Cardiac Rehabilitation

Anatomy and Physiology

Cardiac Anatomy

The heart consists of 4 chambers—2 atria and 2 ventricles—enclosed within the pericardial sac. This sac comprises multiple layers—the fibrous, parietal, and visceral (epicardium) pericardium. Between the parietal and visceral layers, up to 50 mL of fluid provides lubrication. The heart consists of 3 layers—the epicardium, myocardium, and endocardium.

The right atrium receives deoxygenated blood, whereas the left atrium receives oxygenated blood. The atrioventricular valves separate the atria from the ventricles, with the tricuspid valve on the right and the mitral valve on the left. The semilunar valves regulate blood flow from the ventricles, with the pulmonary semilunar valve performing this function on the right and the aortic semilunar valve playing the same role on the left. During contraction—which encompasses systole and diastole—the right ventricle pumps deoxygenated blood to the lungs, whereas the left ventricle sends oxygenated blood through the aorta to the systemic circulation.

Effects of Physical Activity on Cardiovascular Physiology

An increase in cardiac output serves as the primary driver of the cardiovascular benefits associated with physical activity and exercise. As cardiac output depends on stroke volume and heart rate, physical activity, especially aerobic exercise, significantly increases both. Enhanced myocardial contractility and greater venous return (preload) contribute to a substantial rise in stroke volume during exercise, alongside an elevated heart rate, further supporting cardiac output.[10]

Long-term exercise promotes beneficial cardiac remodeling, including myocardial hypertrophy and an increased end-diastolic diameter, which enhance myocardial contraction reserve and early diastolic filling, respectively.[11] In addition, exercise positively impacts the vascular system by counteracting age-related vascular remodeling, reducing arterial stiffness, mitigating oxidative stress, preventing inflammation, and lowering blood pressure.[12]

Indications

Cardiac rehabilitation indications include the following:

• Recovery aid after a recent episode of myocardial infarction or acute coronary syndrome
• Symptom management in chronic stable angina cases
• Functional improvement in congestive heart failure cases
• Recovery aid after coronary artery bypass grafting, percutaneous coronary intervention, cardiac transplantation, or valvular surgery
• Long-term management of adult congenital heart diseases [13]

Contraindications

The exercise component of cardiac rehabilitation has specific contraindications, including:

• Unstable angina
• Acute decompensated congestive heart failure
• Complex ventricular arrhythmias
• Severe pulmonary hypertension (right ventricular systolic pressure >60 mm Hg)
• Intracavitary thrombus
• Recent thrombophlebitis with or without pulmonary embolism
• Severe obstructive cardiomyopathies
• Severe or symptomatic aortic stenosis
• Uncontrolled inflammatory or infectious pathology
• Any musculoskeletal condition that prevents adequate participation in exercise [14]

Equipment

The equipment required for cardiac rehabilitation varies by phase. In the early postdischarge phase (approximately 1 week), patients may attend a facility with exercise bicycles, treadmills, strength equipment, and telemetry for monitoring, typically lasting 2 weeks to 1 month. If clinically stable, patients may transition to a nonmedical gym or follow prescribed exercises at home using equipment recommended by healthcare professionals.

Personnel

Cardiac rehabilitation implemented with an interprofessional approach offers well-established benefits.[15][16] The team consists of the following members:

• Patient and family
• Clinicians, particularly specialists such as cardiologists, surgeons, and physiatrists
• Pharmacists
• Nurses
• Physical therapists
• Occupational therapists
• Speech and language pathologists
• Behavioral therapists
• Dietitians
• Case managers

Preparation

Participants begin with a cardiopulmonary exercise assessment to assess their cardiovascular fitness. The rehabilitation team then designs a personalized exercise and education program based on the individual's needs, goals, and fitness level. A gentle warm-up is performed before starting physical rehabilitation.

Technique or Treatment

Cardiac rehabilitation consists of 3 phases: 

• Clinical phase (Phase I): This phase begins in the inpatient setting after a cardiovascular event or intervention. An initial assessment evaluates the patient's physical ability and motivation to tolerate cardiac rehabilitation. Therapists and nurses guide patients through gentle bedside exercises to maintain mobility and prevent hospital-related deconditioning. The rehabilitation team also addresses activities of daily living, educates patients on stress management, and ensures adequate rest during recovery from comorbid conditions or postoperative complications. In addition, patient needs, such as assistive devices, family education, and discharge planning, are carefully evaluated.

• Outpatient cardiac rehabilitation (Phase II): This phase starts once the patient is stable and cleared by cardiology. Phase II typically lasts 3 to 6 weeks, though some programs may extend up to 12 weeks. An initial assessment identifies physical limitations, activity restrictions due to comorbidities, and other barriers to participation. A structured patient-centered therapy plan is developed that includes education, individualized training, and relaxation techniques. This phase aims to promote independence and sustainable lifestyle changes, preparing patients for long-term recovery at home.

• Postcardiac rehabilitation (Phase III): This phase emphasizes independence and self-monitoring, focusing on flexibility, strength, and aerobic conditioning. Patients receive guidance on maintaining an active lifestyle and continuing exercise. Regular outpatient visits with physician specialists help monitor cardiovascular health, adjust medications, and reinforce healthy habits. Interventions may be implemented during this phase to prevent relapse.[17][18]

In surgical cases, a presurgery phase may be attempted, allowing patients to begin cardiovascular rehabilitation before the procedure. However, some studies suggest better tolerance of the postsurgical pathway.

