Altered Heart Rate Variability During Rest in Schizophrenia: A State Marker.

BACKGROUND: Autonomic nervous system (ANS) imbalance has been reported in a number of psychiatric disorders such as depression, schizophrenia, panic disorder, etc. Autonomic dysfunction in schizophrenia has been associated with the symptoms and manifestation of psychosis. Heart rate variability (HRV) as a tool has been widely used to assess ANS activity and the effect of disease on the sympathovagal balance. Therefore, in the present study, HRV derived from electrocardiogram (ECG) lead II at rest was investigated in order to understand the changes in frequency domain measures in patients with schizophrenia and their first-degree relatives compared to healthy controls. METHODS: Twenty-five patients with schizophrenia, 24 first-degree relatives of patients, and 24 healthy controls (Diagnostic and Statistical Manual of Mental Disorders (DSM)-5; 18-45 years) were included in the study. HRV of the subjects was measured after five minutes of rest. ECG lead II was recorded for five minutes and HRV was analysed in the frequency domain: low frequency (LF), high frequency (HF), total power, and LF/HF ratio. HRV parameters and heart rate were statistically analysed for group comparisons using general linear model multivariate analysis. RESULTS: Patients had significantly higher minimum heart rate and lower HF (normalized units (nu)) compared to their first-degree relatives. A trend was observed in HF (nu) with the lowest in patients followed by healthy controls and first-degree relatives and LF/HF ratio was the highest in patients followed by healthy controls and first-degree relatives, although not statistically significant. No significant difference was found between first-degree relatives and healthy controls. CONCLUSION: The alteration of HRV in schizophrenia could be attributed to reduction in vagal tone and sympathetic dominance, which in turn could serve as state markers of schizophrenia.

Short-Term Effect of Spiritual Music on Heart Rate Variability in Medical Students: A Single-Group Experimental Study.

BACKGROUND: There are ancient texts and modern studies alluding to the therapeutic benefits obtained from listening to music. Studies have shown that chanting "OM" has a relaxing effect by causing parasympathetic dominance, limbic deactivation, and decreasing the brain's dopamine levels. This research aims to study the effect of listening to OM chanting on the cardiovascular system and heart rate variability and its possible use as a stress buster among medical students. MATERIALS AND METHODS: Fifty medical undergraduates were selected for the study. After a 20-minute relaxation, a lead 2 electrocardiogram (EKG) was recorded for 10 minutes. Their blood pressure (BP) and heart rate were measured. The subjects were then made to listen to OM chanting for 20 minutes, immediately after which their BP and heart rate were measured. This was followed by another 10-minute lead 2 EKG. The EKGs recorded were then used to calculate the standard deviation in N-N interval (SDNN), total power, high-frequency power, and low-frequency power. RESULTS: The study reported a significant decrease in blood pressure and heart rate and a significant increase in SDNN and total power. There was also an insignificant increase in low frequency and an insignificant decrease in high frequency. CONCLUSION:  This study provides insight into the importance of spiritual music therapy in the maintenance of mental as well as cardiovascular health among medical students.

Applicability of Concept Maps to Assess Higher Order Thinking in the Context of Indian Medical Education: An Analytical Study in the Subject of Physiology.

Introduction: Concept mapping is a multidimensional tool that has been put to little use in India. We designed this study to check its applicability for assessing higher-order thinking in the subject of Physiology. Methods: This interventional analytical study was carried out among 65 students of Phase I of MBBS in the year 2021. The students were sensitized to the technique and were given a practice session. On a pre-informed date, an assessment of a topic taught to them was done using concept mapping and a multiple-choice question (MCQ) based test. Feedback on the technique was taken from the students. The statistical tests used were test of normality - Kolmogorov-Smirnov Test, significance of association - Wilcoxon Signed Rank test, correlation - Spearman's correlation, and agreement - Bland Altman Analysis. The discrimination index was calculated for both concept mapping and MCQ based tests, separately. Percentages were calculated for feedback questionnaire items. The data were analysed using Microsoft Excel (2019) and an online calculator. P-values <0.05 were considered statistically significant. Results: Students scored more in concept mapping. There was a significant difference in the scores of the students on the two tests (Wilcoxon Signed-Rank test, Z=-2.66, p=0.008) and a weakly positive non-significant correlation between them (Spearman's correlation coefficient, rs=0.07 p=0.60). Bland Altman's Analysis showed agreement in the scores of the students in the two tests. The mean score of the students in the two tests increased, so did the difference in the scores in the two tests. The discrimination index of concept mapping (0.28) was higher than that of the MCQ-based test (0.18). Most of the students agreed on the advantages of concept mapping in the feedback. Conclusion: The assessment result of concept mapping is better than that of MCQ-based test and it may be included as a teaching-learning and assessment strategy in the context of Indian medical education in the subject of Physiology.

