Heart rate variability in drug-naive patients with panic disorder and major depressive disorder

Power spectral analysis of electrocardiogram (ECG) R-R intervals is useful for the detection of autonomic dysfunction in various clinical disorders. Although both panic disorder (PD) and major depressive disorder (MDD) are known to have effects on the cardiac autonomic nervous system, no previous study has tested this among drug-naive (i.e. no history of treatment) patients with MDD and PD in the same study. The purpose of this study was to compare cardiac autonomic functions among drug-naive patients with MDD and PD and those of healthy controls. Subjects were 17 drug-naive PD patients, 15 drug-naive MDD patients and 15 normal controls. ECGs were recorded under both supine resting and supine deep-breathing conditions (10-12 breaths/min: 0.17-0.20 Hz). We measured the low-frequency power (LF; 0.05-0.15 Hz), which may reflect baroreflex function, the high-frequency power (HF; 0.15-0.40 Hz), which reflects cardiac parasympathetic activity, as well as the LF/HF ratio. As expected, deep breathing induced an increase in HF power and a decrease in the LF/HF ratio in healthy controls. Compared to these controls, however, the MDD group had a lower response to regular deep breathing in LF power and in LF/HF ratio. PD patients showed intermediate results between normal controls and MDD patients. The results indicate that the reactivity to deep breathing revealed diminished cardiac autonomic reactivity in drug-naive MDD patients. (C) 2009 Elsevier Inc. All rights reserved.

心电图（ECG）R - R间期的功率谱分析对于检测各种临床疾病中的自主神经功能障碍是有用的。尽管已知惊恐障碍（PD）和重性抑郁症（MDD）都会对心脏自主神经系统产生影响，但之前没有研究在同一研究中对未用药（即无治疗史）的MDD和PD患者进行过这方面的检测。本研究的目的是比较未用药的MDD患者、PD患者和健康对照者的心脏自主神经功能。研究对象为17名未用药的PD患者、15名未用药的MDD患者和15名正常对照者。在仰卧静息和仰卧深呼吸（10 - 12次/分钟：0.17 - 0.20赫兹）两种条件下记录心电图。我们测量了可能反映压力反射功能的低频功率（LF；0.05 - 0.15赫兹）、反映心脏副交感神经活动的高频功率（HF；0.15 - 0.40赫兹）以及LF/HF比值。正如预期的那样，深呼吸使健康对照者的HF功率增加，LF/HF比值降低。然而，与这些对照者相比，MDD组在LF功率和LF/HF比值方面对规律深呼吸的反应较低。PD患者的结果介于正常对照者和MDD患者之间。结果表明，深呼吸反应性揭示了未用药的MDD患者心脏自主神经反应性降低。（C）2009爱思唯尔公司。保留所有权利。