FIELD OF THE INVENTION
[001] The present invention relates to the field of medical science, and more particularly, the present invention relates to the acute effect of slow abdominal breathing on heart rate variability in pre-hypertensive.

BACKGROUND FOR THE INVENTION:
[002] The following discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to is published, known, or part of the common general knowledge in any jurisdiction as of the priority date of the application. The details provided herein the background if belongs to any publication is taken only as a reference for describing the problems, in general terminologies or principles or both of science and technology in the associated prior art.
[003] Pre-hypertension as defined by JNC seventh report is indeed a precursor of hypertension, with a conversion rate over the period of 4 years of about 30%, and is associated with an increased risk of major 2,3 cardiovascular diseases. Prevalence of pre-hypertension is continuously on a rise (47.4%) globally and is attributed to autonomic dysfunction being both a reason and consequence of hypertension. Both sympathetic over activity and vagal withdrawal contributes to pre hypertension in Indian population, with vagal withdrawal being a prominent cause in males. Currently several lifestyle modifications are being used globally as a non-pharmacological method to reduce high blood pressure that includes de-stress programs like meditation and other stress management technique. Stress management practices have been reported to reduce BP and multiple cardiovascular risk factors in 9,10 several studies. The beneficial effect of slow abdominal breathing /Diaphragmatic breathing has been seen in chronic obstructive diseases & hypertension by several investigators. Respiration being under both voluntary and involuntary control can be varied voluntarily as per the need and from person to person. Diaphragmatic breathing is one of the most useful stress reduction techniques and consists of a slower respiration rate (<8) with large tidal volume inhalation and abdominal contraction during exhalation. Since the respiratory sinus arrhythmia is increased and is in phase with the breathing pattern this approach evokes an alternative for control of autonomic nervous system.
[004] In light of the foregoing, there is a need for study of the acute effect of slow abdominal breathing on heart rate variability in pre-hypertensivethat overcomes problems prevalent in the prior art.

OBJECTS OF THE INVENTION:
[005] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
[006] The principal object of the present invention is to overcome the disadvantages of the prior art by providing the acute effect of slow abdominal breathing on heart rate variability in pre-hypertensive.
[007] An object of the present invention is to provide the acute effect of slow abdominal breathing on heart rate variability in pre-hypertensive thatexamines the effect of slow abdominal breathing on vagal tone in young adults and hence reduction in blood pressure.
[008] Another object of the present invention is to provide the acute effect of slow abdominal breathing on heart rate variability in pre-hypertensivewhich is one of the most useful stress reduction techniques and consists of a slower respiration rate (<8) with large tidal volume inhalation and abdominal contraction during exhalation.
[009] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

SUMMARY OF THE INVENTION:
[010] The present invention provides an acute effect of slow abdominal breathing on heart rate variability in pre-hypertensive.
[011] According to one aspect of our invention, the study observes the effect of slow abdominal breathing on blood pressure (BP) and relate these changes to Heart Rate Variability (HRV) in prehypertensive.
[012] In another aspect of the invention, the self- controlled prehypertensive volunteers are subjected to intervention of slow abdominal breathing @ of 6 breaths/min and record the ECG using standardized procedure for HRV analysis along with the systolic (SBP) and diastolic (DBP) blood pressure during their pre intervention period[@ of 20 breaths/min],the intervention period & post intervention period [@ of 20 breaths/min].
[013] In another aspect of the invention, recorded data in three stages are analyzed using paired “t” test and Pearson test for correlation with a “p” value of <0.05 as level of significance.
[014] In another aspect of the invention, the study observed a marked decrease in mean SBP & DBP (P =0.001) in addition to significant decrease in mean sympathetic activity (L.F.) &increase in parasympathetic activity (H.F) (P value <0.05) during slow abdominal breathing @ 6 breaths/min from the pre intervention period @ 20 breaths/min in pre hypertensives subjects.
[015] In another aspect of the invention, later on increasing the breathing rate to @ 20 breaths /min from 6 breaths/min showed a significant reversal of the values of HRV parameters, SBP and DBP in the period of post intervention.
[016] In another aspect of the invention, negative though non-significant relation is observed between blood pressure reduction and change in vagal tone (HF).
[017] In another aspect of the invention, slow abdominal breathing at 6 breath /min acutely decreases the SBP and DBP in prehypertensive which may be due to increase in the vagal tone [HF] with decreases in the excitability in sympathetic system [LF, LF/HF].

