老年房颤应用地高辛后出现长R-R间隔的临床意义

Clinical implication of long R - R intervals by digoxin treatment of atrial fibrillation in the elderly

目的:探讨老年持续性房颤患者应用地高辛后出现长R—R间隔的临床意义。方法:在服用地高辛的84例老年房颤患者中,测定血浆地高辛浓度,观察长R—R间隔的发生率,以及其在接受同步直流电转复后的房室传导情况。结果:小剂量地高辛有效减慢持续性房颤的心室率,长R—R间隔的发生率为44％,在同步直流电转复后无1例存在Ⅱ度房室传导阻滞。结论:小剂量地高辛可安全、有效地控制老年房颤患者的心室率,出现较长的 R—R 间隔可能与地高辛拟迷走效应引起的房室交界区隐匿性传导增加有关,不应作为洋地黄过量和停药的指标。

Objective: To investigate the influence of digoxin treatment on R - R intervals in the elderly with continuous atrial fibrillation. Method: Concentration of plasma digoxin, frequency of long R - R intervals and pattern of atrioventricular conduction in response to synchronized cardioversion were observed in 84 cases after administration of digoxin. Results: Small doses of digoxin could decrease the ventricular rate and long R- R intervals appeared in 37 cases, accounting for 44 percent. No cases were with second-degree atrioventricular block after the cardioversion. Conclusion: Small doses of digoxin showed the safe and effective control over the ventricular rate. The long R- R intervals may be associated with increased atrioventricular junctional concealed conduction induced by digoxin' s parasympathominetic effect rather than its overdose use. So it would not be considered as an indicator of the withdrawal of the drug.