Effects of Different Breathing Paces on Hemodynamic in Human Subjects - Lab Report Example

Effects of different breathing paces on hemodynamic in human s: comparison of supine and standing positions CHAPTER 4: DISCUSSION The main objective of the study was determining the different breathing paces on the hemodynamic in human subjects by comparison of supine and standing positions. There were a number of specific objectives. The first one was to investigate the breathing rate of hemodynamic in supine human subjects. The second one was to determine the breathing rate of hemodynamic in human subjects at standing postures. The third one was to compare the breathing rate between the standing and supine human subjects. The fourth one was to identify the factors that lead to the difference in the breathing rate between the supine and standing human subjects (Watanabe, Reece and Polus, 2007:5). The results recorded a substantial decrease in StV (7%, p< 0.001) during the 3 bpm intervention period. The result was similar kind of decrease in the CO by 6%. The pattern was characterized by RSA (respiratory sinus arrhythmia) being common. The RSA entailed an increase in the heart rate during exhalation and inhalation while during the holding part it experienced a decrease. During the 3 bpm, MAP was not affected by the reduction of CO and the increase in TPR. In contrary, during the 6 bpm pattern, both the DBP and SBP experienced a decrease (p< 0.001) that corresponded to MAP decrease of 3%. During the initial higher increases of inhalation (approximately the first 75 seconds of inhalation), StV experienced significant increases (p< 0.01). After the collapse of the 75 seconds, there was no change on the StV during the rest of the period of intervention. The study findings showed that in a relaxing position, the blood pressure and heart rate decreases and slow breathing reduce blood pressure. 4.1 Intervention and Post Intervention Period 4.1.1 Six Breaths per Minute in Standing Position Study by Kappagoda, Linden and Snow (1972: 193) agree that the frequency of breathing influence the measures of baroreflex. The study also holds that there is need for repeated study so that the results can be compared for reliability. Even though it does not identify, the study shows emphasis that there are additional factors that influence baroreflex measurement. Joseph et al (2005: 714) argues that the frequency of breathing influences time offset strongly. It also adds that the posture of the individual used as a sample has much impact on the sensitivity of the baroreflex. Even though the concepts, aims, and methodology differ, the study links to the article by Joseph et al (2005: 714) which holds that slow breathing reduces blood pressure. 4.1.2 Six Breaths per Minute in Lying Position (Red Circle Line) Faster breathing rates leads to a heart rate that is higher compared to the normal rate. The fall in MAP during intervention can be linked to the autonomic balance shift. The autonomic balance is affected by the increased activation of the pulmonary stretch receptors found in the lungs. The receptors react to the situation through the release of signals that inhibits thus decrease in sympathetic tone. According to Joseph et al (2005: 714), higher breathing rate leads to an increase in the sympathetic nerve activity. The study was characterized by a significant decrease in DBP and SBP among the control group subjects. The PNS blocker made there be no change experienced at this level by impacting the parasympathetic activity. According to Kappagoda, Linden and Snow (1972: 193) stretching the superior vena cava of the junction of the right atrium, produces a reflex heart rate increase. The study shows that the lying position in relation placement of the neck affected the results. 4.1.3 Three Breaths per Minute in Standing Position A study by Gislof et al. (2005: 1682) shows the slower breathing rate leads to a heart rate that is lower compared to the normal heart rate. The challenges that are experienced in conducting such a study are mainly linked to the difficulty experienced in trying to control the breathing rate. The difficulty, therefore, explains the abnormalities that were recorded during the study. The difficulty makes the study be characterized by different respiratory and cardiovascular signals. The study even though does not focus on the positions it shows that standing has got an increased sympathetic response (Gislof et al., 2005: 1682). 