*; D011817:Rabbits; D012597:Sclerosing Solutions / Q000494:pharmacology*; D012849:Sinoatrial Node / Q000187:drug effects*
D012597:Sclerosing Solutions; D000077423:Polidocanol; D011092:Polyethylene Glycols