Preparedness of medical students towards e-learning conducted during COVID-19 lockdown: A cross-sectional descriptive study.

BACKGROUND: COVID-19 lockdown has mandated the medical colleges to start academics using electronic mode. Synchronous e-learning was started by our institute to replicate traditional classes in line with the routine academic schedule. the objective of this study attempted to assess the e-learning readiness of the students of our institute. MATERIALS AND METHODS: A cross-sectional descriptive study was planned using the model proposed by Oketch et al. with local modifications. The questionnaire was designed in Google Forms and mailed to respond using Likert scale. The nonparametric data collected from the total 84 respondents were analyzed for validity and reliability of the questionnaire, mean values to know the readiness (mean = 3.4), and one-step multiple regression to know the predictors. RESULTS: The mean eLR (e-learning readiness) as evaluated from attitudinal readiness (MeanAR = 3.6), culture readiness (MeanCR = 2.3), material and technological readiness (MeanMTR = 3.7), and mental health readiness (MeanMHR = 2.4) is 3.03 (60.6% with n = 84). Multiple regression analysis revealed that all the variables except MHR can significantly predict e-learning readiness linearly (P < 0.05). CONCLUSION: The institute is ready for e-learning in terms of AR and MTR (mean values >3.4). CR and MHR still need a lot of improvisation to make it acceptable for e-learning. The model could explain 54.9% readiness level with CR as the most important predictor. More than 73% (n = 84) of the respondents have acknowledged the present form of online classes to be the best available option in COVID-19 lockdown and most of them are adapted to e-classes in the institute.

Preference for salt contributes to sympathovagal imbalance in the genesis of prehypertension.

BACKGROUND/OBJECTIVES: As salt preference is known to cause hypertension (HTN), the present study was conducted to assess the impact of preference for salt on sympathovagal imbalance in prehypertensives by spectral analysis of heart rate variability (HRV). SUBJECTS/METHODS: Body mass index (BMI), basal heart rate, blood pressure (BP), rate pressure product and spectral indices of HRV such as total power (TP), normalized low frequency power (LFnu), normalized high frequency power (HFnu), ratio of low frequency power to high frequency power (LF-HF ratio), mean heart rate, square root of the mean squared differences of successive normal to normal (NN) intervals, the number of interval differences of successive NN intervals >50 ms (NN50) and the proportion derived by dividing NN50 by the total number of NN intervals were assessed in 555 subjects divided into four groups: Group 1, normotensives no-salt-preference subjects (n=260); Group 2, normotensives salt-preference subjects (n=185); Group 3, prehypertensives no-salt-preference subjects (n=25); and Group 4, prehypertensives salt-preference subjects (n=89). Sympathovagal balance was analyzed and contribution of individual factor to sympathovagal imbalance was assessed by regression analysis. RESULTS: LFnu was significantly increased (P=0.009), whereas TP and HFnu were significantly decreased (P=0.024 and 0.007, respectively) in the salt-preference groups compared with the no-salt-preference groups. LF-HF ratio, the sensitive indicator of sympathovagal balance, was significantly increased (P<0.0001) in salt-preference subjects compared with no-salt-preference subjects. In regression analysis, the link of LF-HF ratio to HTN status was found to be more prominent in the salt-preference group (P=0.000) compared with the no-salt-preference group (P=0.004). BMI had no significant contribution (P=0.818) to LF-HF ratio in salt-preference subjects. CONCLUSIONS: Salt preference is associated with sympathovagal imbalance caused by sympathetic overactivity and vagal withdrawal. Sympathovagal imbalance is more intense in salt-preferring prehypertensives compared with salt-preferring normotensives. Sympathovagal imbalance in salt-preferring subjects is independent of BMI. Thus, salt-preferring subjects should be encouraged to restrict salt intake to maintain their sympathovagal balance and BP homeostasis.

Increased vascular tone due to sympathovagal imbalance in normotensive and prehypertensive offspring of hypertensive parents.

AIM: Prehypertension has recently been observed as a potent cardiovascular risk factor. Though prehypertension has a strong familial predisposition, the pathophysiological mechanisms that cause its progression to prehypertension in normotensive sibling of hypertensive parents have not yet been fully elucidated. Therefore, the present study was conducted in normotensive and prehypertensive sibling by spectral analysis of heart rate variability (HRV) to understand the nature of change in sympathovagal balance (SVB) in this condition. METHODS: Body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), basal heart rate (BHR), blood pressure (BP), rate pressure product (RPP) and spectral indices of HRV were assessed in three groups of subjects: Group I (normotensive offspring of normotensive parents, N.=231); Group II (normotensive offspring of hypertensive parents, N.=113); and Group III (prehypertensives offspring of hypertensive parents, N.=52). SVB was analyzed and correlated with BMI, WHR, BHR, BP and RPP in all the groups. RESULTS: Sympathovagal imbalance (SVI) was observed to be present in both normotensive and prehypertensive sibling of hypertensive parents. In normotensive sibling, SVI was mild in the form of proportionate increase in sympathetic and decreased vagal activity. In prehypertensive sibling, SVI was prominent with more of vagal withdrawal. Though LF-HF ratio, the indicator of SVB was correlated with all parameters in groups II and III, the significance was more with diastolic pressure and WHR. CONCLUSION: It was concluded that vagal inhibition plays a critical role in modulation of SVB for progression into prehypertension in normotensive sibling of hypertensive parents and WHR is a prominent marker of SVI in these subjects.

Assessment of sympathovagal imbalance by spectral analysis of heart rate variability in prehypertensive and hypertensive patients in Indian population.