4.1.4 Three Breaths per Minute in Lying Position Study by Pramanik et al (2008: 293) even though does not directly address the issue in this study; it shows that there are several ventilations even in slow breathing. Three breaths are less significant in terms of respiratory function compared to six breaths. Six breathes are sufficient to move the blood gases in perceptibly shift. The breath rate determines the arterial oxygen and carbon (iv) oxide (mm Hg) in the subjects. It, therefore, means an incomplete breath is cleansing and energizing. The weakness of the article is that it does not define the complete and incomplete breath. Pramanik et al (2008: 293) agrees that slow breathing leads to fall in the heart rate due to fall in the diastolic and systolic blood pressure. The article, therefore, encourages exercises thus increase the breathing rate. The difference is that the article emphasis on the “slow bhastrika pranayamic”. 4.2 Comparison of the two Breathing Paces and Positions 4.2.1 Comparison between Lying and Standing Positions in 6 Breaths per Minute Similar study effect was recorded by Pramanik, Pudasaini and Prajapati (2010: 154) that showed that BRS recorded in standing positions was more predictable compared to the supine position. Kappagoda, Linden and Snow (1972: 193) did not put much focus on the BRS but took consideration of the blood pressure and heart rate. The units of measurement similar to the one of this study were in the form of bpm/mm Hg. The recordings showed that magnitude fell between the lying and standing positions. Kappagoda, Linden and Snow (1972: 194) showed that blood pressure and heart rate were constant in both the lying and standing positions. The results agree with the findings of Kappagoda, Linden and Snow (1972: 194). The study findings showed that in a relaxing position, the blood pressure and heart rate decreases. Jones et al. (2003: 69) showed that the HR in standing position is higher compared to a lying position. According to Watanabe, Reece & Polus (2007: 1), the body posture plays a role in variability of heart rate. Even though the study by Verheyden et al. (2010: 646) was concentrating on a different test, it affirms that comparison between lying and standing position sis viable. 4.2.2 Comparison between lying and standing position in 3 breaths per minute There is an occurrence of bradycardia as breath is held. It is common among the lying compared to the standing subjects. Study by Gislof, et al. (2005: 1682) show that it is normal even though the studies have different methodologies and results. The study links the bradycardia effect to the sympathetic and vagal stimulation since the breath is lower than 9 bpm. According to Radaelli et al (2003: 1361), RSA is common during the slower patterns of breathing. They support the study by showing that slow breathing rate that is characterized by relaxing body reduces heart rate. The study by Gislof, et al. (2005: 1682), agrees with the finding by showing that sympathetic response increased by standing. 4.2.3 Comparison between the two breathing paces on standing position The brief response time is due to the vagus nerve secretion of the acetylcholine in SA heart node (Radaelli et al 2003: 1362). The sympathetic nerve endings secretes norepinephrine binds β1 receptors, thus an increase in the intracellular cAMP. According to Radaelli et al (2003: 1361) the time taken during the process is longer compared to vagal effect. Therefore, the sympathetic control of HR can be experienced only during the low breathing frequencies. Vagus can bring both high and low heart rate frequency change. The normal breathing frequency is in the HF range therefore respiration modulates only the activity of cardiac vagal (Banasik & Emerson, 1996: 121). According to Banasik & Emerson (1996: 121) slow breathing reduces the respiratory rates and increases HRV in the standing position. The study shows that reduction of the respiratory frequency modulates the sympathetic activity. The standing position makes the process so obvious with the increase in sympathetic tone. During standing, vagal activity is decreased significantly contrary to the HRVdb. HRVdb can therefore not be used as a litmus test for cardiac vagal modulation extent. An increase in the basal sympathetic tone due to factors like cardiac failure and anxiety makes the HRVdb include sympathetic activity. The work of Bernardi et al (2002: 143) supports the findings by showing that slow breathing increases the baroreflex sensitivity. 