Itt írjon a(z) HeartRateVariability-ról/ről

Introduction

As stated by (Almeida-Santos MA, et al), Heart rate variability (HRV) is a parameter that measures time variations of sinus rhythm, reflecting regulatory effects of the nervous system and humoral factors on the sinoatrial node (Almeida-Santos MA, et al). Measuring HRV is a dependable way to evaluate differences in the autonomic nervous system (Peng RC, Yan WR et al). When we discuss heart rate variability, we must include the standard deviation of normal-to-normal RR intervals (SDNN) and also the root mean square of successive differences (RMSSD). The (SDNN) describes both the sympathetic and vagal activity, while the (RMSSD) describes mostly the sympathetic activity (Yi HT, Hsieh YC et al). There are numerous methods of measuring heart rate variability. One of the most common methods is using electrocardiography (ECG). 24 hour ECG recordings are completed when the test subject goes about their regular life. These recordings are very useful for analysing the risk of pathological problems and for assessing autonomic dysfunction.

Effects of disease on heart rate variability

The effects that a disease may have on heart rate variability, or the irregularities of heart rate variability which informs us of an underlining physiological problem has been demonstrated by many different experiments and has proved useful in aiding diagnoses and treatment of diseases. Two diseases that affect heart rate variability are: Gastric Cancer (GC), and Diabetes mellitus (type one). (Michael Kessler and Javdat Karimov).Gastric Cancer is a frequent type of gastrointestinal cancer that has an extremely high mortality rate among common cancers (Park JY, von Karsa L et al). The study investigated changes of SDNN and RMSSD on patients with Gastric Cancer in order to scrutinize the predicting role of HRV in relation to the disease. The result of the experiment demonstrated that as the gastric cancer developed, the SDNN and the RMSSD decreased (Songjie Hu, Jie Lou et al). This decrease in HRV has been noted with patients that have mid to late stage tumours, this is a result of damage to the autonomic nerves (Walsh D, Nelson KA et al). Clinical Investigations have proven that the HRV can be used as an insight of the extremity of different types of cancers (De Couck M, Gidron Y). The study analysed, measured different tumour sites and stages. It was discovered that in Gastric Cancer patients, there was a relationship between tumour size and HRV, although when the tumour reached above 2 centimetres, the decrease in HRV was inhibited. The experiment also discovered that the deterioration of the vagal nerves had a direct effect on the spread of the tumour in gastric cancer patients. In conclusion, patients with gastric cancer have a decreased heart rate variability in comparison to the healthy control patients. Diabetes Mellitus (DM) type one is a disease that causes the degradation of Beta cells, leading to an insulin deficiency which in turn decreases glucose uptake (World Health Organization, Sociedade Brasileira de Diabetes). Investigations on heart rate variability and type one DM is scarce in comparison to type two DM. Diabetes mellitus (DM) may be accompanied by autonomic nervous system (ANS) dysfunction. Measuring heart rate variability may detect this ANS dysfunction (Malpas SC, Maling TJ,Boulton AJ, Vinik AI et al). Using heart rate variability measurements, it has been noted that patients with diabetes mellitus type one have decreased heart rate variability and also a parasympathetic decrease along with an increase in sympathetic activity in comparison to healthy patients (Guzik P, Piskorski J et al, Javorka M, Javorková J et al, Chessa M, Butera G,Kardelen F, Akçurin G et al). Measuring heart rate variability has been shown to prove useful in prognostics and diagnostics by recognising autonomic changes and changes in cardiac rhythm (Khandoker AH, Jelinek HF et al, Pivatelli FC, Santos MA et al). Bearing this in mind, the study investigated aimed to demonstrate that heart rate variability indices have a predictive role in type one diabetic patients by identifying autonomic and cardiac rhythm changes (Anne Kastelianne França da Silva et al). The study concluded that patients with type one Diabetes Mellitus had irregular HRV, in comparison to the healthy control patients. These changes in HRV are suggestive of an irregular autonomic nervous system which can lead to an increased mortality rate (Schmid H). As an overall review, this study’s findings indicate that the use of HRV indices can be an inexpensive and easy tool to detect diabetes mellitus type one, and to allow clinical assessments of ANS dysfunction, which may be able to decrease mortality rate in patients with type one Diabetes mellitus (Zochodne DW).