Synergistic action of atrial dilation and sodium channel blockade on conduction in rabbit atria

被引:34
作者
Eijsbouts, SCM
Houben, RPM
Blaauw, Y
Schotten, U
Allessie, MA
机构
[1] Maastricht Univ, Cardiovasc Res Inst Maastricht, Dept Physiol, NL-6200 MD Maastricht, Netherlands
[2] Bakken Res Ctr, Maastricht, Netherlands
关键词
electrophysiology; atrial dilation; antiarrhythmic drugs; conduction block; anisotropy;
D O I
10.1046/j.1540-8167.2004.04326.x
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
Synergism Between Atrial Dilation and Flecainide. Introduction: The aim of this study was to investigate the interaction of atrial dilation and blockade of the rapid sodium channel on atrial conduction and degree of anisotropy. Methods and Results: The right atrium was acutely dilated by increasing intra-atrial pressure from 2 to 9 cm H2O in 14 isolated rabbit hearts. A rectangular mapping array of 240 electrodes (spatial resolution 0.5 mm) was positioned on the free wall of the right atrium during pacing from four different directions at intervals of 240 and 140 msec. In nondilated atria, 0.5 and 1.0 mg/L of the use-dependent I-Na blocker flecainide prolonged the total conduction time under the mapping electrode by 15% to 75%. In dilated atria, flecainide depressed conduction by 24% to 89% (P < 0.05). The incidence of intra-atrial conduction block increased from 0.6%-0.8% to 3.3%-7.2% in nondilated atria and from 3.9%-4.6% to 13%-21% in dilated atria (P < 0.05). The direction of activation relative to the crista terminalis and major pectinate muscles was of major importance for occurrence of conduction block. During rapid pacing, the degree of anisotropy in conduction increased by the combination of atrial dilation and flecainide (1.0 mg/L) from 1.7 +/- 0.1 to 2.2 +/- 0.4 (P < 0.05). The effects of dilation and flecainide on conduction were clearly synergistic. The effect of flecainide on the atrial refractory period also was enhanced by atrial dilation. Conclusion: In dilated atria, blockade of the rapid sodium channels caused a higher degree of local conduction delay and intra-atrial conduction block than in nondilated atria.
引用
收藏
页码:1453 / 1461
页数:9
相关论文
共 30 条
[21]   ATRIAL ENLARGEMENT AS A CONSEQUENCE OF ATRIAL-FIBRILLATION - A PROSPECTIVE ECHOCARDIOGRAPHIC STUDY [J].
SANFILIPPO, AJ ;
ABASCAL, VM ;
SHEEHAN, M ;
OERTEL, LB ;
HARRIGAN, P ;
HUGHES, RA ;
WEYMAN, AE .
CIRCULATION, 1990, 82 (03) :792-797
[22]   Unequal atrial stretch in dogs increases dispersion of refractoriness conducive to developing atrial fibrillation [J].
Satoh, T ;
Zipes, DP .
JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, 1996, 7 (09) :833-842
[23]  
Shaw RM, 1997, CIRC RES, V81, P727
[24]   PROPAGATING DEPOLARIZATION IN ANISOTROPIC HUMAN AND CANINE CARDIAC-MUSCLE - APPARENT DIRECTIONAL DIFFERENCES IN MEMBRANE CAPACITANCE - A SIMPLIFIED MODEL FOR SELECTIVE DIRECTIONAL EFFECTS OF MODIFYING THE SODIUM CONDUCTANCE ON VMAX, TAU-FOOT, AND THE PROPAGATION SAFETY FACTOR [J].
SPACH, MS ;
DOLBER, PC ;
HEIDLAGE, JF ;
KOOTSEY, JM ;
JOHNSON, EA .
CIRCULATION RESEARCH, 1987, 60 (02) :206-219
[25]   INFLUENCE OF THE PASSIVE ANISOTROPIC PROPERTIES ON DIRECTIONAL DIFFERENCES IN PROPAGATION FOLLOWING MODIFICATION OF THE SODIUM CONDUCTANCE IN HUMAN ATRIAL MUSCLE - A MODEL OF REENTRY BASED ON ANISOTROPIC DISCONTINUOUS PROPAGATION [J].
SPACH, MS ;
DOLBER, PC ;
HEIDLAGE, JF .
CIRCULATION RESEARCH, 1988, 62 (04) :811-832
[26]   THE FUNCTIONAL-ROLE OF STRUCTURAL COMPLEXITIES IN THE PROPAGATION OF DEPOLARIZATION IN THE ATRIUM OF THE DOG - CARDIAC CONDUCTION DISTURBANCES DUE TO DISCONTINUITIES OF EFFECTIVE AXIAL RESISTIVITY [J].
SPACH, MS ;
MILLER, WT ;
DOLBER, PC ;
KOOTSEY, JM ;
SOMMER, JR ;
MOSHER, CE .
CIRCULATION RESEARCH, 1982, 50 (02) :175-191
[27]   THE DISCONTINUOUS NATURE OF PROPAGATION IN NORMAL CANINE CARDIAC-MUSCLE - EVIDENCE FOR RECURRENT DISCONTINUITIES OF INTRACELLULAR RESISTANCE THAT AFFECT THE MEMBRANE CURRENTS [J].
SPACH, MS ;
MILLER, WT ;
GESELOWITZ, DB ;
BARR, RC ;
KOOTSEY, JM ;
JOHNSON, EA .
CIRCULATION RESEARCH, 1981, 48 (01) :39-54
[28]   THE VALUE OF CLASS-IC ANTIARRHYTHMIC DRUGS FOR ACUTE CONVERSION OF PAROXYSMAL ATRIAL-FIBRILLATION OR FLUTTER TO SINUS RHYTHM [J].
SUTTORP, MJ ;
KINGMA, JH ;
JESSURUN, ER ;
LIEAHUEN, L ;
VANHEMEL, NM ;
LIE, KI .
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY, 1990, 16 (07) :1722-1727
[29]   ECHOCARDIOGRAPHIC PREDICTORS OF NONRHEUMATIC ATRIAL-FIBRILLATION - THE FRAMINGHAM-HEART-STUDY [J].
VAZIRI, SM ;
LARSON, MG ;
BENJAMIN, EJ ;
LEVY, D .
CIRCULATION, 1994, 89 (02) :724-730
[30]   Widening of the excitable gap during pharmacological cardioversion of atrial fibrillation in the goat -: Effects of cibenzoline, hydroquinidine, flecainide, and d-sotalol [J].
Wijffels, MCEF ;
Dorland, R ;
Mast, F ;
Allessie, MA .
CIRCULATION, 2000, 102 (02) :260-267