1 overview of Cardiovascular disease (CVD)

Cardiovascular disease is as one of the important causes of death in the world, although coronary heart disease mortality rate declined in recent decades, but there are still about 1.8 million deaths a year in Europe [1], in the United States each year, 785000 new cases and 470000 cases of repeated occurrence of myocardial infarction [2], and in the UK, about 110000 men and 65 a year, Acute myocardial infarction occurred in 000 women, equivalent to one case every three minutes [3]. Patients with cardiovascular disease illness delay, the course of the disease is long, often repeated, intermittent attacks, especially when patients are tired symptoms are more serious, if not timely take measures to intervene, it may induce angina pectoris, myocardial infarction and other symptoms, seriously affect the physical and mental health of patients.

The prevalence of CVD in China has continued to increase since 2006, with approximately 290 million CVD patients including 13 million with stroke, 11 million with coronary heart disease (CHD), 5 million with pulmonary heart disease, 4.5 million with heart failure (HF) and 2.5 million with rheumatic heart disease. Two million people have congenital heart disease and 245 million have hypertension [4]. Two-fifths of deaths in China are attributed to CVD, higher than those caused by cancer or other diseases.

Apart from drug and surgical treatment, cardiac rehabilitation training is of great value to improve the prognosis of patients. Studies have shown that cardiac rehabilitation training is helpful to improve patients' cardiac function, regulate blood lipids, improve myocardial function, improve exercise capacity, prevent complications, reduce the rate of rehospitalization, and further improve patients' quality of life [3].

2. Rehabilitation strategies for cardiovascular disease

2.1 Rehabilitation of cardiovascular diseases

Cardiac rehabilitation is a multidisciplinary intervention tailored to individual patients with various CVD (such as ischaemic heart disease, heart failure, and myocardial infarction) or patients who have experienced cardiovascular interventions (such as coronary angioplasty or coronary artery bypass grafting) [5]. The American Cardiovascular and Pulmonary Rehabilitation Association and the American Heart Association (AHA) emphasize that cardiac rehabilitation aims to optimize physical, mental, occupational and social functioning while slowing or reversing the CVD process [6, 7]. Cardiac rehabilitation usually begins during hospitalization and is followed by outpatient rehabilitation after discharge, including exercise programs, nutritional counseling, behavioral counseling, immunization and smoking cessation programs, and medical services aimed at controlling blood pressure, lipid levels, and diabetes [5].

An athletic training program usually consists of 36 sessions, supervised by a professional, and typically lasts 12 weeks. These exercises are performed under continuous ecg supervision by a qualified nurse, physiotherapist, exercise physiologist or physician. Exercise training takes place 1 to 3 times per week (depending on the individual), with the goal of 30 minutes of aerobic exercise per day, 5 days per week [8].

2.2 Difficulties faced by traditional rehabilitation

Studies have confirmed that traditional rehabilitation training can effectively improve the physiological outcome, biochemical outcome, physiological function, quality of life and depression of patients with cardiovascular disease. But one of the challenges of traditional rehabilitation is that the level of active participation in cardiac rehabilitation is still very low. It is particularly low among the elderly, women and patients of lower socioeconomic status. According to the latest Euroaspire V data, only about 50% of patients in Spain participate in cardiopulmonary rehabilitation training. The Reureca registry reports that only 10 percent of patients who are adapted to cardiopulmonary rehabilitation have been trained for rehabilitation.

New technologies in the field of health therefore need to improve this aspect. New technologies in cardiac rehabilitation programs using virtual reality (VR) and video games have been shown to improve compliance, training satisfaction and participation rates, and contribute to improved athletic performance [9, 10].

The role of virtual reality technology in cardiovascular rehabilitation

3.1 Virtual reality technology

Virtual reality (VR) is a Virtual environment created by a computer system, which can produce real simulation scenes, so that users can be immersed in them and interact with objects in the environment [12-14]. Therefore, simulation, interaction and immersion are the three basic elements of VR system [15]. Nowadays, with the development of more functional and easy-to-operate games, virtual technology is no longer a simple way of leisure entertainment, but a means of learning and skill training, especially for patients with motor, cognitive and sensory (neurological and non-neurological) disorders [11].

