|Year : 2018 | Volume
| Issue : 3 | Page : 206-210
Acute hemodynamic response to pranayama in postcoronary artery bypass graft patients
Ekta Mohan1, Bishav Mohan2, Banveet Kaur Khetarpal3, M Rupinder Kaur4, Sunil Katyal4, Amol Nanak Singh3, Vivek Gupta5, Dinesh Garg5, Rajesh Arya5, Rohit Tandon2, Shibba Takkar Chhabra2, Naved Aslam2, Gurpreet Singh Wander2
1 Department of Anaesthesia, IVY Hospital, Bathinda, Punjab, India
2 Department of Cardiology, Dayanand Medical College and Hospital Unit Hero DMC Heart Institute, Ludhiana, Punjab, India
3 Department of Medicine, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
4 Department of Anaesthesia, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
5 Department of Cardiac Anaesthesia, Dayanand Medical College and Hospital Unit Hero DMC Heart Institute, Ludhiana, Punjab, India
|Date of Web Publication||11-Jan-2019|
Dayanand Medical College and Hospital Unit Hero DMC Heart Institute, Ludhiana - 141 001, Punjab
Source of Support: None, Conflict of Interest: None
Background: Pranayama is a science of breathing which involves prolongation and control of breath. It is known through various studies that yogic practices improve respiratory and cardiovascular function, reduce stress, anxiety and enhance overall well-being and quality of life. However, hemodynamic effects of short term yoga are not well known. Objective: To study the acute hemodynamic effects of pranayama in stable post coronary artery bypass grafting (CABG) patients. Study Design: Case control study. Methods: 60 post CABG patients were divided into - a) study group and b) control group (30 patients each). Cardiorespiratory parameters were noted in control group without pranayama and in study group, 5, 10, 15, 20 and 30 minutes after pranayama. Results were analyzed statistically. Results: There was a reduction in systolic blood pressure (126.10 ± 14.54 to 118.67 ± 13.74; p<0.05), diastolic blood pressure (63.1 ± 10.08 to 58.5 ± 8.1; p<0.05), respiratory rate (27.4 ± 5.1 to 22.7 ± 3.5; p<0.05) and systemic vascular resistance (1164.2 ± 189.8 to 1056.4 ± 153.2; p<0.05) after short term pranayama in the intervention group. The reduction was statistically significant when compared to control group. The heart rate, peripheral capillary oxygen saturation, cardiac output, cardiac index and pulmonary vascular resistance also changed but the change was not statistically significant in comparison to control group. Conclusion: Pranayama leads to decrease in systolic blood pressure, diastolic blood pressure, respiratory rate and systemic vascular resistance.
Keywords: CABG, CAD, hemodynamics, pranayama, yoga
|How to cite this article:|
Mohan E, Mohan B, Khetarpal BK, Kaur M R, Katyal S, Singh AN, Gupta V, Garg D, Arya R, Tandon R, Chhabra ST, Aslam N, Wander GS. Acute hemodynamic response to pranayama in postcoronary artery bypass graft patients. J Pract Cardiovasc Sci 2018;4:206-10
|How to cite this URL:|
Mohan E, Mohan B, Khetarpal BK, Kaur M R, Katyal S, Singh AN, Gupta V, Garg D, Arya R, Tandon R, Chhabra ST, Aslam N, Wander GS. Acute hemodynamic response to pranayama in postcoronary artery bypass graft patients. J Pract Cardiovasc Sci [serial online] 2018 [cited 2019 Jan 16];4:206-10. Available from: http://www.j-pcs.org/text.asp?2018/4/3/206/249929
| Introduction|| |
Pranayama and yoga are ways of lifestyle modifications. Regular practice of yoga significantly reduces arrhythmia burden, improves anxiety, depression, resting heart rate (HR), and blood pressure (BP), and improves quality of life in atrial fibrillation patients., It also has favorable effects on angina, body weight, lipid levels, and exercise capacity and leads to reduced need for revascularization procedures. Several researches reported that yogic intervention decreases coronary artery stenosis and sympathetic activity reducing stress and improving exercise capacity.,
Breathing exercises are shown to reduce respiratory muscle tone leading to widening of respiratory bronchioles and perfusion of large number of alveoli more efficiently. There is improvement in ventilatory functions of the lung, which leads to improved exercise performance in congestive heart failure patients. Buffalo health study revealed forced expiratory volume in 1 s as an independent predictor of overall long-term survival rate. Slow breathing stimulation through greater chest expansion successfully lowers BP and HR of hypertensive patients in postoperative period after coronary artery bypass grafting (CABG). However, the acute hemodynamic effects of pranayama have not assessed earlier. In this study, we intend to study acute hemodynamic effects of pranayama in post-CABG patients.
| Materials and Methods|| |
The study was conducted on 60 stable post-CABG patients aged between 50 and 70 years at a tertiary care hospital. Prior permission of the Institutional Ethics Committee and written informed consent from the patient was taken.
