Premium
Increased sensitivity of the heart to catecholamine‐induced arrhythmias following guanethidine
Author(s) -
Muelheims Gerhard H.,
Entrup Richard W.,
Paiewonsky Donald,
Mierzwiak Donald S.
Publication year - 1965
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1002/cpt196566757
Subject(s) - guanethidine , norepinephrine , heart rate , medicine , blood pressure , baroreceptor , catecholamine , anesthesia , endocrinology , cardiology , stimulation , dopamine
Guanethidine was administered orally to normotensive subjects and the responsiveness of the cardiovascular system to a norepinephrine infusion in increasing concentrations was examined. After guanethidine the infusion of norepinephrine resulted in a higher mean arterial blood pressure and a lower heart rate; cardiac arrhythmias appeared after lower doses of norepinephrine with greater frequency and occasionally were of a type having more serious implication. The almost exclusive development of A‐V nodal beats and A‐V nodal rhythm before as well as after guanethidine suggests the importance of vagal activity reflexly produced by stimulation of the sinoaortic baroreceptors through the rise in blood pressure. However, a direct effect of guanethidine sensitizing the myocardium to norepinephrine cannot be ruled out. It seems advisable to administer norepinephrine to patients receiving guanethidine with even greater caution than usual.