BRIEF DESCRIPTION OF DRAWINGS/ TABLES:
[018] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
[019] Table 1A shows a table for blood pressure during breathing in accordance with the present invention.
[020] Table 1 shows a table for demographic, anthropometric parameters and cardiovascular parameters of volunteers(n=22) in accordance with the present invention.
[021] Table 2 shows a table for blood pressure changes during breathing rate of 20breath/min and 6 breath /min(n=22) in accordance with the present invention.
[022] Table 2A shows a table for intervention period with breathing rate @6 breath/min in accordance with the present invention.
[023] Table 3 shows a table for 3 autonomic function assessment during the study protocolin the volunteers(n=22) in accordance with the present invention.
[024] Figure 1 shows a graph for mean systolic and diastolic blood pressure during intervention in different rates in accordance with the present invention.
[025] Figure 2 shows a graph for mean autonomic function at different breathing rates in accordance with the present invention.

DETAILED DESCRIPTION OF DRAWINGS/TABLES:
[026] While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and the detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claim.
[027] As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein are solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers, or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles, and the like are included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all these matters form part of the prior art base or are common general knowledge in the field relevant to the present invention.
[028] In this disclosure, whenever a composition or an element or a group of elements is preceded with the transitional phrase “comprising”, it is understood that we also contemplate the same composition, element, or group of elements with transitional phrases “consisting of”, “consisting”, “selected from the group of consisting of, “including”, or “is” preceding the recitation of the composition, element or group of elements and vice versa.
[029] The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the claims. In addition, several materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention.
[030] The present invention provides an acute effect of slow abdominal breathing on heart rate variability in pre-hypertensive. Based on the sample size calculation for this experimental design witheffect size of 0.17 at alpha error of 0.05, power of 80% & pooled SD of14 0.13 a total of 22 volunteers of age group 20-40 years are includedafter a written informed consent. Pre-Hypertensive according to WHO/JNC VII classification with mean systolic BP between 120- 139mm Hg and/or a diastolic BP between 80- 89 mm Hg and not on antihypertensive medication. Hypertension (BP=140/90 mm Hg), secondary hypertension, Clinical cardiovascular disease, stroke, Diabetes (fasting plasma glucose =126 mg/dl), Chronic Renal Disease, Current use of anti-diabetic medications or insulin, Heavy alcohol consumption, Current use of a low sodium salt in diet. The study population is screened for blood pressure as per the standardized protocol of JNC 7 and those diagnosed as pre hypertensive are recruited for the study. After fulfilling the inclusion and exclusion criteria the volunteers are called at the Department in the morning and administered pre formed questionnaire for recording of demographic and anthropometric data. Volunteers are than subjected to recoding of resting heart rate, respiratory rate, and ECG. Each subject is informed about the interventional protocol and it`s methodology to allay their anxiety.
[031] 1. PRE-INTERVENTION- parameters observed are –
- Resting pulse rate
- Respiratory rate.
- Basal blood pressure
[032] - Vagal Tone- following a rest of 10minutes volunteer are asked to perform slow abdominal breathing at the rate of 20 breaths/minute for 10 minutes duration using a visual meterome. The data isanalysed using SPSS Software version 20. Data is presented as mean /SD for quantitative variables like blood pressure, % body fat and parameters of HRV. Differences across the groups i.e., pre intervention, intervention & post intervention is analyzed using analysis of variance with repeated measures and by paired “t” test. Probability is set at less than 0.05 as significant. 22 self- controlled prehypertensive volunteers are subjected to the slow abdominal breathing at the rate of 6 breaths/min and heart rate variability is recorded using standardized procedure during the intervention along with the blood pressure to assess the acute change in both systolic and diastolic blood pressure from their pre intervention period.
[033] Mean age of the volunteers in our study is 28.32±8.24 years with none of the volunteers included in my study being obese [BMI of 25.7±2.1 kg/m2]. During the study, the mean pulse rate and respiratory rate of the volunteers are estimated to be 88.27±7.1 breaths/min and 17.23±1.5 breaths/min respectively. The mean systolic and diastolic blood pressure is within limits of prehypertension. st During the 1 intervention with breathing at the rate of 20 breaths/min there is decrease in the SBP but the fall is insignificant. No change in the mean value of DBP is observed following the intervention. (P value >0.05). When the intervention is changed to 6 breaths/min, there is marked decrease in SBP [125.4 vs 118.7mmHg] and the fall is statistically significant (p=0.001). A significant decrease in DBP is also observed (P =0.001). When the volunteers are again shifted to breath at 20 breaths per minute no change in the pre and post SBP&DBPis observed.