Effect of Resonance Breathing on Heart Rate Variability and Cognitive Functions in Young Adults: A Randomised Controlled Study.

INTRODUCTION: Heart rate variability (HRV) is an important physiological biomarker of wellbeing, mood, and adaptation, and hence improvements in HRV signify improved health, mood, and adaptation to stress. Resonance breathing has consistently been shown to increase HRV, mood, and adaptability. The study investigated the effects of four-week training of resonance breathing in young adults on HRV, stress, and cognition functions. METHODS: The randomized controlled study was conducted on young men (18-30 years) after obtaining Institutional Ethics Committee approval and written informed consent from the participants. Participants were randomly divided into two groups: the control group and the resonance breathing (RB) group. Baseline parameters, along with heart rate variability, trail tests for cognition, and perceived stress level, were assessed in both groups. After undergoing four weeks of training, the intervention group practiced deep breathing at the resonance frequency for 20 minutes per day for four weeks, whereas the control group did not. All parameters were recorded again after four weeks of resonance breathing. RESULTS: No difference was observed in the HRV parameters in the control group at baseline and four weeks after the baseline recording (p>0.05). In the intervention group, there was a significant improvement in the HRV parameters, the standard deviation of the normal-to-normal interval (SDNN), the proportion derived by dividing NN50 by the total number of NN intervals (pNN50), and total power, after practicing four weeks of resonance breathing (p<0.05). A significant difference in these parameters was also observed in the control and intervention groups after four weeks (p<0.05). There was a significant improvement in the Trails A and B test performance in the intervention group after practicing for four weeks of RB. Similarly, the perceived stress score decreased significantly in the RB group in comparison to its baseline value as well as the control group value.  Conclusion: Increased parasympathetic and decreased sympathetic activity were observed after practicing 20 minutes of resonance frequency breathing every day for four weeks. It also improved cognition and reduced perceived stress levels among young adults. It is recommended that young adults should practice deep breathing at the resonance frequency for a few minutes every day. This would allay anxiety and stress, improve their cognitive performance, and also reduce their cardiovascular morbidity.

Effect of controlled deep breathing on psychomotor and higher mental functions in normal individuals.

OBJECTIVE: The present study was conducted to assess the effect of controlled deep breathing on psychomotor and higher mental functions. METHODS: 100 normal healthy subjects (52 females and 48 males, age range - 18 to 25 years) participated in the study. Each subject acted as his or her own control. Six weeks course of controlled deep breathing i.e. 5 seconds of maximal inhalation followed by 5 seconds of maximal exhalation, once a day for ten minutes, six days a week was arranged. (i) Letter cancellation test (ii) Rapid fire arithmetic deviation test and (iii) Playing card test were conducted before and after six weeks of controlled deep breathing practice for evaluating psychomotor and higher mental functions. RESULTS: No significant gender difference was observed on comparing baseline readings between female and male subjects. After six weeks of controlled deep breathing practice letter cancellation test time significantly reduced (P<0.001), rapid fire arithmetic deviation test and playing card test scores (P<0.001) significantly improved. Letter cancellation test score didn't show improvement. CONCLUSION: The results suggest that a short, simple breathing practice can be helpful in improving cognitive processes.

Effect of Sub Maximal Dynamic and Static Exercises on QTc interval in Healthy Young Men.

INTRODUCTION: The QTc interval depends largely on cardiac repolarization since the duration of cardiac depolarization is fairly constant in the normal heart. QTc at rest as well as during exercise has many clinical implications. In this study, we have compared the relative effects of dynamic and static exercise on QTc. AIM: To measure QTc interval in young men at rest and also assess how it is further modulated by submaximal dynamic and static exercises. MATERIALS AND METHODS: This observational study was conducted in the Department of Physiology on 30 non-obese young men randomly selected from the students of our institute after obtaining the consent and institutional ethical clearance. Continuous blood pressure monitoring and ECG recording was done in the subjects. Baseline (pre-exercise), post submaximal dynamic (Harvard's step test) and post submaximal static exercise (hand-grip exercise) recordings of ABP and ECG were taken for analysis. The measured QT interval was corrected for heart rate using the formula of Bazett et al., {QTc=QT/RR(1/2)}.Statistical analysis was done using Graph pad Prism 5 software (California, USA). The baseline and post-exercise data were compared using paired t-test. A p<0.05 was taken to be statistical significant. RESULTS: There were statistically significant increases in HR, SBP, DBP and QTc interval after dynamic exercise in comparison to the baseline values (p<0.05). Significant increase in HR (p<0.05) with no significant change in QTc and other cardiovascular parameters were recorded following static exercise (p>0.05). CONCLUSION: Significant increase in QTc interval was observed after dynamic exercise, however, no change in QTc was observed following static exercise, and hence we conclude that static exercises may not be useful in assessing the cardiovascular status of an individual or in predicting cardiovascular events.