Beyond exercise and physical activity, all phases of cardiac rehabilitation focus on managing medical conditions and cardiovascular risk factors, optimizing nutrition, promoting smoking cessation, and reducing stress. Behavioral health counseling and psychosocial support are also integral components.

Complications

Cardiac rehabilitation includes supervised exercise and physical activity tailored to individual patient needs. The program has a strong safety profile, with a minimal risk of significant cardiovascular complications. A United States study from the early 1980s, analyzing 167 cardiac rehabilitation programs, reported 1 cardiac arrest per 111,996 exercise hours, 1 acute myocardial infarction per 293,990 exercise hours, and 1 fatality per 783,972 exercise hours.[19] Similarly, a French study assessing cardiac rehabilitation safety found a cardiac arrest rate of 1.3 per million patient exercise hours.[20] Rakhshan et al examined heart rhythm device malfunction after 8 weeks of cardiac rehabilitation. The study revealed a reduced incidence of physical complications compared to a control group.[21]

Clinical Significance

Benefits

Cardiac rehabilitation enhances quality of life and reduces healthcare costs.[22] The exercise component provides significant physiological benefits, including increased maximal oxygen uptake (VO₂ max), improved endothelial function, and enhanced myocardial reserve flow. In addition, cardiac rehabilitation supports reductions in smoking, body weight, serum lipids, and blood pressure. Milani et al reported decreased depression in patients with heart disease following a major coronary event.[23] A Cochrane review found that cardiac rehabilitation lowered hospital admissions and contributed to a long-term reduction in all-cause mortality in patients with heart failure and preserved ejection fraction, though no short-term (<12 months) mortality benefit was observed.

Goals

Cardiac rehabilitation goals may be categorized into short-term and long-term objectives. In the short term, the program aims to control cardiac symptoms, enhance functional capacity, mitigate the psychological and physiological impact of cardiac illness, and improve psychosocial and vocational status. Long-term goals focus on altering the natural history of coronary artery disease, stabilizing or reversing atherosclerosis progression, and reducing the risk of sudden death and reinfarction.

Future Research

A systematic review of 19 randomized clinical trials found complex e-coaching to be effective for delivering therapies to improve physical capacity, clinical status, and psychosocial health. However, the review noted a lack of detailed protocols, making it unclear which aspects of e-coaching provide the most benefit and warrant further development. In contrast, basic e-coaching was not found to be effective.[24] In addition, research on cardiac rehabilitation for patients with congenital heart disease remains limited, highlighting the need for randomized clinical trials in adult and pediatric populations to establish specific guidelines based on current evidence.[25]

Enhancing Healthcare Team Outcomes

Despite strong evidence supporting the benefits of cardiac rehabilitation, patient participation remains low. Data from Medicare and the Centers for Disease Control and Prevention indicate that only 14% to 35% of heart attack survivors and approximately 31% of patients post-coronary artery bypass grafting enroll in cardiac rehabilitation or secondary prevention programs. Leon et al identified several factors contributing to low utilization, including low referral rates, lack of insurance coverage, poor patient motivation, and limited program accessibility.[26]

A 2017 qualitative study examining patients' perspectives on cardiac rehabilitation highlighted psychosocial barriers such as lack of time and fear of exercise. Participation was also influenced by prior exercise experience, physiotherapist communication, the severity of cardiovascular disease, and the patient's future goals after rehabilitation. These considerations should inform the development of rehabilitation programs.[27]

An interprofessional cardiac rehabilitation team, including primary care clinicians, cardiologists, cardiovascular surgeons, cardiac nurses, pharmacists, and occupational therapists, can improve patient outcomes. An area that warrants further research is the role of diaphragm muscle rehabilitation in cardiac rehabilitation, as specific guidelines for its implementation remain unclear.[28][29]

Nursing, Allied Health, and Interprofessional Team Interventions

The interprofessional team plays a vital role in cardiac rehabilitation by integrating various healthcare professionals collaborating to deliver comprehensive care. Each team member contributes their expertise to enhance patient recovery, prevent future cardiovascular events, and promote overall health.

Cardiologists oversee cardiovascular health, monitor progress, adjust treatment plans, and provide medical guidance on managing heart conditions. Exercise physiologists design and supervise individualized exercise programs tailored to each patient's fitness level, ensuring safe and effective cardiovascular activity. Nurses educate patients on heart health, medication management, and lifestyle changes while monitoring vital signs during exercise sessions and offering emotional support.

Dietitians develop nutrition plans that support heart health, aid in weight management, and reduce risk factors such as hypertension and high cholesterol. Psychologists and counselors address emotional well-being by helping patients manage stress, anxiety, and depression, which are crucial for adherence to long-term rehabilitation. Physical therapists focus on improving mobility, flexibility, and strength to restore physical function and prevent further complications.

Pharmacists ensure proper medication management, educate patients on prescriptions, and help prevent drug interactions. Social workers assist with resource access, provide emotional support, and help patients overcome social or financial barriers to rehabilitation.

Through this collaborative approach, the team supports patients' physical, emotional, and psychological recovery and optimizes cardiac rehabilitation outcomes. A team-based approach ensures patients receive well-rounded support throughout rehabilitation.

Nursing, Allied Health, and Interprofessional Team Monitoring

Effective monitoring within an interprofessional cardiac rehabilitation team is crucial for ensuring patient safety, tracking progress, and supporting overall well-being during recovery. Each team member contributes to evaluating specific aspects of the patient's health.