This paper deals with the classification of ECG measured from isolated rabbit hearts during the experiment with repeated ischemia. Classification features were calculated using the methods of heart rate variability analysis. The results were statistically evaluated. Heart rate variability parameters were calculated using Kubios HRV, other calculations were performed in MATLAB. Artificial neural network was created to classify the analyzed parameters to specific groups.

This paper deals with HRV analysis, creating segments for this analysis, calculating HRV parameters and their classification for automatic detection of ischemia. First part of the work is dedicated to theoretical describtion of heart anatomy, ECG reading, its processing and methods of HRV analysis. Next part of this work outline the principle of creating segments used for calculation of HRV parameters. Last part of the work indtroduces classification of said parameters with the help of multilayered neural networks and finding their best possible setup based on least classification error and computing time achieved. Calculation of HRV parameters and classification was realized using software Matlab.

Heart rate variability (HRV) is the time variation between adjacent heartbeats. This variation is regulated by the autonomic nervous system (ANS) and its two branches, the sympathetic and parasympathetic nervous system. HRV is considered as an essential clinical tool to estimate the imbalance between the two branches, hence as an indicator of age and cardiac-related events.This thesis focuses on the ECG recordings during nocturnal rest to estimate the influence of HRV in predicting the age decade of healthy individuals. Time and frequency domains, as well as non-linear methods, are explored to extract the HRV features. Three feature-based methods (support vector machine (SVM), random forest, and extreme gradient boosting (XGBoost)) were employed, and the overall test accuracy achieved in capturing the actual class was relatively low (lower than 30%). SVM classifier had the lowest performance, while random forests and XGBoost performed slightly better. Although the difference is negligible, the random forest had the highest test accuracy, approximately 29%, using a subset of ten optimal HRV features. Furthermore, to validate the findings, the original dataset was shuffled and used as a test set and compared the performance to other related research outputs.

The present study evaluated the utility of heart rhythm coherence (HRC) feedback to reduce the reported pain intensity of patients enrolled in a multimodal pain management program. Participants were recruited and assigned to a usual treatment group (UT) or a heart rhythm coherence feedback group (UT+HRC). It was hypothesized that UT+HRC participants who achieved heart rhythm coherence would report a reduction of pain intensity, as measured by the McGill Pain Inventory. For those whose pain intensity decreased, it was also expected that their self reported levels of depression as measured by the Beck Depression Inventory-Second Edition and state anger as measured by the State Trait Anger Inventory would decrease. It is also hypothesized that with a reduction in pain levels, anger, and depression, blood pressure would also decrease among those who had high blood pressure prior to the intervention. Multivariate analyses of variance (MANOVA) were used to investigate the relationship between treatment condition, coherence status and pain levels. A series of independent t-tests were utilized to investigate the change in pain, depression, and state anger from baseline to posttest, followed by Pearson product moment correlation coefficients on difference scores to understand the relationship between the outcome variables for Hypothesis 2. Standard multiple regression analyses were computed using difference scores to determine if the outcome measures were significant predictors of systolic blood pressure and diastolic blood pressure. Results indicated a failure to reject the null with regard to hypothesis one. No relationship between treatment assignment, coherence status or pain levels were found. Hypothesis 2 was partially supported. Although there was a positive significant relationship between depression and anger when utilizing difference scores, these affective measures were not related to difference scores on either pain measure. In regard to Hypothesis 3, there was also a failure to reject the null. None of the outcome measures utilized in this study emerged as being significantly related to changes in systolic or diastolic blood pressure. Limitations of the study and implications for future research are offered.

Anorexia nervosa (MA) is serious psychiatric disease associated with significant mortality. One of the main causes of mortality in these patients is cardiac complications. In 2003 - 2010 we examined 30 patients with established diagnosis of MA. Routinely used nutritional parameters are normal even in severe malnutrition in MA patients and we can ́t use them to diagnose or monitor nutritional status. Therefore we evaluated plasma aminoacids levels to detect minor changes of protein metabolism. According to our results we found mild hyperaminoacidemia and significant elevation of Gly/Val and Phe/Tyr ratio. In the second part of our research we performed non invasive examination s in risky patients with AN to consider possible cardiac complications. Results of ECG and echocardiography confirm results of the previous published studies. Original finding is significant decrease in flow mediated dilatation of brachial artery and its normalization after realimentation. We found also in ambulatory blood pressure monitoring significant decrease in blood pressure during the active period which was the consequence of changes in the heart rate variability. Decrease of the blood pressure in patients with AN in standing position was associated with increase of HF power in supine position and particularly with the lack of...

