Morady F, Kou W H, Kadish A H, Toivonen L K, Kushner J A, Schmaltz S
Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor.
Am J Cardiol. 1988 Sep 15;62(9):580-4. doi: 10.1016/0002-9149(88)90659-5.
The purpose of this study was to determine whether physiologic doses of epinephrine reverse the electrophysiologic effects of quinidine in patients with an accessory atrioventricular (AV) connection. Eighteen patients with an accessory AV connection who had inducible sustained orthodromic tachycardia underwent an electrophysiologic study in the baseline state and after at least 2 days of treatment with 1.4 to 1.9 g/day of quinidine gluconate. The effects of epinephrine were then determined. Epinephrine infusion rates of 25 and 50 ng/kg/min were used in 9 patients each because these doses of epinephrine previously have been demonstrated to result in elevated plasma epinephrine concentrations in the range that occurs during a variety of stresses in humans. Quinidine prolonged refractoriness in the atrium and accessory AV connection and slowed conduction through the accessory AV connection. These effects were partially or completely reversed by epinephrine. Among 8 patients in whom quinidine resulted in orthodromic tachycardia becoming noninducible or nonsustained, sustained tachycardia became inducible again in 5 patients after infusion of epinephrine. After quinidine, atrial fibrillation was either noninducible or nonsustained in 8 patients; however, sustained atrial fibrillation could be induced in 4 of these patients after infusion of epinephrine. The results of this study demonstrate that the therapeutic effect of quinidine in patients who have an accessory AV connection are often reversed by physiologic increases in circulating epinephrine.
本研究的目的是确定生理剂量的肾上腺素是否能逆转奎尼丁对存在房室旁道的患者的电生理效应。18例存在房室旁道且可诱发持续性顺向型心动过速的患者，在基线状态下以及接受1.4至1.9 g/天葡萄糖酸奎尼丁治疗至少2天后接受了电生理研究。然后确定肾上腺素的效应。9例患者使用25 ng/kg/min的肾上腺素输注速率，另外9例患者使用50 ng/kg/min的输注速率，因为先前已证明这些剂量的肾上腺素可使血浆肾上腺素浓度升高至人类在各种应激状态下出现的范围内。奎尼丁延长了心房和房室旁道的不应期，并减慢了通过房室旁道的传导。这些效应被肾上腺素部分或完全逆转。在8例奎尼丁使顺向型心动过速变为不可诱发或非持续性的患者中，5例在输注肾上腺素后持续性心动过速再次变为可诱发。使用奎尼丁后，8例患者的心房颤动不可诱发或非持续性；然而，其中4例患者在输注肾上腺素后可诱发持续性心房颤动。本研究结果表明，循环中肾上腺素的生理性增加常常会逆转奎尼丁对存在房室旁道患者的治疗效果。
