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Alteration of Human Placental Vascular Tone by Antiarrhythmic Medications In Vitro
Author(s) -
OMAR HATIM A.,
RHODES LARRY A.,
RAMIREZ ROLANDO,
ARSICH JELICA,
EINZIG STANLEY
Publication year - 1996
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.1996.tb00498.x
Subject(s) - medicine , adenosine , contraction (grammar) , quinidine , verapamil , flecainide , fetus , endothelium , pharmacology , anesthesia , endocrinology , cardiology , pregnancy , atrial fibrillation , calcium , biology , genetics
Antiarrhythmic and Placental Vessels. Introduction : Antiarrhythmic medications are commonly used during pregnancy for treatment of maternal or fetal arrhythmias, but little is known about their effect on human placental vascular tone and, consequently, placental blood flow. The objective of this study was to evaluate the tone responses caused by antiarrhythmic medications in human placental vessels from normal term pregnancies in vitro. Methods and Results : Isolated human placental arteries and veins from uncomplicated term pregnancies incubated in Krebs'‐bicarbonate under 5% oxygen/5% carbon dioxide/balance nitrogen (PO 2 35 to 38 torr) were exposed to cumulative doses of quinidine, procainamide, lidocaine, flecainide, propranolol, amiodarone, verapamil, digoxin, and adenosine after submaximal contraction with 5‐hydroxytryptamine. The study was conducted both in the presence and absence of endothelium. The addition of the tested medications caused a significant, dose‐dependent relaxation of human placental arteries and veins except for adenosine, which induced a sustained, dose‐dependent contraction of human placental vessels regardless of the presence or absence of tone. Removal of the endothelium did not alter these responses. Conclusions : Based on these results, the medications tested should have no decremental effect on placental blood flow, with the possible exception of adenosine, which causes significant. dosedependent contraction of human placental vessels in vitro. Should similar contraction be present in vivo, it may have an adverse effect on the fetus when administering adenosine to pregnant women at term or during labor.