The study included 60 post-CABG patients who were conscious, oriented, breathing spontaneously with stable vitals, and left ventricular ejection fraction of 45%–60%. Patients were free of pain. All patients were taught breathing exercises before surgery. All patients had undergone off-pump CABG.
Exclusion criteria included patients who have refusal or unstable angina/acute myocardial infarction, patients on diuretics or inotropic support, and patients who were unable to perform or experienced significant pain in performing the exercises.
The flowchart of enrollment is shown in [Figure 1]. About 60 patients were randomly divided as follows:
- Study group (<i>n = 30; 21 males and 9 females) performed pranayama
- Control group (n = 30; 24 males and 6 females) did not perform pranayama.
All patients were instructed about the technique of pranayama 1–3 days before surgery by a qualified yoga instructor in three sittings. The patients were asked to perform pranayama (alternate nasal breathing) exercises on the 3rd–6th post-operative day, when they were extubated and hemodynamically stable, with radial arterial line and Swan–Ganz catheter still in-situ. The procedure was done in recovery area in a separate, quiet and dim lit room, maintaining a calm and peaceful environment.
Participants were asked to relax for 30 min in supine position before recording baseline vitals. HR, systolic BP (SBP), diastolic BP (DBP), respiratory rate (RR), and peripheral capillary oxygen saturation (SpO2) were recorded through the radial arterial line on a cardiac monitor (Siemens). Cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), and pulmonary vascular resistance (PVR) were recorded for both groups through Swan–Ganz catheter on a separate cardiac monitor (Edwards).
The study group was asked to perform alternate nostril breathing as per standard procedure. Accordingly, they were made to sit comfortably in a cross-legged position, keeping their spine erect, eyes closed, and breathe from alternate nostrils keeping one nostril closed. This exercise was done 10 times. The control group did not perform the breathing exercises but maintained similar posture.
Recordings of HR, SBP, DBP, RR, SpO2, CO, CI, SVR, and PVR were done after 5, 10, 15, 20, and 30 min of pranayama in study group and without pranayama in control group.
Results obtained were tabulated and analyzed using Student's unpaired t-test. P < 0.05 was considered statistically significant.
| Results|| |
[Table 1] compares the characteristics (age, sex, and visual analog scale [VAS] score) of the two groups.
|Table 1: Distribution of patients according to age, sex, and visual analog scale|
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The age distribution (P = 0.956) and sex distribution (P = 0.371) of patients among both groups were comparable. The pain status was assessed using VAS. The VAS score was higher in the control group (P = 0.019).
[Figure 2], [Figure 3], [Figure 4] depict all cardiorespiratory parameters measured at baseline (preyoga) and 30 min after performing pranayama (postyoga) in study group. The SBP significantly decreased from 126.1 ± 14.5 to 118.6 ± 13.7 (P < 0.05), DBP from 63.1 ± 10.08 to 58.5 ± 8.1 (P < 0.05), RR from 27.4 ± 5.1 to 21.3 ± 2.7 (P < 0.05), and SVR from 1164.2 ± 189.8 to 993.7 ± 133.7 (P < 0.05) acutely while performing pranayama.
|Figure 2: Effects of yoga in various parameters (heart rate, systolic blood pressure, diastolic blood pressure, relative risk, and SO2).|
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|Figure 4: Effects of yoga in systemic vascular resistance index and peripheral vascular resistance index.|
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The HR decreased from 102 ± 10.3 to 97.07 ± 10.4, SpO2 increased from 98.9 ± 1.4 to 99.2 ± 0.8, CO increased from 5.47 ± 0.6 to 5.7 ± 0.53, CI increased from 3.1 ± 0.4 to 3.3 ± 0.4, and PVR decreased from 121.03 ± 44.2 to 118.07 ± 46.2. However, these changes were not statistically significant.
[Table 2] depicts a comparison between the study and control group for cardiorespiratory parameters (SBP, DBP, RR, and SVR) at different time intervals of 5–30 min. While the baseline values were similar in the two groups, the SBP (at 15 min) and DBP, RR and SVR (at 10 min) decreased significantly in the pranayama group as compared to control and remained lower till the end of the intervention.
|Table 2: Comparison between study and control groups for heart rate, systolic blood pressure, diastolic blood pressure, respiratory rate, systemic vascular resistance index, peripheral vascular resistance index, cardiac output, cardiac index, and peripheral capillary oxygen saturation|
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| Discussion|| |
Pranayama led to acute decrease in SBP, DBP, RR, and SVR in patients performing yoga both in comparison to baseline values and as compared to the control group.
