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We occasionally place our bodies under pressure, for example, by playing sports or giving an important presentation at a business meeting. In such situations, most of us have experienced choking, which impairs performance. It has been reported that controlling the heart rate is effective at reducing anxiety, which is one of the causes of choking. Previous studies have proposed a method of reducing choking by undergoing special training for controlling heart rate. Here, we investigated whether a reduction in heart rate after physical activity reduces choking without any special training. Participants bowled under both high-pressure and low-pressure conditions. Before throwing the bowling ball, half of the participants ran on the spot (active condition), whereas the rest of the participants stood instead of running (inactive condition). After controlling for the baseline score, the bowling score in the high-pressure and active condition was significantly better than that in the inactive condition. Additionally, the reduction in heart rate in the active condition was larger than that in the inactive condition. These results suggest that the reduction in heart rate prevented choking without any specific training.

Exercise with HICT methods is not the only effort to prevent cardiovascular disease. The development of science and technology of sports has resulted in the latest innovations and discoveries such as High Intensity Interval Training (HIIT) method that can improve cardiovascular abilities. HIIT is more flexible to do than High Intensity Continous Training (HICT) method. The purpose of this study is to compare exercise with HIIT and HICT method. It is an experimental quasy using 32 swimming athletes who were divided into two groups and given different training to measure VO2max, heart rate recovery, and resting heart rate. Subjects did training for five weeks with a frequency of exercise five times a week. The results show an increase in VO2Max in the HIIT group (22.83%) compared to the continuous group (9.36%) with p

As the number of patients with heart disease increases in Korea, interest in cardiac rehabilitation is increasing. The cardiac rehabilitation exercise requires a certain amount of exercise according to the target heart rate, and monitoring of the medical personnel is required because the pattern of increasing and decreasing heart rate is different according to the person. in this regard, research on controlling the heart rate using a treadmill or ergometer is underway in foreign countries, but there are few studies in Korea. In addition, it is difficult to model and control the heart rate of human body because it has high nonlinearity. In this paper, to overcome this problem, we approximated a 2nd order linear system, modeled it and simulated using a robust controller, SMC. In the future, the experiment will be conducted for the normal people.

This paper focuses on the relationship between blood pressure (BP) and heart rate (HR) during 24 hours in 423 normotensive (NO) and 205 hypertensive (HE) subjects. Although considerable knowledge has been gained about BP and HR signals, their relationship over 24 hours has never been completely described. By using a Holter Blood Pressure Monitor, it was possible to record BP and HR for 24 hours. Systolic, Diastolic and Mean BP in both NO and HE subjects showed four different time intervals presenting well-defined trends The results demonstrated that changes in HR present closely parallel changes in BP with a marked reduction of both signals during nocturnal rest. On the contrary, in the period between 15:30 and 19:30, HR and BP showed an inverse relationship with decreasing heart rate and increasing blood pressure.

AimThe aim of this review was to summarize current knowledge about the scientific findings and potential clinical utility of heart rate variability measures in patients with systemic lupus erythematosus.MethodsPubMed, Embase and Scopus databases were searched for the terms associated with systemic lupus erythematosus and heart rate variability, including controlled vocabulary, when appropriate. Articles published in English and available in full text were considered. Finally, 11 publications were selected, according to the systematic review protocol and were analyzed.ResultsIn general, heart rate variability, measured in the time and frequency domains, was reported to be decreased in patients with systemic lupus erythematosus compared with controls. In some systemic lupus erythematosus studies, heart rate variability was found to correlate with inflammatory markers and albumin levels. A novel heart rate variability measure, heart rate turbulence onset, was shown to be increased, while heart rate turbulence slope was decreased in systemic lupus erythematosus patients. Reports of associations of changes in heart rate variability parameters with increasing systemic lupus erythematosus activity were inconsistent, showing decreasing heart rate variability or no relationship. However, the low/high frequency ratio was, in some studies, reported to increase with increasing disease activity or to be inversely correlated with albumin levels.ConclusionsPatients with systemic lupus erythematosus have abnormal heart rate variability, which reflects cardiac autonomic dysfunction and may be related to inflammatory cytokines but not necessarily to disease activity. Thus measurement of heart rate variability could be a useful clinical tool for monitoring autonomic dysfunction in systemic lupus erythematosus, and may potentially provide prognostic information.

Angiotensin increases blood pressure without decreasing heart rate because it resets the baroreflex control of heart rate to a higher pressure. The resetting is mediated by central AT1 receptors and withdrawal of cardiac vagal tone. It is physiologically important because it minimizes baroreflex buffering and enhances the peptide's pressor activity.

