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Heart and soul: the feeling body
Published in Anthony Korner, Communicative Exchange, Psychotherapy and the Resonant Self, 2020
The associated physiology reflects these functions: when we inspire there is a temporary gate on vagal influence, functionally meaning a relative preparedness for activation or mobilization; while with expiration there is reinstatement of vagal influence, consistent with relaxation and receptive function (Appelhans & Luecken, 2006). Under non-stressed conditions these influences are small. Vocalization increases the effort of expiration and is associated with a shortened RR interval, but does not, in itself, exert a significant influence on RSA (Kotani et al., 2007). (The RR interval is the interval between successive R waves on electrocardiogram recordings.) This is consistent with vocalization and speech being activities compatible with a sense of social safety. In the context of an emotionally engaged psychotherapy, conversations occur that will, at times, have significant emotional content. This can put participants in the position of experiencing significant mobilization of the ANS and CRA. Indeed, these areas of emotional significance are likely to be important to the process of change (Schore, 2012). For both patient and therapist management of these states is crucial to the outcome of the therapy.
Bioelectric and Biomagnetic Signal Analysis
Published in Arvind Kumar Bansal, Javed Iqbal Khan, S. Kaisar Alam, Introduction to Computational Health Informatics, 2019
Arvind Kumar Bansal, Javed Iqbal Khan, S. Kaisar Alam
The major time-segments that carry meaning in the ECG are RR-interval, PR-interval, QT-interval, QTC-interval (corrected QT-interval) and ST-segment. RR-interval measures the interval of one heartbeat. It is chosen as a standard because R-wave is the tallest and the easiest to detect. PR-interval is the time-interval between the start of a P-wave to the start of the following QRS-complex. PR-segment shows the total time taken for the depolarization in atria until the start of the depolarization of the left-ventricle. Shorter PR-segment shows shorter depolarization in atria, and longer PR interval shows -additional delay in AV junction or conduction-block in the bundle-of-His.
The QT interval
Published in Andrew R Houghton, Making Sense of the ECG, 2019
The most commonly used formula for doing this is Bazett's formula. It is common practice to identify which method has been used to correct the QT interval by adding additional letters to QTc, so for instance the use of Bazett's formula is indicated by QTcB: where QTcB is the corrected QT interval using Bazett's formula, QT is the measured QT interval and RR is the measured RR interval (all measurements in seconds). The RR interval is the time between consecutive R waves, and can be either measured directly from the ECG or calculated by dividing 60 by the patient's heart rate. For example, at a heart rate of 80 beats/min, the RR interval is 0.75 s.
Comprehensive viewpoints on heart rate variability at high altitude
Published in Clinical and Experimental Hypertension, 2023
Jun Hou, Keji Lu, Peiwen Chen, Peng Wang, Jing Li, Jiali Yang, Qing Liu, Qiang Xue, Zhaobing Tang, Haifeng Pei
Obstructive Sleep Apnea Syndrome (OSAS) is a common sleep disorder characterized by interrupted breathing, leading to varying degrees of hypoxia. It causes endothelial dysfunction, autonomic nervous system disorders, increased oxidative stress, and other physiological abnormalities. OSAS is also a significant risk factor for cardiovascular diseases (100,101). Through analyzing multiple clinical records of OSAS patients, Khoo et al. discovered a close relationship between OSAS and cardiovascular autonomic nerves (102). The hypoxic environment at high altitudes undoubtedly exacerbates the occurrence of OSAS. Gammoudi et al. conducted retrospective studies and found a strong correlation between changes in HRV and the severity of OSAS. They observed that the RR interval significantly prolonged in mild and moderate OSAS cases, while the LF/HF ratio was significantly reduced (103). OSAS places an excessive aerobic demand on the body, significantly increasing the incidence and mortality of cardiovascular diseases (106,107).
Resting heart rate predicts cardiac autonomic modulation during passive head-up tilt in subjects without cardiovascular diseases
Published in Scandinavian Cardiovascular Journal, 2022
Jenni K. Koskela, Anna Tahvanainen, Antti J. Tikkakoski, Pauliina Kangas, Marko Uitto, Jari Viik, Mika Kähönen, Jukka Mustonen, Ilkka Pörsti
The relation of HRV to HR is not only physiological but also mathematical, and the relation is not linear [3,16]. HRV is usually calculated from consecutive RR-intervals reciprocal to HR measures. Therefore, when lower and higher initial HR levels are compared, a similar change in HR results in a greater change in RR-interval during lower HR. HRV is usually evaluated by the use of time or frequency domains, both of which provide information about vagal and sympathetic modulation [3]. From the frequency domain parameters, the high frequency (HF) component represents vagal activation and the low frequency (LF) component predominantly represents the sympathetic component of HRV [2]. From the time domain parameters, the square root of mean squared differences of normal to normal RR-intervals (RMSSD) mostly represents vagal influence while the standard deviation of normal to normal RR-intervals (SDNN) is an estimate of total HRV [3]. There are mathematical methods that can be applied to strengthen or weaken the dependence of HRV on HR [17].
Effects of capacitive and resistive electric transfer and hot pack interventions on the autonomic nervous system in young women
Published in Electromagnetic Biology and Medicine, 2022
Haruna Matsushita, Momoko Nagai- Tanima, Tomoki Aoyama, Masatoshi Nakamura
ECG measurements included heart rate (HR) and RR intervals using a Cardiofax Velectrocardiograph (Cardiofax V, Nihon Kohden, Tokyo, Japan). Electrodes were applied only to the upper left and right limbs, and lower limbs for limb induction. The HR and RR intervals were calculated from electrocardiograms over a 3 min period. The RR interval represents heart rate variability, which is regulated by the autonomic nervous system -especially the parasympathetic nervous system (Siennicka et al. 2019). In this study, the coefficient of variation (CV), which is the coefficient of variation of the RR interval, was used as an index of autonomic nervous activity. When parasympathetic nervous activity is dominant (where the body is in a relaxed state), the CV value increases; when sympathetic nervous activity is dominant, the CV value decreases (Park et al. 2018). The average HR and average RR interval over 3 min were used in analyses.