[034] When the breathing rate of the volunteers are changed from 20 breaths/min to 6 breaths/min (between intervention 1 and 2) there is a marked significant decrease in sympathetic activity (L.F.) with a marked & significant rise in parasympathetic activity ( H.F) (P value <0.05) . A significant decrease in LF/HF ratio is observed. On reversal of the breathing rate from 6 breath/min to 20 breath/min the converse to the above is observed with a significant rise in sympathetic activity (L.F.) &a significant decrease in parasympathetic activity (H.F.) (Pvalue<0.05) with a significant increase in their ratio. On comparing between intervention 1 and 3, there is neither a significant change in sympathetic activity nor parasympathetic activity is observed (Pvalue>0.05). Analyzing for correlation of the change in blood pressure and change in sympathetic and vagal tone observed weak but positive & negative relationship correspondingly. The breathing rate shift from 20 breath/min to 6 breath/min definitely brought down the LF and raised the HF but it is not related to the change in blood pressure with LF & HF and the changes in blood pressure parasympathetic activity (H.F.). On again changing the breathing rate to 20 breaths/min there is marked and significant increase in sympathetic activity with decrease in parasympathetic activity. Reciprocal changes are change observed in ratio of L.F. and H.F. during the change in the intervention.
[035] High blood pressure is a known risk factor for cardiovascular diseases with several recent studies suggesting that prehypertensives are also at greater risk for developing both the above comorbidities. Prehypertension regarded as normal blood pressure is cross sectionally associated with subclinical atherosclerosis and target organ damage with it being an important risk factor for the above cause it is essential to find non-pharmacological methods to decrease the blood pressure in early stage. The present study observed the acute effect of slow controlled breathing @ of 6 breaths/ min on the SBP and DBP and its association with the change in heart rate variability. We observed a significant fall in both SBP and DBP during a controlled breathing @6 breath/min. Breathing at a higher rate of 20 breath /min did not observe the fall in both the pressures. Similar acute effect of the slow controlled breathing is observed by Wang et al in their study on post-menopausal women and the effect continued for a period of 6 months. Our results are also similar to study by Joseph et al which observed a fall in blood pressure immediately after the slow controlled breathing but in contrast to our study the intervention trial observed a stronger effect of slow breathing over fast breathing in reduction of blood pressure. Our results are also similar to study by Pinheiro CH et al which observed modulation in CVS including a fall in SBP, DBP & MAP after a slow breathing training in essential hypertension subjects. Several studies have observed a significant fall in blood pressure [S/D: 5.5/3.5mmHg] in mild hypertensives by using a device guided breathing for a period of 2 weeks. Cardiovascular parameters recorded during the slow breathing for 10min resulted in significant fall in SBP, DBP and Heartrate even in a single session but in hypertensive receiving antihypertensive and those un medicated by Kaushik et al. A study using controlled breathing if form ofsuch pranayama @ 6 breath/min also reduced the Heart rate andcaused significant fall in SBP, pulse pressure but a insignificant fall inDBP in hypertensive's which is related to increased vagal modulationand /or decreased sympathetic activity and improved baroreflexsensitivity.
[036] However, there isa dissimilarity of our work with the work done byAltena et al which observed that slow abdominal breathing relaxationonly had a relatively long-term effect on the SBP, but no remarkableeffect on SBPin the follow-up, and also has no significant effect on thediastolic pressure. Another study also observed a significant fall inSBP in prehypertensive women following slow breathing but had noeffect on DBP.
[037] The mechanism by which slow abdominal breathing reduces bloodpressure is observed using the HRV analyses that reflect cardiacautonomic nervous function which could be the potential mechanismunderlying the BP changes. Our study observed that theparasympathetic drive is enhanced with a corresponding fall insympathetic (LF) when volunteers are asked to breath from breath/min to slow controlled breathing @6 breath /min (Fig2). Thechange in sympathetic and parasympathetic drive due to change inbreathing pattern showed much similar results with the work reportedby Joseph et al and Bernardi et al as the possible mechanism ofreduction in blood pressure.
[038] Such change in the autonomic function tests using standing to lyingratio, hand grip and 30:15 ratio is also observed by study conductedby Mourya M on subjects with stage 1 hypertension following slowbreathing exercises.Results of our study is also strengthened by thestudy in which controlled breathing caused a decrease in lowfrequency variation and LF/HF variation in normotensives andhypertensive although the LF fall is less in hypertensive, but theLF/HF ratio decreased more in them suggestive of a higher rise in HFvariation of R-R interval.
[039] The mechanism behind reducing blood pressure by changing vagaltone through slow abdominal breathing in pre-hypertensives may be byimproving arterial baroreflex sensitivity,reducing sympatheticactivity and reducing chemoreflex sensitivity (deriving from theactivation of the Hering-Breuer reflex induced by the increased tidalvolume), which in turn enhances the baroreflex sensitivity. Consistent with other non-pharmacological intervention to lower the BP in hypertensive, slow abdominal breathing can effectively reduce BP in those suffering from prehypertension possibly by increasing the excitability of the vagus Nerve and reducing the excitability of sympathetic nerves. Slow abdominal breathing @6 breaths /min alters the autonomic activity of body by increasing parasympathetic activity(HF)and decreasing sympathetic (LF) simultaneously which is reflected as fall in SBP and DBP both in pre hypertensive.
[040] The disclosure has been described with reference to the accompanying embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein.
[041] The foregoing description of the specific embodiments so fully revealed the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.

