Effect of yoga therapy on cardiac function, response to exercise, oxidative stress and quality of life in heart failure patients: a randomized controlled trial.

Heart failure is the end stage of all diseases of heart and is a major cause of morbidity and mortality. The overall prevalence of the heart failure is 3-20 per 1000 population, although this exceeds 100 per 1000 in those aged 65 years and over. The overall incidence of heart failure is likely to increase in future, because of both increase in ageing population and therapeutic advances in the management of acute myocardial infarction leading to improved survival in patients with impaired cardiac function 15. Heart failure is one of the most prevalent chronic illnesses of the modern times with a profound clinical economic impact on society. The symptoms of the disease significantly reduce the quality of life among those live with HF1. HF ranks among the top chronic illnesses with a profound clinical and socioeconomic impact. The manifestation of this may lead to a significant reduction in quality of life. In patients with both systolic and diastolic HF, these symptoms often limit functional capacity3. The epidemic of heart failure is a leading cause of morbidity and mortality worldwide. The hallmark of this pathology is maladaptive ventricular remodelling that precipitates contractile dysfunction and ultimately leads to the overt syndrome of congestive heart failure. The central feature in this malignant cascade is typically the injury to cardiac myocytes, followed by replacement fibrosis, negative ventricular remodelling that ultimately leads to organ failure further accelerated by hemodynamic overload, inflammatory, oxidative stress and/or impaired vascularisation9. Autonomic system imbalance is associated with mortality in patients with cardiocascular diseases12. Autonomic system imbalance and weakened central haemodynamics forms the pathophysiological basis of the impaired cardiovascular function and decreased physical capacity of HF patients14. HF is a multisystem syndrome with the autonomic, neurohumoral abnormalities of increasing sympathetic and decreasing parasympathetic activity. Evidence of ANS dysfunction includes decreased HRV2. Heart failure is associated with severe impairment of exercise capacity, functional ability and health related quality of life 10. Original observations suggest that endothelial dysfunction may be evident in CHF patient, possibly due to enhanced ROS activity. Increased MDA and decreased concentrations of glutathione, Vitamin C & E  were correlated with NYHA functional class14. Progressive increase in free radical injury and encorchment on antioxidant reserves with the evolution of HF, they also suggest that oxidative stress may be an important determinant of prognosis. There was significant relation between the patients MDA levels and functional class 4. Recent experimental and clinical studies have suggested that generation of ROS to increase in chronic HF. ROS can cause contractile failure and structural damage to the myocardium. The importance of oxidative stress is increasingly emerging with respect to pathophysiological mechanism of LV remodelling and failure responsible for HF progression. Oxidative stress could be the mechanistic basis also for muscle fatigue and reduced exercise tolerance in HF patients. ROS play an important role in the muscle atrophy commonly seen in HF patients through the induction of apoptosis. Oxidative stress is now proved to play an important role in the development and progression of myocardial remodelling and failure 5. Multiple lines of evidence support the “cytokine hypothesis†which suggests that inflammation plays an important role in the development and progression of heart failure. Circulating markers of inflammation, such as C reactive protein may be useful in the diagnosis, gauging, prognosis and evaluating the response to therapy in patients with heart failure 6. HF is associated with increased oxidative stress, and many of our therapies proven to be of clinical benefit may have mechanisms of action related to reducing this stress in vivo. Increased oxidative stress is recognized to be important in the pathogenesis of cardiovascular disease including HF 7.

