| Abstrakt: |
We have evaluated the acute electrophysiological effects of flosequinan in 18 patients with normal ventricular function. Following intravenous infusion of flosequinan 100 mg over 1 h, mean (SD) systolic blood pressure fell from 131 ± 19 to 120±22mmHg (<0·02) and there was significant shortening of sinus cycle length (732±151 to 575±93 ms, <0·001), AH interval (110±45 to 71±19 ms, <0·01) QRS duration (98±28 to 91±26 ms, <0·02) and QT interval (373±47 to 337±35 ms, <0·001 but no change in sinus node recovery time, intra-atrial conduction time, HV interval or the corrected QT interval. There was a reduction in both anterograde atrioventricular Wenckebach cycle length (299±53 to 259 ±52 ms, <0·01) and retrograde ventriculoatrial Wenckebach cycle length (375 ± 77 to 300 ± 56 ms, <0·01). There was no change in atrial or ventricular effective refractory period (ERP) but atrial functional refractory period (FRP) shortened (233 ± 31 to 212 ± 24 ms, =007) as did ventricular FRP (249 ± 24 to 234 ± 21 ms, <0·01). Patients received an oral dose of flosequinan 50 mg 12 h later. By 24 h, sinus cycle length, QRS duration and the QT interval had all returned towards baseline values, but ventricular ERP had lengthened (199±22 to 215±26 ms, <0·06). Programmed ventricular stimulation did not result in any sustained arrhythmias before or after flosequinan. The observed electrophysiological effects of flosequinan infusion are consistent with reflex sympathetic activation. There was no conclusive evidence for any direct electrophysiological effect or for contraction-excitation feedback. No proarrhythmic effects were observed. [ABSTRACT FROM PUBLISHER] |
