[Effect of somatostatin on the conduction system of the heart].
Somatostatin (S), a naturally occurring peptide, was first discovered more than 20 years ago. This peptide was later found in many tissues, including human cardiac tissue. High concentration of S was found in the sinus and atrioventricular (AV) nodes. Negative chronotropic activity of S and depressive effects of this substance on AF junction have also been described. The purpose of the present study was to determine the effect of S on the cardiac conduction system in man during antegrade and retrograde conduction. The study group consisted of 12 pts (5 women and 7 men, mean age 43 years). They were subjected to invasive electrophysiologic testing because of sudden unexplained heart palpitations. After measuring all electrophysiologic variables in the control state, each patient was given S (preparation Stilamin, Serono) intravenously with a syringe pump at a dose of 8.5 micrograms/min, for about 30 min. All the electrophysiologic measurements were repeated in the same order, beginning from the 6th min after the start of S injection. S prolonged mean sinus cycle length by 13%, sinoatrial, intraatrial and AV nodal conduction times by 15, 9 and 10%, respectively. Effective refractory periods of the atrium, AV node and right ventricle were prolonged by 7, 8 and 8%, respectively (all p values less than 0.01). Antegrade AV nodal Wenckebach cycle length, as well as retrograde, increased significantly (by 9 and 10% respectively). There were no significant changes of the mean HV interval, corrected QT interval, ventriculoatrial conduction time and corrected sinus node recovery time during S infusion.(ABSTRACT TRUNCATED AT 250 WORDS)
Bubiński
R
R
Kliniki Kardiologii Wojskowej Akademii Medycznej, Lodzi.
Kuś
W
W
Goch
J
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology; D004594:Electrophysiology; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013004:Somatostatin / Q000494:pharmacology*
D013004:Somatostatin
Wpływ somatostatyny na układ bodźcoprzewodzacy serca.