Autonomic nerve stimulation reverses ventricular repolarization sequence in rabbit hearts
Autonomic nerve stimulation reverses ventricular repolarization sequence in rabbit hearts
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DOI：
10.1161/01.res.0000264101.06417.33
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发表时间：
2007-04-13
影响因子：
20.1
通讯作者：
Salama, Guy
中科院分区：
文献类型：
--
作者：
Mantravadi, Rajkumar;Gabris, Bethann;Salama, Guy
交感神经活动和空间复极离散度（DOR）已被认为是促进心律失常脆弱性的机制;但没有直接测量自主神经刺激对DOR的影响。在具有完全交感神经和副交感神经支配的Langendorff装置中灌注兔心脏，并进行光学标测以测量左心室的动作电位时程和DOR（心尖-基底）。在窦性心律下，在双侧交感神经刺激（SNS）和右侧和/或左侧迷走神经刺激期间测量DOR，并与异丙肾上腺素（100 nmol/L）或乙酰胆碱（1 μ mol/L）输注期间的DOR进行比较。在窦性心律时，复极化开始于心尖部，并系统地向基底部发展。SNS（10 ~ 15 Hz）使DOR增加29%（从Delta动作电位时程= 17 +/- 0.7到-22 +/- 1.6 ms，n = 6），并在SNS后5 ~ 15 s内逆转DOR，因为复极方向从窦性心律时的心尖->基底转变为基底->心尖。在SNS中断后115 +/- 15秒，DOR翻转回到其窦性心律DOR模式。刺激右侧或左侧迷走神经时，DOR的方向无变化，但刺激双侧迷走神经时，DOR增加，DOR逆转为基底->心尖方向。输注异丙肾上腺素或乙酰胆碱增加DOR，但不改变复极序列的方向。这些研究结果表明，双侧自主活动（SNS或迷走神经刺激）引起可逆的顶点-基底DOR的移位，并且自主效应对心室的空间异质性最有可能归因于心脏基底部的神经支配大于心尖部。
Sympathetic activity and spatial dispersion of repolarization (DOR) have been implicated as mechanisms that promote arrhythmia vulnerability; yet there are no direct measurements of the effects of autonomic nerve stimulation on DOR. Rabbit hearts were perfused in a Langendorff apparatus with full sympathetic and parasympathetic innervation and were optically mapped to measure action potential durations and DOR (apex-base) over the left ventricles. DOR was measured under sinus rhythm, during bilateral sympathetic nerve stimulation (SNS) and right and/or left vagus nerve stimulation and was compared with DOR during isoproterenol (100 nmol/L) or acetylcholine (1 mu mol/L) infusion. In sinus rhythm, repolarization started at the apex and systematically progressed toward the base. SNS (10 to 15 Hz) increased DOR by 29% (from Delta action potential duration = 17 +/- 0.7 to -22 +/- 1.6 ms, n = 6) and reversed DOR as the direction of repolarization from apex -> base in sinus rhythm shifted to base -> apex in 5 to 15 seconds after SNS. DOR flipped back to its sinus rhythm DOR pattern 115 +/- 15 seconds after the interruption of SNS. During right or left vagus nerve stimulation, there was no change in the direction of DOR, but bilateral vagus nerve stimulation increased and reversed DOR to base -> apex direction. Infusion of isoproterenol or acetylcholine increased DOR but did not alter the direction of repolarization sequences. These findings demonstrate that bilateral autonomic activity (SNS or vagus nerve stimulation) cause reversible shifts of apex-base DOR and that the spatial heterogeneities of autonomic effects on the ventricles are most likely attributable to a greater innervation at the base than the apex of the heart.