Hluchý J, Milovský V, Pavlovic M, Uhliariková H, Makovíni M
Department of Internal Medicine, National Cancer Institute, Bratislava, Czechoslovakia.
Int J Cardiol. 1991 Dec;33(3):357-64. doi: 10.1016/0167-5273(91)90064-v.
In 17 controls, and 17 patients with sinus nodal dysfunction, an electrophysiologic study was made of sinus nodal function and atrioventricular nodal conduction in the basal state. The study was then repeated in all patients after atropine. The heart rate, mean sinus cycle length, variations of sinus cycle length, sinus node recovery times, sinuatrial conduction time, AH interval, and atrioventricular nodal Wenckebach threshold were significantly different in patients from those of controls. All these parameters changed significantly in patients after atropine, and were comparable to those of controls except for the atrioventricular nodal Wenckebach threshold. Atropine failed to increase the heart rate beyond 90 beats per minute in 10 of 17 patients (sensitivity of 59%) or by at least 30% above the resting heart rate only in 4 of them (sensitivity of 24%). The variations of sinus cycle length, and their standardized value, could detect sinus nodal dysfunction with sensitivities of 59 and 47%, respectively. From our results, we conclude that there is parasympathetic overactivity in patients with sinus nodal dysfunction. Because of their very low sensitivities, the atropine test and variations of sinus cycle length were not useful in identifying sinus nodal dysfunction noninvasively. The normal response of the heart rate to atropine does not exclude sinus nodal dysfunction, but atropine may help to differentiate abnormalities intrinsic and extrinsic to the sinus node during the electrophysiologic study.
对17名对照者和17名窦房结功能障碍患者在基础状态下进行了窦房结功能和房室结传导的电生理研究。然后对所有患者在使用阿托品后重复该研究。患者的心率、平均窦房结周期长度、窦房结周期长度变化、窦房结恢复时间、窦房传导时间、AH间期和房室结文氏阈值与对照者有显著差异。使用阿托品后，所有这些参数在患者中均有显著变化，除房室结文氏阈值外，与对照者相当。17名患者中有10名（敏感性为59%）使用阿托品后心率未能超过90次/分钟，只有4名患者（敏感性为24%）心率比静息心率至少增加30%。窦房结周期长度变化及其标准化值检测窦房结功能障碍的敏感性分别为59%和47%。根据我们的结果，我们得出结论，窦房结功能障碍患者存在副交感神经活动亢进。由于其敏感性非常低，阿托品试验和窦房结周期长度变化在无创识别窦房结功能障碍方面并无用处。心率对阿托品的正常反应并不能排除窦房结功能障碍，但在电生理研究中，阿托品可能有助于区分窦房结内在和外在的异常。
