Kurtoglu Ertugrul
Ertugrul Kurtoglu, MD, Ankara Cad. Ozalper Mah, 44100, Malatya, Turkey;
Acta Dermatovenerol Croat. 2017 Oct;25(3):254.
In their article, Potenza et al. evaluated the influence of etanercept therapy on autonomic cardiovascular regulation in young patients with moderate-to-severe psoriasis without cardiovascular risk factors by measuring the time domain and frequency domain heart rate variability (HRV) parameters from 5-minute electrocardiogram (ECG) recordings (1). The authors used low frequency (LF), high frequency (HF) power, and LF/HF ratio as indices of frequency domain HRV and standard deviation of normal-to-normal intervals (SDNN); the mean root square of the sum of the squares of differences between consecutive R-R intervals (RMSSD) was used as the index of time domain HRV. The authors found that 12-week etanercept therapy resulted in non-significant alterations in LF, HF, LF/HF ratio, SDNN, and RMSSD values. They concluded that treatment with etanercept in patients with moderate-to-severe psoriasis does not affect cardiovascular autonomic regulation and cardiovascular risk. HRV is a well-established, rapid, and noninvasive tool for the evaluation of the modulation of the cardiac autonomic nervous system. HRV may also be a sensitive test for the detection of the cardiotoxicity of some chemotherapeutic agents (2). Methods for quantifying HRV are categorized as time domain and spectral or frequency domain. Traditionally, spectral parameters such as LF, HF, and total power have been analyzed from standard 5-minute ECG segments, whereas most laboratories require at least 18 hours of valid data to measure time domain parameters such as SDNN and RMSSD in a 24-hour recording. In addition, the measurement of LF and HF power components is usually given in absolute values of power (milliseconds squared) or percentage. LF and HF can also be calculated in normalized units, which represent the relative value of each power component in proportion to the total power. The representation of LF and HF in normalized units underlies the controlled and balanced behavior of the two branches of the autonomic nervous system. Moreover, the normalization tends to minimize the effect of the changes in total power on the values of LF and HF components. Thus, unnormalized units should be presented in conjunction with normalized versions of the same variables whenever possible in order to completely describe the distribution of power in spectral components (2).
在他们的文章中，波滕扎等人通过测量5分钟心电图（ECG）记录中的时域和频域心率变异性（HRV）参数，评估了依那西普疗法对无心血管危险因素的中重度银屑病年轻患者自主心血管调节的影响（1）。作者使用低频（LF）、高频（HF）功率以及LF/HF比值作为频域HRV的指标，并用正常到正常间期的标准差（SDNN）；连续R-R间期差值平方和的均方根（RMSSD）用作时域HRV的指标。作者发现，12周的依那西普治疗导致LF、HF、LF/HF比值、SDNN和RMSSD值无显著变化。他们得出结论，中重度银屑病患者接受依那西普治疗不会影响心血管自主调节和心血管风险。HRV是一种成熟、快速且无创的评估心脏自主神经系统调节的工具。HRV也可能是检测某些化疗药物心脏毒性的敏感试验（2）。量化HRV的方法分为时域和频谱或频域。传统上，已从标准的5分钟ECG片段中分析诸如LF、HF和总功率等频谱参数，而大多数实验室需要至少18小时的有效数据来测量24小时记录中的时域参数，如SDNN和RMSSD。此外，LF和HF功率成分的测量通常以功率的绝对值（毫秒平方）或百分比给出。LF和HF也可以用归一化单位计算，归一化单位表示每个功率成分相对于总功率的相对值。LF和HF以归一化单位表示是自主神经系统两个分支受控和平衡行为的基础。此外，归一化倾向于最小化总功率变化对LF和HF成分值的影响。因此，只要有可能，未归一化单位应与相同变量的归一化版本一起呈现，以便完整描述频谱成分中的功率分布（2）。
