Abstract
Isradipine (PN 200-110) is a new dihydropyridine calcium entry blocker with powerful vasodilating properties. Plasma concentrations obtained after commonly used dosage do not decrease myocardial contractility. However, in vitro studies have demonstrated negative chronotropic action with only minor dromotropic influence. Therefore, the electrophysiologic properties of intravenous isradipine 0.3 μg/kg for 30 minutes in persons with normal sinus and atrioventricular nodal function were investigated. There were no unwanted side effects. Mean blood pressure decreased slightly, but not significantly (107 ± 19 to 100 ± 9 mm Hg). Sinus cycle length decreased from 798 ± 176 to 730 ± 163 msec (p <0.01). The atrioventricular nodal functional refractory period decreased from 418 ± 40 to 399 ± 47 (p <0.05) and the atrial His interval decreased from 95 ± 20 to 91 ± 20 (p <0.01). The His ventricle interval, corrected sinus node recovery time, Wenckebach cycle length, and QRS duration remained unchanged. The QT c was prolonged from 417 ± 39 to 427 ± 40 (p <0.01). It was concluded that isradipine has no depressant effect on normal sinus and atrioventricular node function in humans and is well tolerated. The electrophysiologic effects seem to be the results of enhanced sympathetic tone provoked by peripheral vasodilatation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