Though the incidence of hypertension has increased considerably in recent years, the pathophysiologic mechanism that causes progression from stage of prehypertension to hypertension has not been fully elucidated. Therefore, the present study was conducted to assess the sympathovagal imbalance in prehypertensives and hypertensives by spectral analysis of heart rate variability (HRV) to understand the nature of change in autonomic balance in this common dysfunction of mankind. Body mass index (BMI), basal heart rate (BHR), blood pressure (BP), and spectral indices of HRV such as total power (TP), normalized low frequency power (LFnu), normalized high frequency power (HFnu), ratio of low frequency power to high frequency power (LF-HF ratio), mean heart rate (mean RR), square root of the mean squared differences of successive normal to normal intervals (RMSSD), the number of interval differences of successive NN intervals greater than 50 ms (NN50), and the proportion derived by dividing NN50 by the total number of NN intervals (pNN50) were assessed in three groups of subjects: normotensives (n = 32), prehypertensives (n = 28), and hypertensives (n = 31). Sympathovagal balance was analyzed and correlated with BMI, BHR, and BP in all the groups. It was observed that autonomic imbalance in prehypertensives was due to proportionate increased sympathetic activity and vagal inhibition, whereas in hypertensives, vagal withdrawal was more prominent than sympathetic overactivity. The LF-HF ratio, the sensitive indicator of sympathovagal balance, was significantly correlated with BMI, BHR, and BP. It was concluded that vagal inhibition plays an important role in the critical alteration of sympathovagal balance in the development of clinical hypertension in prehypertensive subjects.

Study of sympathovagal imbalance by spectral analysis of heart rate variability in young prehypertensives.

Though prehypertension has recently been considered as a risk factor for cardiovascular accidents, the pathophysiological mechanism that causes the development of prehypertension in normotensive subjects has not been fully elucidated. Therefore, the present study was conducted to assess the sympathovagal imbalance in prehypertensives and normotensives by spectral analysis of heart rate variability (HRV) to understand the nature of change in autonomic balance in this dysfunction. Body mass index (BMI), waist-hip ratio (WHR), basal heart rate (BHR), blood pressure (BP), rate-pressure product (RPP) and spectral indices of HRV such as total power (TP), normalized low frequency power (LFnu), normalized high frequency power (HFnu), ratio of low frequency power to high frequency power (LF-HF ratio), mean heart rate (mean RR), square root of the mean squared differences of successive normal to normal intervals; (RMSSD), the number of interval differences of successive NN intervals greater than 50 ms (NN50) and the proportion derived by dividing NN50 by the total number of NN intervals (pNN50) were assessed in two groups of young subjects: normotensives (n=68) and prehypertensives (n=66). Sympathovagal balance (SVB) was analyzed and correlated with BMI, WHR, BHR, BP and RPP in both the groups. It was observed that autonomic imbalance in prehypertensives was due to increase in both sympathetic activity and vagal inhibition. LF-HF ratio, the sensitive indicator of SVB was significantly correlated with BMI, WHR, BHR, BP and RPP in prehypertensive subjects. It was concluded that vagal inhibition might be important in the critical alteration of sympathovagal balance in the development of prehypertension in young normotensive subjects.

Spectral analysis of heart rate variability (HRV) may predict the future development of essential hypertension.

Presently, essential hypertension (EH) is among the most common morbid disorders of mankind. The fundamental pathophysiology of EH is sympathetic overactivity. It has been observed that the people having common risk factors for hypertension such as obesity, insulin resistance and stress generally have increased sympathetic activity. Therefore, it is presumed that patients suffering from EH develop some degree of increased sympathetic activity much before they clinically develop hypertension. Spectral analysis of heart rate variability (HRV) has been demonstrated to accurately assess change in sympathovagal balance (autonomic activity) even when the alteration is in its minimal form. Therefore, in the present paper we hypothesize that spectral analysis of HRV could be utilized for early prediction of EH. We also suggest that the predictive knowledge of sympathovagal imbalance in the development of EH should be employed in elucidating the mechanisms for prevention of this dysfunction.

Sympathovagal imbalance in thyroid dysfunctions in females: correlation with thyroid profile, heart rate and blood pressure.

The aim of the study was to investigate the role of spectral analysis of heart rate variability (HRV) for assessing the type and degree of sympathovagal imbalance (SVI) and their link to cardiovascular morbidities in thyroid dysfunctions. Forty-five female subjects (15 control subjects and freshly diagnosed untreated 15 hypothyroid and 15 hyperthyroid patients) were recruited for the study. Thyroid profile, body mass index (BMI), basal heart rate (BHR), blood pressure (BP) and spectral indices of HRV (TP, LFnu, HFnu and LF-HF ratio, mean RR, SDNN and RMSSD) were assessed in all the three groups. LF-HF ratio was correlated with thyroid profile, BMI, BHR and BP. SVI was more prominent in hyperthyroid (P < 0.001) compared to hypothyroid (P < 0.05) subjects. LF-HF ratio was correlated with thyroid profile in both hypo and hyperthyroid subjects; but correlation with BHR and BP was significant only in hyperthyroidism. Though the SVI was found to be due to both vagal withdrawal and sympathetic activation, especially in hyperthyroidism, contribution by vagal inhibition was prominent. Vagal inhibition contributes significantly to SVI in thyroid dysfunctions, especially in hyperthyroidism. As the present study indicates poor cardiovascular health due to vagal inhibition in patients suffering from thyroid dysfunctions, attempt should be made to improve vagal tone especially in hyperthyroid subjects to attain a stable sympathovagal and cardiovascular homeostasis.