Cardiac Autonomic Activity, Personality Traits, and Academic Performance in First-Year Medical Students: A Gender-Specific Relation.

Background It is not always the sincere or hardworking or intelligent student that gets the highest grades. Exploring unknown dimensions that may distinguish academic performance in adolescents/youth migrating from a high school study environment to that of a professional school and in a learning environment without parental supervision for the first time remains important. We hypothesized that cardiac autonomic activity influenced by cognitive domain factors and emotions would predict academic success in them. Further, we investigated which of their personality traits related to academic performance. Exploratory gender-based analysis was included. Methods A prospective cohort study measured first-year medical students' resting heart rate, heart rate variability (HRV), and personality traits (from the self-reported NEO Five-Factor Inventory-3). Spearman's correlation coefficient tested the correlation between the year-end final aggregate marks and assessed parameters, including subgroup analysis based on gender. Regression analyses of variables with academic marks were performed in the entire cohort. Results The aggregate marks of 81 volunteering students (Mage = 18.7, SD = 0.8 years; 42 females, 39 males) as a cohort did not correlate with their resting heart rate or HRV indices. Subgroup analysis revealed a positive correlation between marks and high-frequency power (r = 0.33, p= 0.03) and total power (r = 0.37, p= 0.02) of HRV in females. The marks positively correlated with the personality conscientiousness score (r = 0.32, p= 0.04) and extraversion score (r = 0.34, p= 0.03) in females. Multivariable regression analysis in the entire cohort revealed no significant interactions. Conclusion Academic performance was significantly related to cardiac autonomic modulation and personality traits of conscientiousness and extraversion in female but not male first-year medical students. These results indicate a gender-specific difference in the relation between scholastic performance and HRV in adolescents/youth transiting from high school to professional schools and entering a study environment without parental supervision for the first time. Further our data expands the knowledge base of educational psychology among them.

Initial Autonomic Parameters and Subsequent Short-Term Neurological Recovery after Inpatient Rehabilitation, in Traumatic Cervical Spinal Cord Injury Patients.

BACKGROUND: It is unknown whether assessment of autonomic pathway integrity in newly injured traumatic cervical spinal cord injury (SCI) patients contributes to their neurological prognosis. OBJECTIVE: The objective is to investigate the relationship of heart rate variability (HRV) and sympathetic skin response (SSR) at initial evaluation of American Spinal Injury Association Impairment Scale (AIS) A/B tetraplegic patients, with their short-term neurological recovery. METHODS: In this prospective cohort study, short-term HRV indices and SSR to supra-lesional stimuli were computed in 24 acute traumatic cervical AIS A/B SCI patients at admission for rehabilitation. The relationship of these autonomic parameters with motor and sensory score improvement, AIS grade improvement, and time taken for recovery was tested, respectively, with Spearman's correlation coefficient test, Fisher's exact test, and Kaplan-Meier analysis. RESULTS: SSR was present in 11 (45.8%) patients at initial evaluation. After rehabilitation, 5 (20.8%) patients improved from AIS A/B to AIS C (greater recovery), while the rest remained at AIS A/B (lesser recovery). Both AIS improvement and mean time for 'greater' recovery did not associate with the presence/absence of SSR. Further, HRV indices did not correlate with improvement in motor or sensory scores. CONCLUSIONS: Interim neurological recovery was not related to autonomic parameters of short-term HRV indices and SSR in the AIS A/B tetraplegic patients of our study. Interestingly, about half of the patients with clinically complete SCI had evidence of preserved autonomic function. Our data add to the knowledge base of autonomic findings in cervical SCI patients and will promote research relating neurophysiological parameters and recovery.

Sleep and Exercise among Young Doctors in a Tertiary Care Hospital in India: A Pilot Cross-Sectional Study.

Background: Limited information is available on the sleep and propensity for daytime sleepiness in young medical doctors of India. Methods: The 2-week self-reported data surrounding sleep and exercise habits, and the Epworth sleepiness scale (ESS) score obtained from volunteering doctors of a tertiary care hospital in India, were summarized as median (Q1-Q3). Comparisons with Mann-Whitney U test and correlations with Spearman's rank correlation were done. Results: Forty-seven doctors (28 [26-33] years, 16 males) reported a total sleep duration (TSD) of 6.3 (6-6.7) hours, sleep latency of 9 (5.1-15.8) minutes, and ESS score of 8 (5-10). The number of days (out of 14) when the subjective feeling of 'refreshed', 'somewhat refreshed', and 'fatigued' was experienced was respectively 6 (2-9), 5 (3-8), and 1 (0-4). Junior-level doctors experienced more days of 'fatigue' than senior-level doctors (3 [0-4.3], 0 [0-0]; p = 0.002). Doctors who did not exercise reported greater days of fatigue than those who exercised (2 [0-4.8], 0 [0-2]; p = 0.047). Conclusions: The young doctors of our study slept less than the recommended amount of 7 hours by the American Academy of Sleep Medicine. Their short sleep latency and normal propensity for daytime sleepiness, though encouraging, may be an effect of insufficient sleep and mentally alerting daytime schedule respectively. Notably, we found a positive association between exercise habits and subjective restoration following sleep in our study population. The sleep requirements and sleep structure among Indians are yet to be established. Our findings add to the data on sleep in the Indian context.