We Claim:

1) A medical study of an acute effect of slow abdominal breathing on heart rate variability in pre-hypertensive, the medical study includes a total of 22 volunteers of age group 20-40 years;
Wherein based on the sample size calculation for this experimental design witheffect size of 0.17 at alpha error of 0.05, power of 80% & pooled SD of14 0.13.

2) The medical study as claimed in claim 1, wherein the study observes the effect of slow abdominal breathing on blood pressure (BP) and relate these changes to Heart Rate Variability (HRV) inprehypertensive.

3) The medical study as claimed in claim 1, wherein 22 self- controlled prehypertensive volunteers are subjected to intervention of slow abdominal breathing @ of 6 breaths/minand record the ECG using standardized procedure for HRV analysis along with the systolic (SBP) and diastolic (DBP)blood pressure during pre-intervention period[@ of 20 breaths/min],the intervention period & post intervention period [@ of 20 breaths/min].

4) The medical study as claimed in claim 1, wherein recorded data in threestages areanalyzed using paired “t” test and Pearson test for correlation with a “p” value of <0.05 as level of significance.

5) The medical study as claimed in claim 1, wherein the study observed amarked decrease in mean SBP & DBP (P =0.001) in addition to significant decrease in mean sympathetic activity (L.F.) & increase inparasympathetic activity(H.F) (P value <0.05) during slow abdominal breathing @ 6 breaths/min from the pre intervention period @ 20 breaths/min in pre hypertensives subjects.

6) The medical study as claimed in claim 1, wherein later on, increasing the breathing rate to @ 20 breaths /min from 6 breaths/min showed a significant reversal ofthe values of HRV parameters, SBP and DBP in the period of post intervention.

7) The medical study as claimed in claim 1, wherein negative though non-significant relation is observed betweenblood pressure reduction and change in vagal tone (HF).

8) The medical study as claimed in claim 1, wherein slow abdominal breathing at 6 breath /min acutely decreases the SBP and DBP inprehypertensive which may be due to increase in the vagal tone[HF] with decreases in the excitability in sympathetic system[LF,LF/HF].