Faculty Collaboration Database

Reactive oxygen species contribute to contractile dysfunction following rapid ventricular pacing in dogs. Int J Cardiol 2002 May;83(2):125-31

Date

05/15/2002

Pubmed ID

12007684

DOI

10.1016/s0167-5273(02)00030-x

Scopus ID

2-s2.0-0036253101 (requires institutional sign-in at Scopus site)   11 Citations

Abstract

BACKGROUND: Ventricular tachyarrhythmias may produce subsequent myocardial dysfunction through the formation of oxygen-derived free radicals. We tested the hypothesis that the antioxidant N-acetylcysteine enhances recovery of contractile function after rapid ventricular pacing.

METHODS: Barbiturate-anesthetized dogs were instrumented for measurement of systemic and coronary hemodynamics and subendocardial segment shortening (%SS). All dogs were subjected to 3 h of rapid ventricular pacing (230 beats/min) followed by a 2 h recovery period. In three groups (n=8 each), dogs received intravenous 0.9% saline or N-acetylcysteine (50 or 150 mg/kg over 60 min) in a random manner before pacing.

RESULTS: N-acetylcysteine did not affect systemic and coronary hemodynamics or alter regional myocardial contractility. Rapid ventricular pacing significantly (P<0.05) increased rate-pressure product and left ventricular end-diastolic pressure and decreased +dP/dt(max). Rapid ventricular pacing produced equivalent degrees of contractile dysfunction in dogs receiving saline or N-acetylcysteine (e.g. %SS of 14.7+/-1.8 to -3.8+/-2.7% before and during pacing in saline-pretreated dogs). Dogs receiving the 150 mg/kg dose of N-acetylcysteine demonstrated greater recovery of contractile function than those pretreated with saline or the 50 mg/kg dose (e.g. %SS of 12.3+/-1.7% compared to 7.0+/-2.0% 2 h after pacing in dogs receiving saline). No differences in systemic and coronary hemodynamics were observed between groups during recovery from pacing.

CONCLUSIONS: The results indicate that the N-acetylcysteine enhances recovery of contractile function after rapid ventricular pacing independent of alterations in systemic and coronary hemodynamics and imply that reactive oxygen species are an important component of the contractile dysfunction following rapid pacing in vivo.

Author List

Gare M, Mraovic B, Kehl F, Kersten JR, Warltier DC, Pagel PS

MESH terms used to index this publication - Major topics in bold

Acetylcysteine
Analysis of Variance
Animals
Cardiac Pacing, Artificial
Disease Models, Animal
Dogs
Female
Free Radical Scavengers
Heart Function Tests
Hemodynamics
Male
Myocardial Contraction
Myocardial Stunning
Probability
Random Allocation
Reactive Oxygen Species
Reference Values
Stroke Volume
Ventricular Dysfunction, Left