title: Does reducing unnecessary right ventricular pacing improve sympathetic activity and innervation of heart in sinus node disease patients? MVP and SafeR study.
abstract: Ventricular desynchronization imposed by ventricular pacing causes regional disturbances of adrenergic innervation in the left ventricular myocardium and increases the risk of heart failure and atrial fibrillation (AF) in patients with sinus node disease (SND). As a result, decreased iodine-123 metaiodobenzylguanidine (I-(123 )MIBG) uptake occurs in patients with an implanted permanent pacemaker. Fourteen SND patients with an implanted pacemaker equipped with an algorithm for reducing unnecessary right ventricular pacing (RURVP) were enrolled. Pacemakers were programmed to RURVP mode for the first 12 weeks, and then reprogrammed to DDD for the last 12 weeks. At the end of each mode, data on cumulative percent ventricular pacing (%Vp), atrial high rate episodes (%AHR), I-(123 )MIBG myocardial scintigraphy, brain natriuretic peptide (BNP), human atrial natriuretic peptide (hANP), and myocardial damage indices typified by troponin T and C-reactive protein (CRP) were collected. %Vp was lower in RURVP than in DDD (0.2% versus 95.7%, P = 0.00098). BNP, hANP, troponin T, and CRP did not differ significantly between the pacing modes. However, I-(123 )MIBG findings of patients with full ventricular pacing in DDD improved in RURVP. In contrast, among patients without full ventricular pacing in DDD, their I-(123 )MIBG findings did not differ significantly between the pacing modes. In SND patients with normal cardiac function and intact atrioventricular conduction, the reduction of %Vp in RURVP was due to the reduction of ineffective pacing and fusion pacing in DDD. Therefore, these 2 types of pacing do not affect cardiac pump function.
authors.affiliation: Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, Kanagawa, Japan.
authors.forename: Mihoko
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kimura
authors.forename: Junya
authors.initials: J
authors.lastname: Hosoda
authors.forename: Katsumi
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Kohei
authors.initials: K
authors.lastname: Matsushita
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Umemura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001283:Atrioventricular Node / Q000294:innervation* / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012804:Sick Sinus Syndrome / Q000503:physiopathology / Q000628:therapy*; D012849:Sinoatrial Node / Q000294:innervation* / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D016896:Treatment Outcome