3.2 Advantages and benefits of virtual reality technology in cardiac rehabilitation

Traditional cardiac rehabilitation requires repeating similar exercises, which can cause some patients to lose interest in training. Video games and VR systems provide patients with interesting game tasks for therapeutic purposes through physical interaction with games [11]. Exercise-based video games (Exergames) are designed to provide fun ways to exercise physical skills and to adjust the level of play according to the patient's ability and intensity level. It is well known that the level of pleasure of an activity can be one of the predictors of the effectiveness of an exercise program, so exercise-based interactive technologies are becoming an important and popular strategy for the implementation of physical exercise [11].

The most commonly used VR cardiac rehabilitation systems are Kinbox or Nintendo Wii's XBOX, which are low-cost and easily accessible [11]. Chaddha's study found that the metabolic rates of healthy adults using the Wii and Wii Sports software ranged from 1.3 to 5.6 METS [12], and such pairs could be equivalent to the energy expenditure of a slow (for 1.3METS value) or very fast (for 5.6) walk. In most current studies, VR is combined with traditional cardiopulmonary rehabilitation, which is regarded as the Complement of traditional cardiopulmonary rehabilitation. However, two studies also used VR as a treatment method for cardiac rehabilitation alone [13, 14]. Blanc et al. used a boxing game with the Nintendo Wii console and its Wii Sports software for a 15-minute treatment, with a warm-up time of 5 minutes [14]. Klompstra et al. used the same console and software, and played more categories of games (bowling, tennis, baseball, golf and boxing) for 20 minutes of training [13]. These two studies [13, 14] confirmed that VR can be used as an effective method of cardiac rehabilitation to improve the exercise capacity of patients with heart failure (elderly and chronic patients) : the maximum heart rate in VR games is 9% to 16% higher than that in traditional cardiopulmonary rehabilitation, and the exercise time is 1.52 to 3.22 minutes longer [13].

At present, no consensus has been reached on the number of training sessions, the plan of each training session and the application of various techniques, so there are still great differences on the detailed training plan [11]. Weekly workouts range from two sessions per day to three sessions per week, and the total duration of rehabilitation sessions can be up to six months, with sessions ranging from 20 minutes to an hour. But there is consensus that training must be conducted under the supervision of a medical professional.

Current evidence suggests that VR can significantly improve patients' motivation to participate in cardiac rehabilitation (64% of subjects indicated that they would continue to exercise after the study, and 100% of subjects believed THAT VR could be used as a new alternative to cardiac rehabilitation [15]), reduce the dropout rate [16]15] (VR vs control group = 6% vs 19%), Increased training compliance, increased physical activity [17] (6 min walk distance: VR vs control group = 319.9119.3m vs 263.5115.4m, P < 0.02) and energy expenditure [17], and even accelerated recovery and early discharge [17] (length of stay: VR vs control group = 9.410.5 days vs 12.210.9 m, P < 0.02). The limiting factors for home VR training include limitations in motion capture and gesture recognition (91%) and lack of home space (27%) [15]. The most recent randomized preliminary study confirmed that VR therapy significantly reduced depressive symptoms (16% reduction in the depression portion of the Hospital Anxiety and Depression Scale (HADS), P = 0.01) and anxiety (23% reduction in the depression portion of the Hospital Anxiety and Depression Scale (HADS)) among CAD patients who received VR. P = 0.003) and stress level (perceived Stress Questionnaire (PSQ) score decreased by 12.8%, P = 0.03).

4 conclusion

In cardiac rehabilitation, virtual reality technology is considered as an alternative to traditional cardiac rehabilitation training, and can be combined alone or with traditional cardiac rehabilitation. Even though there is no consensus on the prescription of VR training, its benefits in cardiac rehabilitation can significantly improve patients' anxiety and depression in addition to improving patients' enthusiasm and compliance, improving exercise ability and reducing the length of hospital stay.