Physiological indicators like heart rate (HR) and its variability (HRV) from ECG (electrocardiograms), and frontal lobe alpha power asymmetry (AA) and frontoparietal connectivity from EEG (electroencephalograms), can elucidate the role of the nervous system and other visceral organs and their effects on behavioral measures of cognitive and emotional self-regulation. Knowledge of the intergenerational transmission of cardiac and cerebral physiology can provide insight as to the developmental patterns of the organization and stabilization of these physiological processes in children and their mothers. The current study addresses a key question: Is there a developmental shift from 3-9 years of age in the overall pattern of EEG and ECG similarity between children and their mothers? The hypothesis was that there would be increasing child-mother similarity with age. EEG and ECG physiology was examined during a resting-state baseline period, during completion of cognitive tasks, and as baseline-to-task changes in EEG AA and frontoparietal coherence, and ECG HR and HRV in children and their mothers. A socioeconomically diverse longitudinal sample of 171 mothers with their children at ages 3, 6, and 9 years completed questionnaires and laboratory visits. Results indicated that there was some evidence to suggest the presence of mother-child similarity. Twenty of the seventy-two estimated intraclass correlations were significant. Furthermore, of the 20 significant correlations overall, none were present at child age 3 years, 6 were significant at child age 6 years, and 14 were significant at child age 9 years. Thus, overall, there was evidence that by age 6 years, child-mother similarity in physiological indicators of SR had begun to emerge. Additionally, consistent with the study hypothesis, there was some evidence of a pattern of increasing similarity for certain physiological indicators. Of the 72 estimated age-difference Fisher tests for increasing similarity, 17 were significant and in the hypothesized direction. The greatest number were seen during the task condition for ages 6 and 9, and particularly for the frontoparietal EEG variables. Findings are interpreted in light of social learning and behavioral genetics theories.

Thesis advisor: Elizabeth Kensinger / Individuals with social anxiety disorder (SAD) tend to have emotional memory biases in the encoding and retrieval of social memories. Research has shown reduced heart rate variability (HRV) in clinical populations suffering from anxiety, including social anxiety. Heightened sympathetic activation—as measured by the electrodermal activity (EDA)—has also been associated with anxiety disorders. The aim of the present study was to examine the relation between HRV, social anxiety, and re-experiencing of emotional autobiographical memories. 44 healthy young adults were recruited from the Boston College campus through SONA. Participants were given an online survey that instructed them to retrieve 40 specific events from the past in response to 40 socially relevant cues. For each event, participants were instructed to provide a brief narrative, make several ratings for the event (on a scale from 1-7), and indicate the specific emotions they experienced both at the time of retrieval and of the event. Approximately one month after the completion of the memory survey, participants engaged in a 2-hour memory retrieval session while undergoing psychophysiological monitoring (heart rate, skin conductance, and respiration). Following the retrieval task, participants completed self-report questionnaires of social anxiety symptom severity and trait emotion regulation strategy (i.e., tendency to reappraise or suppress emotions). The present study found that positive memories had higher re-experiencing ratings as compared to negative memories. Contrary to the original study hypothesis, however, there was no significant interaction between average re-experiencing (or arousal) ratings of positive or negative social autobiographical memories and SAD likelihood. A nonlinear, cubic relationship was found between one of three metrics of HRV and social anxiety symptom severity. A significant effect was found between skin conductance and SAD likelihood, which was likely driven by an almost significance difference in skin conductance between the SAD unlikely and the SAD very probable groups; these findings provide further insight into the relationship between autonomic nervous system (ANS) functioning and social anxiety. Further, the present results suggest the intriguing possibility that there may be a nonlinear relationship between HRV and severity of social anxiety. Future research with a larger sample size is needed to corroborate these findings. / Thesis (BS) — Boston College, 2018. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Psychology.

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