The objective of minute ventilation (MV)-controlled pacemaker algorithms is to simulate the physiologic relationship of the sensed signal and the sinus node response during exercise. In our study we determined the relationship between heart rate and MV in healthy middle-aged subjects by measuring breath-by-breath gas exchange throughout peak exercise. Regarding several clinical limitations of peak exercise testing, we additionally evaluated whether a 35 W low-intensity treadmill exercise (LITE) protocol can be used as a substitute for peak exercise testing to determine the physiologic heart rate to MV slope. The results demonstrated that the heart rate to MV relationship is not linear throughout peak exercise but is curvilinear with a smooth logarithmic-type profile. To simulate this relationship, MV-based rate adaptive pacemakers should generate a decreasing heart rate to MV slope during higher levels of work. The heart rate to MV slope determined during the early, dynamic phase of low-intensity exercise represents the same slope derived from peak exercise below the anaerobic threshold. The low-intensity treadmill exercise protocol, with minimal patient effort, can thus be used as a substitute for peak exercise to optimize rate adaptive slope programming of MV-controlled pacemakers.

In this study the stability over the first 13 months of life of measures of infant cardiac activity (heart period and heart-period variability), their relations with each other, and their relations with a continuous-variable index of infant-mother attachment were investigated. The indexes of cardiac activity changed in an orderly way with development (increasing heart-rate variability, decreasing heart rate). There were moderate to high intercorrelations among the cardiac measures, particularly those indexing heart-rate variability (i. e., vagal tone, heart-period variance, and heart-period range)

Subjects in Phase 1 of this experiment were (a) instructed to try to either increase or decrease their heart rate, (b) with or without the use of biofeedback, and (c) with or without the promise of money for successful performance, whereas no-treatment subjects were given no instructions, no biofeedback, and no promise of reward. Results indicated that (a) when simply instructed to do so, subjects could increase but not decrease their heart rates relative to no treatment controls, (b) the promise of money for good performance aided subjects in increasing but not decreasing heart rate, and (c) biofeedback did not aid subjects in either increasing or decreasing heart rate. Various cognitive strategies employed by subjects in controlling their heart rates are discussed. In Phase 2, subjects in a stress condition were told that they would receive a series of painful electric shocks, whereas subjects in a no stress condition were not told about shocks. All subjects were instructed to try to decrease their heart rates during the “shock” period. Heart rate and self report data revealed that (a) the manipulation was successful in increasing stress, and (b) previous training in decreasing heart rate, with or without biofeedback, did not aid subjects in decreasing their heart rates in the face of the stress.

Dispositional differences in imagery vividness may account partially for the large individual differences in learning heart rate control. Based upon scores on the Betts QMI Vividness of Imagery Scale, 10 subjects were defined as a high imagery group and 10 subjects were defined as a low imagery group. All subjects were instructed to try to alter their heart rate as indicated by appropriately labeled lights. Six increasing, six decreasing and six rest, 45-sec trials were presented. During the trials, visual heart rate feedback was provided by a digital voltmeter. The dependent measure was computed by subtracting the mean of the last 5 beats of a 15-sec intertrial interval from the mean rate per trial. Results indicated that subjects were able to significantly raise and lower heart rate relative to rest trials. Furthermore, high imagery subjects demonstrated significantly larger changes than low imagery subjects on increase trials but not on decrease trials. Subjects in both groups typically reported using more specific images for increasing heart rate than for decreasing heart rate. These data suggest that dispositional differences in imagery vividness may have contributed to the differential performance of the two groups during the increase task.

Four patients who had suffered a myocardial infarction were given biofeedback training in order to assess (1) the possibility of increasing heart rate variability with the help of a feedback; (2) the possible cardiac consequences, from the clinical viewpoint, of biofeedback treatment. A biofeedback procedure alternately increasing and decreasing heart rate under instruction and feedback-plus-instruction conditions, was used. Evaluation of clinical parameters was effected by Holter dynamic ECG and by means of a graded submaximal effort test on the cycloergometer. The results show: (1) poor capacity to increase heart rate variability, but a tendency towards small unidirectional modifications; (2) no significant clinical modification except in isolated parameters. Further study is necessary to assess the usefulness of biofeedback training in the rehabilitation treatment of post-infarction patients. The datum, confirmed elsewhere, concerning apparent cardiovascular ‘rigidity’ in such patients, is interesting but requires clarification.