4.2.4 Comparison between two breathing paces on lying position According to the study, lower breathes per minute reduce the DBP, MAP, HR and TPR (Bernardi et al, 2001: 2221). On the other hand, higher breathes per minute decreases CO and StV significantly (Banasik & Emerson, 1996: 121). Time plays a factor in the amount of decrease experienced by the higher breathes per minute on DBP, MAP and SBP. The result of this study agrees with the finding of the study by Bernardi et al (2002: 143). Even though it does not tackle the main objective directly it compares the slow and fast breathing rates. The study shows that slow breathing rate have increased baroreflex sensitivity. The study by Bernardi et al (2001: 2221) uses the breathing rate of 6 bpm also to determine the effects of slow breathing. The study by Martin Du- Pan, Benoit & Girardier, (2004: 543) show that lying in the supine position increases sleep apnoea severity. The view is also supported by Banasik & Emerson (1996: 121). References Banasik, J. & Emerson, R. J. (1996) ‘Effect of lateral position on arterial and venous blood gases in postoperative cardiac surgery patients’, American Journal of Critical Care ,Vol. 5, July, pp. 121- 126. Bernardi, L. et al (2001) ‘Slow breathing reduces chemoreflex response to hypoxia and hypercapnia, and increases baroreflex sensitivity’, Journal of Hypertension, Vol. 19, July, pp. 2221- 2229. Bernardi, L. et al. (2002) ‘Slow Breathing Increases Arterial Baroreflex Sensitivity in Patients with Chronic Heart Failure’, Circulation,Vol. 105, August, pp. 143- 145. ‘Orthostatic blood pressure control before and after spaceflight, determined by time-domain baroreflex method’, Journal of Applied Physiology, Vol. 98, No. 5, May, pp Gislof, J. et al. (2005). 1682- 1690. Jones, A.Y. M et al (2003) ‘Slow breathing reduces chemoreflex response to hypoxia and hypercapnia, and increases baroreflex sensitivity’, The Chinese Journal of Physiology, Vol. 46, No. 2, January, pp. 63- 69. Joseph, C. K et al (2005) ‘Slow Breathing Improves Arterial Baroreflex Sensitivity and Decreases Blood Pressure in Essential Hypertension’, Hypertension, Vol. 46, July, pp. 417-418. Kappagoda, C.T., Linden, R. J. & Snow, H. M. (1972) ‘A reflex increase in heart rate from distension of the junction between the superior vena cava and the right atrium’, Journal of Physiology, Vol. 220, July, pp. 117- 197. Martin Du- Pan, R. C, Benoit, R. & Girardier, L. (2004) ‘The role of body position and gravity in the symptoms and treatment of various medical diseases’, Swiss Medical Weekly, Vol. 134, August, pp. 543- 551. Narkiewicz, K. et al. (2005) ‘Sympathetic Neural Outflow and Chemoreflex Sensitivity are Related to Spontaneous Breathing Rate in Normal Men’, Journal of American Heart Association, Vol. 47, December, pp. 51- 55. Pramanik, T. et al. (2009) ‘Immediate Effect of Slow Pace Bhastrika Pranayama on Blood Pressure and Heart Rate’, The Journal of Alternative and Complimentary Medicine, Vol. 15, No. 3, August, pp. 293- 295. Pramanik, T., Pudasaini, B & Prajapat, R. (2010) ‘Immediate effect of a slow pace breathing exercise Bhramari pranayama’, Nepal Medical College Journal, Vol. 12, No. 3, August, pp. 154- 157. Radaelli, A. et al. (2004) ‘Effects of slow, controlled breathing on baroreceptor controlof heart rate and blood pressure in healthy men’, Journal of Hypertension, Vol. 22, March, pp.1361–1370. Verheyden, B. et al. (2010) ‘Operational point of neural cardiovascular regulation in humans up to 6 months in space’, Journal of Applied Physiology, Vol. 108, No. 3, March, pp. 646- 654. Watanabe, N., Reece, J. & Polus, B. (2007) ‘Effects of body position on autonomic regulation of cardiovascular function in young, healthy adults’, Chiropractic & Osteopathy, Vol. 15, No. 19, November, pp. 1-8. Watanabe, N., Reece, J. & Polus, B.I (2007) ‘Effects of body position on autonomic regulation of cardio vascular function in young, healthy adults’, Chiropr Osteopat, Vol. 15, No. 19, November, [Online], Available: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2222597/ [9 may 2015] Read More