Heart rate variability in patients presenting with anginal symptoms in absence of cardiac and other diseases

Objectives: Angina is a symptom of coronary artery disease (CAD). Modulation of cardiac autonomic tone as assessed by heart rate (HR) variability (HRV) is found reduced in patients with CAD; myocardial ischemia, myocardial infarction and some other cardiovascular diseases. Reduced HRV has been found associated with sudden cardiac death in these CAD patients. Several patients present with anginal symptoms clinically in absence of CAD or other diseases. The status of HRV is not much clear in these patients. Thus, we aimed to assess HRV in patients with angina with and without myocardial ischemia and compare it with HRV of healthy subjects of similar age groups and follow-up patients for 1 year for cardiac/health events. Materials and Methods: The study included 61 consecutive male patients clinically presenting with angina and 30 healthy subjects. Based on Thallium-201 myocardial perfusion Single-photon emission computerized tomography (SPECT) imaging, patients were divided into two groups; patients with myocardial perfusion defects (MPD), (n = 33, age 54.91 ± 7.43 years) and patients with no MPD (NMPD), NMPD (n = 28, age 53.04 ± 8.50 years). Short-term HRV was assessed in all patients and subjects in resting supine position following standard protocol. All MPD and 25 NMPD patients could be followed up for 1 year for cardiac/health events. Results: Surprisingly, the NMPD patients showed significantly reduced HRV, Standard deviation of the N-N intervals, The square root of the mean squared differences of successive N-N intervals, Percentage of the number of interval differences of successive N-N intervals greater than >50 ms divided by total number of R-R intervals, low frequency (LF) power, High Frequency (HF) power and total power as compared to both MPD patients and healthy subjects. (Total power [NMPD vs. MPD]: 610.1 [379.9–1072.8] vs. 1508.0 [748.4–2339.4] millisecond squares (ms2 ), P = 0.001), healthy subjects (Total power: 1414.6 [1104.6-2141.5] ms2 , P = 0.001). The markers of sympathetic tone; LF (normalised unit) and LF/HF ratio were higher in NMPD patients as compared to MPD patients resulting in an altered sympathovagal balance. During a 1-year follow-up, sudden death was seen in one MPD patient (3.1%) and two NMPD patients (8%). Conclusion: The NMPD patients showed significantly reduced HRV as compared to both MPD patients and Healthy subjects with an altered sympathovagal balance. Sudden death was also seen in NMPD patients as MPD patients.

Mortality due to mass Hymenoptera attacks: A serious but underrecognized public health problem in a mountainous state of India

Most deaths related to Hymenoptera are a result of immediate hypersensitivity reactions causing anaphylaxis to one or few stings. However, if the patient is exposed to a large quantity of the venom due to mass/multiple stings, massive envenomation can cause death in nonallergic individuals. Thirty-nine cases of acute kidney injury (AKI) who followed mass attacks by Hymenoptera were seen over 15 years, with a reference period between 2003 and 2017. AKI was severe; most (85%) of them required dialysis and one-third died. Mass attacks by Hymenoptera have become a serious public health problem in tropics. There is no antivenom, and treatment in such cases is supportive. Early hospitalization is vital to reduce morbidity and mortality.

Validity of heart rate based nomogram fors estimation of maximum oxygen uptake in Indian population.

Maximal oxygen uptake (VO2max) during a graded maximal exercise test is the objective method to assess cardiorespiratory fitness. Maximal oxygen uptake testing is limited to only a few laboratories as it requires trained personnel and strenuous effort by the subject. At the population level, submaximal tests have been developed to derive VO2max indirectly based on heart rate based nomograms or it can be calculated using anthropometric measures. These heart rate based predicted standards have been developed for western population and are used routinely to predict VO2max in Indian population. In the present study VO2max was directly measured by maximal exercise test using a bicycle ergometer and was compared with VO2max derived by recovery heart rate in Queen’s College step test (QCST) (PVO2max I) and with VO2max derived from Wasserman equation based on anthropometric parameters and age (PVO2max II) in a well defined age group of healthy male adults from New Delhi. The values of directly measured VO2max showed no significant correlation either with the estimated VO2max with QCST or with VO2max predicted by Wasserman equation. Bland and Altman method of approach for limit of agreement between VO2max and PVO2max I or PVO2max II revealed that the limits of agreement between directly measured VO2max and PVO2max I or PVO2max II was large indicating inapplicability of prediction equations of western population in the population under study. Thus it is evident that there is an urgent need to develop nomogram for Indian population, may be even for different ethnic sub-population in the country.

Effect of Chyawanprash and vitamin C on glucose tolerance and lipoprotein profile.

Chyawanprash is an ancient Indian dietary supplement containing vitamin C (34 mg/100 g) derived from amla (Emblica officinalis). In addition, Chyawanprash also contains several other herbal products. The present study was designed to compare the effects of vitamin C with those of Chyawanprash. Ten normal healthy adult male volunteers (age 20-32 years) participated in the 16-week study. They were placed randomly in either the Chyawanprash group (n = 5) or vitamin C group (n = 5). Those in the former received 15 g/d of Chyawanprash while those in the latter received 500 mg/d vitamin C during the first 8 weeks of the study. For the next 8 weeks, no supplement was given. For each individual, an oral glucose tolerance test was performed, and lipoprotein profile in peripheral serum samples was determined at 0 weeks, 4 weeks, 8 weeks, 12 weeks and 16 weeks. In the Chyawanprash group, the 8 weeks Vs 0 weeks value (mean +/- S.D.) respectively for various indices which were significantly different were fasting plasma glucose (100.2 +/- 5.58 mg/dl vs 116.2 +/- 11.6 mg/dl), area under 2-h plasma glucose curve (245.9 +/- 15.13 mg.dl-1.h vs 280.8 +/- 37.09 mg.dl-1.h), HDL cholesterol (53.2 +/- 4.56 mg/dl vs 42.7 +/- 7.17 mg/dl), LDL cholesterol (82.4 +/- 8.80 mg/dl vs 98.26 +/- 12.07 mg/dl), LDL/HDL ratio (1.56 +/- 0.28 vs 2.38 +/- 0.63). In the Vitamin C group, only the LDL/HDL ratio was significantly lower at 8 weeks than at 0 weeks (1.99 +/- 0.44 vs 2.29 +/- 0.43). All the variables that changed significantly were no longer significantly different from the 0 weeks value at 16 weeks. Chyawanprash reduces postprandial glycemia in the oral glucose tolerance test and reduces blood cholesterol level to a significantly greater extent than vitamin C.