Intra-class Correlation among Heart Rate Variability analysis softwares across different physiological postures.

Heart rate variability (HRV) is a simple technique which helps to assess the alterations in cardiac autonomic activity in healthy and diseased individuals. It is performed in various research centers using different hardwares and softwares. Hence, HRV reports generated from these centers cannot be compared unless their HRV data acquisition systems and the HRV analysis softwares correlate or agree with each other. In this study, Intra-class correlation coefficient test was done to see the extent of correlation among three HRV analysis softwares used by researchers in India, namely, (1). Kubios HRV version 2.0, Department of Physics, University of Kuopio, Finland, (2). HRV soft 1.1 Version, Autonomic Function Laboratory, Department of Physiology, All India Institute Of Medical Sciences (AIIMS), New Delhi and (3). Nevrokard aHRV 12.0.0. (Medistar Inc., Slovenia). Following standard guidelines, five minutes ECG data was acquired from twenty six healthy volunteers in supine, sitting and standing positions. The R-R intervals were computed from the ECG data and was subjected to short-term HRV analysis using the above three softwares. Statistical analysis revealed a highly significantly (p<0.001) perfect positive correlation (ICC values > 0.8) among the three softwares for both time domain and frequency domain parameters in the three different positions. Hence, it may be proposed that the interpretation of short-term HRV reports generated by the three softwares, across laboratories, can be equated.

Influence of deep breathing exercise on spontaneous respiratory rate and heart rate variability: a randomised controlled trial in healthy subjects.

Studies show that yogic type of breathing exercises reduces the spontaneous respiratory rate. However, there are no conclusive studies on the effects of breathing exercise on heart rate variability. We investigated the effects of non-yogic breathing exercise on respiratory rate and heart rate variability. Healthy subjects (21-33 years, both genders) were randomized into the intervention group (n=18), which performed daily deep breathing exercise at 6 breaths/min (0.1 Hz) for one month, and a control group (n=18) which did not perform any breathing exercise. Baseline respiratory rate and short-term heart rate variability indices were assessed in both groups. Reassessment was done after one month and the change in the parameters from baseline was computed for each group. Comparison of the absolute changes [median (inter-quartile ranges)] of the parameters between the intervention and control group showed a significant difference in the spontaneous respiratory rate [intervention group -2.50 (-4.00, -1.00), control group 0.00 (-1.00, 1.00), cycles/min, P<0.001], mean arterial pressure [intervention group -0.67 (-6.67, 1.33), control group 0.67 (0.00, 6.67), mmHg, (P<0.05)], high frequency power [intervention group 278.50 (17.00, 496.00), control group -1.00 (-341.00, 196.00), ms2 P<0.05] and sum of low and high frequency powers [intervention group 512.00 (-73.00, 999.00), control group 51.00 (-449.00, 324.00), ms2, P<0.05]. Neither the mean of the RR intervals nor the parameters reflecting sympatho-vagal balance were significantly different across the groups. In conclusion, the changes produced by simple deep slow breathing exercise in the respiratory rate and cardiac autonomic modulation of the intervention group were significant, when compared to the changes in the control group. Thus practice of deep slow breathing exercise improves heart rate variability in healthy subjects, without altering their cardiac autonomic balance. These findings have implications in the use of deep breathing exercises to improve cardiac autonomic control in subjects known to have reduced heart rate variability.

Improving the effectiveness of physiology record books as a learning tool for first-year medical students in India.

In compliance with the Medical Council of India, preclinical medical students maintain a record of their laboratory work in physiology. The physiology record books also contain a set of questions to be answered by the students. Faculty members and students had indicated that responding to these questions did not serve the intended purpose of being an effective learning tool. The purpose of this study was to obtain the views of the medical students and faculty members at our institution concerning the usefulness of responding to the questions and to gather suggestions for possible improvement. Data were collected through focus groups and questionnaires to first-year medical students and faculty members in physiology and were analyzed using qualitative and quantitative methods. The students and faculty members viewed the physiology record books as a potentially useful learning aid, but lack of time led the students to write the answers without understanding the topic rather than generating their own responses to the questions. Faculty members and students recommended that the students should write the responses to the questions on site during the practical classes, using relevant on-site resources and interacting with faculty members. The findings of the present study may be of value to other medical colleges in India and outside India with modifications based on their specific needs to improve the effectiveness of physiology record books as a learning tool.

Short-term heart rate variability measures in students during examinations.