The effects of heart rate feedback delay upon bidirectional heart rate control were determined by comparing four groups of 10 subjects who received either: a) immediate feedback, or b) feedback that was delayed by 1.4 sec, 5 sec, or 14 sec. All subjects received 3 sessions of training which included 3 within-session phases, i.e. 2 (pre and post-feedback) Instructional Control phases during which subjects were instructed to speed or slow heart rate without the aid of feedback, and a Feedback phase during which bidirectional heart rate control was assisted by analogue heart rate feedback. Heart rate, chin EMG, and respiration rate were recorded during all phases. The results indicated that the magnitude of heart rate increases and decreases was systematically influenced by differing amounts of feedback delay. For increasing and decreasing heart rate, the group receiving immediate feedback showed superior heart rate control in comparison to groups which received feedback that was delayed by 14 sec. The strongest effects of feedback delay were evident during Feedback and the final Instructional Control phase. Only the group receiving immediate feedback improved HR control during Feedback and post-feedback Instructional Control phases. These findings were discussed in terms of a motor skills learning model for learned HR control. It was concluded that while many of the same parameters influence HR and motoric behavior, the two responses should not be regarded as equivalent.

Ten healthy men aged 18 to 23 years performed supine bicycle ergometer exercise during continuous echocardiographic recording. Beat to beat analysis of ventricular dimensions revealed that during constant work load exercise end-diastolic dimension did not change and end-systolic dimension decreased insignificantly by 4 percent. The stroke dimension and fractional shortening of the ventricular dimension rose 7 and 5 percent, respectively. During recovery, end-diastolic dimension and stroke dimension increased above the resting value, beginning 26 seconds (range 16 to 45) after cessation of exercise, whereas heart rate fell promptly to resting levels by 37 seconds. The peak increase in end-diastolic dimension and stroke dimension averaged 11 and 35 percent, respectively. Endsystolic dimension coincident with peak end-diastolic dimension decreased 11 percent in 6 of 10 subjects, and was unchanged in four. Fractional shortening of the ventricular dimension increased 8 percent (P These dimensional changes indicate a significant increase in end-diastolic dimension and stroke dimension in all 10 subjects during the recovery phase of supine exercise with a parallel rise in the percent shortening of the ventricular dimensions. During exercise a clear Frank-Starling effect is masked, whereas during recovery the continuing high level of venous return is dissociated from the decreasing heart rate, resulting in a transient increase in end-diastolic volume and a measurable Frank-Starling effect.

The effect of respiratory constraint on heart rate control was assessed in a biofeedback situation with feedback consisting of changes in both illumination level and intensity of a prerecorded baby's cry. Subjects were reinforced for alternately increasing and decreasing heart rate on each of seven days during which respiration was unconstrained (Phase 1). This phase was followed by eight days when respiration was constrained during training sessions with a control respirator (Phase 2). Seven additional days of training followed in the unconstrained situation (Phase 3). Results indicate that the control of heart rate in biofeedback situations is very closely related to respiratory and other somatic activity. The implication of these findings for the field of visceral control is discussed.

Subjects in this experiment viewed a stressful film and then received one of five treatments: (a) practice at increasing heart rate without feedback, (b) practice at decreasing heart rate without feedback, (c) practice at increasing heart rate with feedback, (d) practice at decreasing heart rate with feedback, or (e) a control condition. Subjects then returned on the following day, practiced controlling heart rate again (or sat quietly, for subjects in the control condition), and then viewed the stressful film again. Heart-rate results indicated that subjects in both feedback groups manifested tonic decreases in heart rate from the first viewing of the film to the second, whereas subjects in both of the no-feedback groups manifested no changes in heart rate between viewings, and subjects in the control condition manifested increases in heart rate between viewings. However, all five groups of subjects displayed phasic increases in heart rate during specific stressors in the film during both viewings. The tonic changes in heart rate noted between viewings of the film for the feedback groups were not accompanied by parallel changes in electrodermal activity or respiration rate. Self-report ratings of subjects' beliefs about ability to control heart rate were significantly correlated with the tonic changes in heart rate that were noted between viewings of the stressful film.

Fifty-six adult males who were hospitalized with anxiety related problems were randomly assigned to the conditions formed by a 2 (instructions to increase heart rate, instructions to decrease heart rate) × 3 (true biofeedback, placebo biofeedback, no biofeedback) factorial plus 1 (no-treatment control) design. Subjects were seen for 4 heart rate training/recording sessions and 1 subsequent transfer-test session. Results indicated that: a) neither instructions alone nor the combinations of instructions and true or placebo biofeedback were more effective than simply sitting quietly (adaptation) for decreasing heart rate, b) instructions plus true biofeedback was more effective than instructions alone or instructions plus placebo biofeedback for increasing heart rate, c) multiple sessions of training did not enhance the level of control achieved early in the first session, d) the control achieved with biofeedback did not transfer to a subsequent no-biofeedback situation, and e) biofeedback training did not influence subjects' subjective anxiety levels.