Effect of Steroid Eluting Versus Conventional Electrodes on Propafenone Induced Rise in Chronic Ventricular Pacing Threshold

Abstract

The aim of this study was to evaluate chronic ventricular pacing threshold increase after oral propafenone therapy. Eighty-three patients affected by advanced atrioventricular block and sick sinus syndrome were studied at least 3 months after pacemaker implantation, before and after oral propafenone therapy (450-900 mg/day based on body weight). The patients were subdivided into three groups according to the type of unipolar electrode that was implanted: group I (41 patients) Medtronic CapSure 4003, group II (30 patients) Medtronic Target Tip 4011, and group III (12 patients) Osypka Vy screw-in lead. In all cases a Medtronic unipolar pacemaker was implanted: 30 Minix, 23 Activitrax, 14 Elite, 12 Legend, and 4 Pasys. Propafenone blood level was measured in 75 patients 3-5 hours after propafenone administration. The pacing autothreshold was measured at 0.8 V, 1.6 V, and 2.5 V by reducing pulse width. At the three different outputs before and after propafenone, threshold increments were significantly lower in group I in comparison with group II and group III (propafenone ranging from < 0.001 to < 0.05). No significant difference was found in pacing impedance or in propafenone plasma concentration in the three groups. Strength-duration curves were drawn for each group at baseline and after propafenone administration. Before propafenone, in group I, the knee was markedly shifted to the left and downward as compared to the classic curve, so that the steep part was predominant; in group II and group III this shift was progressively less evident.(ABSTRACT TRUNCATED AT 250 WORDS)

The Electrode‐Tissue Interface: The Revolutionary Role of Steroid‐Elution

“…The chronic long‐term protection provided by steroid‐elution against inappropriate stimulation threshold elevations is neither well understood nor has it been adequately investigated. Steroid‐eluting leads protect against the stimulation threshold‐increasing effects of class 1C antiarrhythmic drugs such as Propafenone . Steroid‐elution may further protect against stimulation threshold elevations in some acute and chronic disorders, which appear to have cardiac involvement such as a summer cold in a child .…”

Effects of coronary artery disease in patients with permanent left bundle branch area pacing: A retrospective study

“…Consequently, while the pacemaker itself may function normally, the capture threshold might elevate, possibly leading to ineffective capture of the myocardium and the induction of depolarization [ 36 , 53 ]. Notably, the effect of AADs on the capture threshold remained controversial due to contradicting reports [ 7 , [54] , [55] , [56] , [57] ]. This study also identified no significant association between AADs and capture threshold, which might be because LBBaP beyond the site of the block and AADs had no impact on the conduction beneath the his-bundle lead.…”

Effects of Rhythm and Rate-Controlling Drugs in Patients With Permanent His-Bundle Pacing

“…Arrhythmias are common in patients with pacemakers and may require management with antiarrhythmic drugs (AADs), which may affect the cardiac conduction system (1)(2)(3). Previous studies (4)(5)(6)(7) have reported that some AADs affect atrial and ventricular pacing threshold and impedance. Others have reported that AADs affect defibrillation thresholds of implantable cardioverter defibrillators (8,9).…”