BACKGROUND: Heart rate variability measures are reported to be altered in patients with various diseases, implying related abnormality of cardiac autonomic function. Could associated anxiety-induced mental stress, invariably present in all patients, contribute to these alterations? To address this question, we compared heart rate variability parameters computed from students during university examinations, a known cause of mental stress, with those computed during holidays when students are mentally relaxed. We felt that the changes in heart rate variability, if any, could be attributed to mental stress alone. METHODS: We compared short-term heart rate variability parameters computed from 5-minute electrocardiogram recordings during supine rest in 18 healthy students, along with recordings of respiratory rate and blood pressure, during university examinations and holidays. RESULTS: The mean of all the RR intervals was significantly lower, while the mean arterial pressure was significantly higher at the time of examinations. Measures of total variability, namely standard deviation of the normal-to-normal RR intervals and total spectral power, were significantly reduced during examinations. Low frequency normalized units (LF nu), high frequency (HF) nu and the LF/HF ratio were not significantly different. CONCLUSION: The decreased mean RR interval indicates an overall increase in heart rate or cardiac sympatho-excitation during examinations. This is associated with a decrease in total heart rate variability at the time of mental stress. None of the parameters indicative of the ratio of the extent of modulation of cardiac sympathetic to parasympathetic activity were different. These findings may be useful when interpreting measures of heart rate variability in patients.

Attitude of medical students towards Early Clinical Exposure in learning endocrine physiology.

BACKGROUND: Different teaching-learning methods have been used in teaching endocrine physiology for the medical students, so as to increase their interest and enhance their learning. This paper describes the pros and cons of the various approaches used to reinforce didactic instruction in endocrine physiology and goes on to describe the value of adding an Early Clinical Exposure program (ECE) to didactic instruction in endocrine physiology, as well as student reactions to it as an alternative approach. DISCUSSION: Various methods have been used to reinforce didactic instruction in endocrine physiology such as case-stimulated learning, problem-based learning, patient-centred learning and multiple-format sessions. We devised a teaching-learning intervention in endocrine physiology, which comprised of traditional didactic lectures, supplemented with an ECE program consisting of case based lectures and a hospital visit to see patients. A focus group discussion was conducted with the medical students and, based on the themes that emerged from it, a questionnaire was developed and administered to further enquire into the attitude of all the students towards ECE in learning endocrine physiology. The students in their feedback commented that ECE increased their interest for the subject and motivated them to read more. They also felt that ECE enhanced their understanding of endocrine physiology, enabled them to remember the subject better, contributed to their knowledge of the subject and also helped them to integrate their knowledge. Many students said that ECE increased their sensitivity toward patient problems and needs. They expressed a desire and a need for ECE to be continued in teaching endocrine physiology for future groups of students and also be extended for teaching other systems as well. The majority of the students (96.4%) in their feedback gave an overall rating of the program as good to excellent on a 5 point Likert scale. SUMMARY: The ECE program was introduced as an alternative approach to reinforce didactic instruction in endocrine physiology for the first year medical students. The study demonstrated that students clearly enjoyed the experience and perceived that it was valuable. This method could potentially be used for other basic science topics as well.

Sensory input from the moving hand influences saccadic eye movements during reading.

Reading involves saccadic eye movements. Measured reading time and the number of mistakes made while reading reflect the speed and accuracy of the saccades in target localization, if all other factors influencing these parameters are kept constant. The observed phenomenon that reading a book is easier when it is held in an individual's hand than when it is not, especially when movement of the reading text occurs while travelling in a vehicle, raises the question of the role of sensory input from the moving arms in guiding saccades in the direction in which the text is moved. To address this question, 12 healthy subjects (6 males and 6 females), aged 19-21 years took part in this study where reading time and the number of mistakes made while reading a non-moving standardized printed text was noted. Similar printed texts were read by the subjects while mechanically moving them at different fixed speeds in the horizontal plane, with and without the subject's arms moving with the text. At each speed, the reading time recorded when the subject's arms moved with the text was significantly lesser than when they did not (P<0.05). The number of mistakes made were significantly more when not moving the arms than when moving them with the text, at higher speed of text movement (P<0.05). The results indicate that sensory input from the passively moving arms guided saccades in the direction of movement of the text during reading.

Differential effects of organic calcium-channel blockers on diastolic SR calcium-handling in the frog heart.

1. Gradual loss of sarcoplasmic reticular (SR) calcium during a rest-period is responsible for the rest-induced decay (RID) of force in mammalian myocardium. Effect of verapamil and diltiazem on a similar RID in the frog myocardium suggests a new mechanism of action of these drugs. 2. Strips of frog-ventricle were paced at 0.2 Hz and the rhythm was interrupted by varying rest-periods ranging from 10 to 180 s. In control conditions, the amplitude of the post-rest beat was significantly lower than that of the pre-rest beat for rest-periods more than 40 s (RID). 3. Verapamil and diltiazem (which are organic calcium-channel blockers (OCCB)) changed the pattern of RID in the control solution to a 'rest-induced potentiation' (RIP) in the same preparation while another OCCB nifedipine and the inorganic calcium-channel blocker cadmium did not alter the post-rest phenomenon. 4. We propose that verapamil and diltiazem produce an RIP due to either blockade of SR calcium-leak during rest or enhancement of SR calcium-uptake during rest.