ARRHYTHMIA FORMATION DURING DIGOXIN-QUINIDINE THERAPY

同时接受地高辛和奎尼丁治疗的患者注意到 血浆地高辛浓度显著升高。这个 这些患者易发生毒性反应的程度 地高辛的症状存在争议。然而，因为 心律失常的形成是其潜在的严重并发症。 药物治疗，这个问题应该得到解决。目的 这项研究是为了确定是否有增加的或 发病率或敏感度来确定是否有增加 无论是发病率还是易感性 地高辛-奎尼丁给药期间心律失常，并揭示 心律失常发生的可能电生理机制。在……里面 第一系列实验，8只狗，以前是 植入3对心脏电极，将接受地高辛 0.0125毫克/公斤/天，连续12天，然后是地高辛加奎尼丁 15 mg/kg，每日2次，连续5天。接下来，狗将被分成两部分 分成两组，分别接受奎尼丁或(D)地高辛治疗 是正常剂量的两倍，连续7天。在每个养生法之后，狗 将监测2个小时的心电变化。那他们就会 麻醉并检查房室结传导的变化 以及心室兴奋性的变化。在第二个系列中 实验中，冠状动脉左前降支将 20只麻醉犬进行结扎。狗狗会康复的 接受地高辛或地高辛加奎尼丁。6日以后 当天，狗将被麻醉，并接受程序化的心脏 起搏以测试心律失常的敏感性。在第三个系列中 实验中，用动物心脏的浦肯野纤维切片 在上述研究中将泰罗德溶液灌流。 地高辛威尔灌流过程中的微电极检查 确定诱发后电位所需的时间和/或 心搏停止。研究结果应该揭示：(A)如果心律失常 是一个潜在的问题，在同步地高辛-奎尼丁 治疗，(B)在奎尼丁存在的情况下血清地高辛水平 反映地高辛的治疗和毒性潜力，(C)如果 奎尼丁和地高辛的作用是相加的。这样的信息 对于正在治疗患者的临床医生来说是有价值的 这些药物或其他提高地高辛水平的药物。

Patients receiving digoxin and quinidine concurrently are noted to have a significant increase in plasma digoxin concentrations. The extent to which these patients are susceptible to develop toxicity symptoms of digoxin is controversial. However, because arrhythmia formation is a potentially serious complication of this drug therapy, this problem should be addressed. The purpose of this study is to determine if there is an increase in either the incidence or the susceptibility to determine if there is an increase in either the incidence or the susceptibility to develop arrhythmias during digoxin-quinidine administration, and to reveal possible electrophysiologic mechanisms for arrhythmogenesis. In the first series of experiments, 8 dogs that were previously implanted with 3 pair of cardiac electrodes, will receive digoxin 0.0125 mg./kg/day for 12 days followed by digoxin plus quinidine 15 mg/kg twice daily for 5 days. Next, the dogs will be divided into two groups and receive either quinidine or (d) digoxin at twice the normal dose for 7 days. After each regimen, the dogs will be monitored for 2 hours for changes in ECG. Then they will be anesthetized and tested for changes in AV nodal conduction and changes in ventricular excitability. In the second series of experiments, the Left Anterior Descending Coronary Artery will be ligated in 20 anesthetized dogs. The dogs will recover and receive either digoxin or digoxin plus quinidine. After the 6th day, dogs will be anesthetized, and undergo programmed cardiac pacing to test for arrhythmia susceptibility. In the third series of experiments, Purkinje fiber sections from hearts of animals used in the above studies will be perfused in Tyrodes solution. Microelectrode examination during perfusion with digoxin will determine the time necessary to induce afterpotentials and/or asystole. The results of the study should reveal (a) if arrhythmias are a potential problem during concurrent digoxin-quinidine therapy, (b) if serum digoxin levels in the presence of quinidine reflect the therapeutic and toxic potential of digoxin, (c) if the actions of quinidine and digoxin are additive. Such information would be valuable to clinicians who are treating patients with these drugs or other drugs that raise digoxin levels.