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ISTRODUCTIONSince our previous report, more than 300 electrocardiograms have been obtained on patients performing vigorous exercise (1). The purpose of this communication is to describe the method in detail, indicate the trend of normal variations, and discuss some of the findings in patients with abnormalities of the cardiovascular system.Prior efforts a t recording electrocardiograms during exercise have been only partially successful, since the resultant tracings have contained artifacts inherent in the system used (2-4). The two major difficulties that have been overcome in recording the electrocardiogram during exercise are skeletal muscle potentials and baseline shifts ( Fig. I ) . Skeletal muscle artifacts have been eliminated by attaching the electrodes to areas of the body which are virtually free of skeletal muscles; baseline shifts can be avoided by proper fixation of the electrodes to the skin. Because of the location of the electrodes, the technic is referred to as the Ear-Ensiform-Precordial (EEP) system.A. Apparatus (Fig. 2) nected to a plug jack.' (Fig. 2b.) within a rubber tube 1 cm. thick and 1 cm. in diameter connected to a plug jack. (Fig. 2c.) TECHNIC 1. Ear-lobe electrode consisting of a square (2 x 2 cm.) of stainless-steel wire mesh con-2. Chest electrodes consisting of a piece (1 cm. in diameter) of stainless-steel wire mesh 3. Electrode compound.* 4. Foam rubber cushions, 2 x 3 x 5 cm. (Fig. 2a.) 5 . Chest straps.B. The EEP method (Fig. 3 ) 1. The electrode is secured to the right ear lobe by adhesive tape and a paper clip. 2. The chest electrodes are filled over the brim with electrode compound and placed over the ensiform process, over the fifth rib in the V-3 position, the sixth rib in the V-5 position, a n d the seventh rib in the V-7 position. Each cup electrode is held in place by a "Band-aid" tape and a foam rubber cushion. The foam rubber cushions are held in place over the electrodes by tightly wound elastic chest straps.3. The cables for the patient are attached as follows: a ) With a four-channel machine (Figs. 4, 5 and 6)-the right arm cable to the right ear electrode; the left arm cable to the ensiform electrode; the left leg cable to the V-7 electrode; precordial cables to V-3 and V-5 .electrodes; ground cable to the right arm. b) With a single channel machine, the attachments are the same except that the left leg cable is attached to the V-5 electrode and the single precordial cable to the V-3 electrode.

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.

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.