This is in accordance with the study by Dhungel et al. which showed decrease in SBP from 116.78 mmHg to 115.28 mmHg in healthy young volunteers. Another study by Joseph et al. in hypertensive patients showed that slow breathing decreases SBP from 149.70 mmHg to 141.10 mmHg. Our study also demonstrated a statistically significant decrease in DBP in the intervention group.
This change in SBP and DBP can be explained by the fact that deep slow breathing leads to increased intrathoracic volume and decreased intrathoracic pressure with increased venous return to the right side of the heart. This increases left ventricular output, which is sensed by baroreceptors present in the carotid sinus and aortic arch that transmit signals through glossopharyngeal and afferent vagal nerve to cardioregulatory and vasomotor center in the medulla oblongata in the brain stem. Increased activation of cardioregulatory center sends inhibitory signals (parasympathetic) through efferent vagal fibers to the heart which decreases HR. The cardioregulatory center also sends signals through sympathetic pathway and decreases sympathetic activity which decreases stroke volume and SBP. Decreased sympathetic flow to smooth muscles causes vasodilation and pooling of blood in periphery leading to decrease in peripheral resistance and DBP.
According to Joseph et al., decrease in BP during slow breathing (<10 breaths/min) is associated with improved baroreceptor reflex sensitivity, which suggests a change in autonomic balance resulting from an absolute or relative reduction in sympathetic activity or increase in parasympathetic tone.
In our study, statistically significant decrease has been found in RR with pranayama which is consistent with another study by Joshi et al. on healthy medical students for 6 weeks. Jain et al. also found a significant decrease in RR both after acute exposure and after 8 weeks of the right nasal and left nasal breathing. This decrease in RR could be because of certain amount of hypocapnea and also the persistent voluntary effort of breathing, which may produce an inhibition of the involuntary mechanism of breathing by a phenomenon akin to overdrive suppression.
In our study, CO and CI have increased significantly in study group at 30 min, while it remained almost constant in control group. However, when compared with control group, there was no statistically significant change between the two groups. This increase in CO, and hence, CI can be explained by the same mechanism as that for HR and BP change. The decreased peripheral resistance leads to increase in stroke volume and hence CO and CI. No study till date has been done to see acute or chronic effects of pranayama on CO or CI.
In our study, SVR significantly decreased at 10, 15, 20, and 30 min after pranayama. However, no changes have been found in PVR. No study till date has been done to see acute or chronic effects of pranayama on SVR or PVR. This change in SVR can be explained by the fact that deep and slow breathing during pranayama leads to increased intrathoracic volume and decrease in intrathoracic pressure increasing venous return to the right side of the heart which, in turn, increases left ventricular filling and left ventricular output. This observation could be because of lung inflation which has been known to decrease SVR. This response is initiated by pulmonary stretch receptors which bring about the withdrawal of sympathetic tone in skeletal muscle blood vessels leading to widespread vasodilation, thus bringing up decrease in peripheral resistance.
Yogic techniques decrease hypothalamic discharges leading to decreased sympathetic tone and SVR. Decreased release of catecholamine causes decreased sympathetic activity which causes peripheral vasodilation and decrease in peripheral resistance.
In our study, decrease in HR was seen in study group although not statistically significant difference in HR between two groups. This decrease in HR in study group may be due to the fact that pranayama involves concentrating on the act of breathing, which removes attention from worldly worries and “de-stresses.” This decreased stress reduces sympathetic activity and stress hormones (such as adrenaline) and enhances parasympathetic activity which reduces HR.
This is in accordance with a study conducted by Jain et al., which suggested that pranayama evokes generalized parasympathetic dominance. Another study by Dhungel et al. also showed that a significant decrease in mean pulse rate from 77.28 to 74.31/min was seen after 4 weeks. Similarly, a study by Gopal et al. to see the effect of yogasanas and pranayama on BP, HR, and some respiratory functions showed decrease in HR though not to a significant degree in trained persons before and after exercise which is probably due to increased parasympathetic tone found in athletes.
In our study, there is no statistically significant difference in PVR and SpO2 between two groups. This may be due to the fact that Sp02 was already greater than 92% in both study and control groups (before performing pranayama). This study is afirst of its kind to demonstrate the effects of relaxing techniques on SVR and other parameters in postoperative, stable CABG patients.
| Conclusion|| |
Pranayama acutely decreases SBP, DBP, RR, and SVR significantly in post-CABG patients which may be due to decrease in stress and sympathetic activity and increase in parasympathetic activity. Thus, pranayama may be a simple and cost-effective cardiorehabilatory adjunct to medical management in these patients and other patients of cardiovascular disease.
Even though utmost care was taken to avoid any errors in measurement, many factors can potentially influence the accuracy of measurement, for example, body position, white coat effect, medications, anxiety, measurement devices, and level of training of the observer.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2]