Grimm W, Wirths A, Hoffmann J, Menz V, Maisch B
Department of Cardiology, Hospital of the Philipps-University of Marburg, Germany.
Pacing Clin Electrophysiol. 1998 Nov;21(11 Pt 2):2411-5. doi: 10.1111/j.1540-8159.1998.tb01192.x.
The relation between heart rate variability (HRV) and outcome of head-up tilt testing (HUT) in patients with neurally mediated syncope (NMS) was studied in 30 patients with presumed NMS (33 +/- 13 years) and in 11 age-matched controls. After 15 minutes of baseline supine observation, patients were tilted to 60 degrees for 45 minutes or until syncope occurred. HRV parameters included RR intervals, standard deviation of normal-to-normal RR intervals (SDNN), and root mean square successive differences (RMSSD). HRV analysis was performed during 5-minute intervals in the supine position immediately after onset of HUT and before syncope or after 30-35 minutes of tilt in patients without syncope. Syncope occurred after a mean tilt duration of 32 minutes in 14 (47%) of 30 patients with presumed NMS, whereas all controls had an uneventful HUT. In the supine position, RR intervals and RMSSD were comparable among HUT-positive patients, HUT-negative patients, and controls (RR intervals: 799 +/- 92, 854 +/- 137, and 818 +/- 128 ms, P = NS; RMSSD: 43 +/- 40, 36 +/- 34, and 53 +/- 42 ms, P = NS). Baseline SDNN was also comparable in HUT-positive patients versus HUT-negative patients with presumed NMS (50 +/- 26 vs 52 +/- 20 ms, P = NS). Within 5 minutes preceding syncope or after 30-35 minutes of tilt, RR intervals and RMSSD were shorter in HUT-positive patients compared to HUT-negative patients, or to controls (RR intervals: 606 +/- 86 vs 710 +/- 117 and 739 +/- 123 ms, P < 0.05; RMSSD: 12 +/- 5 vs 23 +/- 19 and 40 +/- 32 ms, P < 0.05). Thus, HRV analysis in the baseline supine position was not a predictor of HUT outcome in patients with suspected NMS. Syncope during HUT seemed to be preceded by increased sympathetic activity manifested by an increase in heart rate and by a decreased parasympathetic tone manifested by a decrease in RMSSD measured for 5 minutes before the event, in comparison with HUT-negative patients and with controls.
对30例疑似神经介导性晕厥（NMS）患者（33±13岁）和11例年龄匹配的对照者进行研究，以探讨心率变异性（HRV）与神经介导性晕厥患者直立倾斜试验（HUT）结果之间的关系。在基线仰卧位观察15分钟后，将患者倾斜至60度并保持45分钟，或直至发生晕厥。HRV参数包括RR间期、正常RR间期标准差（SDNN）和逐次差值均方根（RMSSD）。在HUT开始后立即仰卧位以及晕厥前或无晕厥患者倾斜30 - 35分钟期间，每隔5分钟进行一次HRV分析。30例疑似NMS患者中有14例（47%）在平均倾斜32分钟后发生晕厥，而所有对照者的HUT均顺利完成。在仰卧位时，HUT阳性患者、HUT阴性患者和对照者的RR间期和RMSSD相当（RR间期：799±92、854±137和818±128毫秒，P =无显著性差异；RMSSD：43±40、36±34和53±42毫秒，P =无显著性差异）。疑似NMS的HUT阳性患者与HUT阴性患者的基线SDNN也相当（50±26对52±20毫秒，P =无显著性差异）。在晕厥前5分钟内或倾斜30 - 35分钟后，与HUT阴性患者或对照者相比，HUT阳性患者的RR间期和RMSSD较短（RR间期：606±86对710±117和739±123毫秒，P < 0.05；RMSSD：12±5对23±19和40±32毫秒，P < 0.05）。因此，在基线仰卧位进行HRV分析并不能预测疑似NMS患者的HUT结果。与HUT阴性患者和对照者相比，HUT期间的晕厥似乎在发生前交感神经活动增加，表现为心率加快，副交感神经张力降低，表现为事件前5分钟测量的RMSSD降低。