The resources

1.British Heart Foundation, European cardiovascular disease statistics 2012. 2012.

2.Balady, G.J., et al., Referral, enrollment, and delivery of cardiac rehabilitation/secondary prevention programs at clinical centers and beyond: a presidential advisory from the American Heart Association. Circulation, 2011. 124(25): p. 2951-2960.

3.Dalal, H.M., P. Doherty, and R.S. Taylor, Cardiac rehabilitation. British Medical Journal, 2015. 351: p. h5000.

4.Ma, L.-Y., et al., China cardiovascular diseases report 2018: an updated summary. Journal of Geriatric Cardiology, 2020. 17(1): p. 1-8.

5.Servey, J.T. and M. Stephens, Cardiac rehabilitation: improving function and reducing risk. American Academy of Family Physicians, 2016. 94(1): p. 37-43.

6.Balady, G.J., et al., Core components of cardiac rehabilitation/secondary prevention programs: 2007 update: a scientific statement from the American Heart Association Exercise, Cardiac Rehabilitation, and Prevention Committee, the Council on Clinical Cardiology; the Councils on Cardiovascular Nursing, Epidemiology and Prevention, and Nutrition, Physical Activity, and Metabolism; and the American Association of Cardiovascular and Pulmonary Rehabilitation. Circulation, 2007. 115(20): p. 2675-2682.

7.Smith, S.C., Jr., et al., AHA/ACC guidelines for secondary prevention for patients with coronary and other atherosclerotic vascular disease: 2006 update: endorsed by the National Heart, Lung, and Blood Institute. Circulation, 2006. 113(19): p. 2363-2372.

8.Thomas, R.J., et al., AACVPR/ACC/AHA 2007 performance measures on cardiac rehabilitation for referral to and delivery of cardiac rehabilitation/secondary prevention services endorsed by the American College of Chest Physicians, American College of Sports Medicine, American Physical Therapy Association, Canadian Association of Cardiac Rehabilitation, European Association for Cardiovascular Prevention and Rehabilitation, Inter-American Heart Foundation, National Association of Clinical Nurse Specialists, Preventive Cardiovascular Nurses Association, and the Society of Thoracic Surgeons. Journal of the American College of Cardiology 2007. 50(14): p. 1400-1433.

9.Fernández de Bobadilla Osorio, J., et al., Update on preventive cardiology and rehabilitation. Revista Española de Cardiología (English edition) 2012. 65 Suppl 1: p. 59-64.

10.Galve, E., et al., Update in cardiology: vascular risk and cardiac rehabilitation. Revista Española de Cardiología (English edition) 2014. 67(3): p. 203-210.

11.García-Bravo, S., et al., Virtual reality and video games in cardiac rehabilitation programs. A systematic review. Disability Rehabililation, 2021. 43(4): p. 448-457.

12.Chaddha, A., et al., Technology to help promote physical activity. American Journal of Cardiology, 2017. 119(1): p. 149-152.

13.Klompstra, L., T. Jaarsma, and A. Strömberg, Exergaming to increase the exercise capacity and daily physical activity in heart failure patients: a pilot study. BMC Geriatrics, 2014. 14: p. 119.

14.Blanc, P., et al., Effect of the Wii sport boxing video game on the heart rate in cardiac rehabilitation patients. Archives of Cardiovascular Diseases Supplements, 2011. 3(1): p. 87.

15.Vieira, Á., et al., Kinect system in home-based cardiovascular rehabilitation. Proceedings of the Institution of Mechanical Engineers, Part H, 2017. 231(1): p. 40-47.

16.Ruivo, J., et al., In-class active video game supplementation and adherence to cardiac rehabilitation. Journal of Cardiopulmonary Rehabilitation and Prevention, 2017. 37(4): p. 274-278.

17.Cacau Lde, A., et al., The use of the virtual reality as intervention tool in the postoperative of cardiac surgery. The Brazilian Journal of Cardiovascular Surgery, 2013. 28(2): p. 281-289.