The management of patients with chronic congestive heart failure has changed considerably during the last decade until recently, restriction of physical activity was recommended for patients with chronic heart failure patients. However, the knowledge that training influences largely the peripheral rather than the heart itself has led to a dramatic change in the approach toward training in patients with chronic HF 11. India has a rich tradition of yogic practices. Now-a-days yoga, the ancient practice of postures, breathing and meditation is gaining a lot of attention from health care professionals with increasing scientific research in yoga, its therapeutic aspects are also being explored 16. Yoga is known for its beneficial effects on physiologic and psychological functions. During the last 3 decades, extensive physiologic research   has been done on yogic practices. It has been reported that yoga can increase muscular efficiency, endurance time and aerobic capacity and can reduce perceived exertion after exercise. Yoga is widely used as a stress reliever. Additionally yoga has a profound effect on ANS and may reduce stress level in individuals via this effect. Regarding oxidative stress reports have suggested that yoga can decrease oxidative stress reduce the malandialdehyde level and increase superoxide dismutase activity and catalase activity 8. Slowing respiratory rates reduces dyspnoea and improves both pulmonary gas exchange and exercise performance in patients with CHF 17. In addition to allowing for a predominance of the parasympathetic state, yoga may also promote effective extraction of oxygen by peripheral tissues. When muscle is stretched, the O2 composition increases 1. Yoga may upregulate the antioxidant capacity of cells to combat oxidative stress. Regular yoga practice can maintain or improve antioxidant level of the body 8. Yoga may improve functional capacity and quality of life by lowering sympathetic response to physical activity, leading to a reduction in cytokines and oxidative stress 1. Despite yoga’s wide spread appeal, there is no data on whether the addition of yoga therapy improves symptoms of health related QOL in patients with compensated HF 3.

Relevant References:

1. Paula R.Pullen,Walter R.Thompson et.al., “Benefits of Yoga for African American Heart Failure Patientsâ€. Medicine & science in sports & exercise  2010 ; 0195-9131/10/4204-0651/0.

2.    Jill Howie-Equivel , Jiyeon lee et.al., “Yoga in Heart failure : A Pilot study†, J Cardiac failure 2010 ; 16 : 742 – 749.

3. Pullen PR, Nagamia SH, Mehta PK, et al. “Effects of yoga on inflammation and exercise capacity in patients with chronic heart failureâ€. J Cardiac Fail 2008;14:407e13.
4. M ketih, A Germanmayegan et.al., “Increased oxidative stress in patients with congestive heart failure†J Am coll Cardiology 1998; 31; 1352-1356.
5. Hiroyuki Tsutsu., “Mitochondrial oxidative stress and heartfailure novel pathological insight and treatment strategies†Currnt Cardiology Reviews, 2005,1 37-44.
6. John W Petersen, Michael Felker et.al., “ Inflammatory Biomarkers in Heart failure†CHF 2006 ; 12 : 324-328
7. Lenong L. Ng, “Targetting oxidative stress in heart failure†Heart Metab. 2009; 42:21-24.
8. Snchari sinha, Som nath singh et.al., “Improvement of glutathione and total antioxidant status with yoga†The Journal Of Alternative and Complimentary Medicine†2007, 13;10: 1085-1090
9. Jozef bartunek “Biomarkers: old-new, cardiac-noncardiac, all paving the way for better stratification in heart failure†Biomarkers Med 2009;3(5):435-437
10. Miles D. Withmam, Ishabel S. Argo et.al., “Predictors of exercise capacity and everyday activity in older heart failure patients†The European Journal ofHeart Failure 8 2006; 203-207
11. Paul Dubach, Sebastian sixt et.al., “ Exercise training in chronic heart failure:Why,When,How†SWISS MED WKLY 2001;131 ; 510-514
12. Andrea Radzewitz,Eckart Miche et.al., “Exercise and muscle strength training and their effect on quality of life in patients with chronic heart failure†The Europen Journal of Heart failure 2002; 2 : 627-634
13. George Papathanasiou, Nikolaos Tsamis et.ai., “Beneficial Effects of Physical Training and Methodology of Exercise Prescription in Patients with Heart Failure†Hellinic J Cardiol 2008;49:267-277.
14. Carlene A. AHMILTON, William H. MILLER et.al., “Strategies to reduce oxidative stress in cardiovascular disease†Clinical Science 2004; 106: 219-234
15. R C Davis, F D R Hobbs et.al., “ABC of heart failure History and epidemiology†BMJ 2000; 320: 39-42
16. Kanwaljeet singh, Baljinder singh bal et.al., “The effect of suryanamskar yogasana on muscular endurance and flexidility among intercollege yoginis† Journal of Physical Education and Sport†2010;2:61-67
17. Luciano Bernardi, Giammario spadancini, “Effect of breathing rate on oxygen saturation and exercise performance in chronic heart failure†Lancet 1998; 351: 1308-11.