- After the impact of coronary heart disease (CHD) on people’s lives was recognized by researchers, health professionals began to work harder to prevent or delay its progression.
- Cardiac rehabilitation is the general name for an organized program for people who have heart disease or are trying to prevent it, and has become popular in the last 20 years.
Risk Factors
a)Static
- b) Dynamic risk factors are divided into two.
- a) Static (Nonmodified) risk factors:
1- Age
2- Sex
3- Family history or heredity
- b) Dynamic (modified) risk factors:
1- elevation of serum lipids
2- diet
3- hypertension
4- smoking
5- carbohydrate tolerance deficiency
6- obesity
7- sedentary life
8- personality
9- stress
Age:
Although the onset of the atherosclerotic process of CAD occurs early in life, the clinical manifestations of the disease appear with advancing age.
The Framingham heart study in 1964 showed that men aged 50-59 years were four times more at risk than men aged 30 years.
CAD is the leading cause of death in men after the age of 40 and women after the age of 55. The 12-year Framingham heart study found that age was the most important risk factor when risk factors were evaluated individually.
Sex
The 18-year Framingham Heart Study has shown that men are three times more at risk than women, and cardiovascular disease occurs 10-20 years later in women than in men.
Family history
Studies have shown that lipid deposition on the intima of the artery is a genetic phenomenon, but lifestyle and environmental conditions also influence this risk factor.
Increased serum lipids
Since cholesterol is the primary lipid component of the atherosclerotic lesion, elevated blood cholesterol levels are a risk factor for CAD.
This conclusion has been proven in several studies in all countries as well as in the U.S.A. Blood cholesterol levels are related to genetic factors, but can also be controlled by diet.
Lipoproteins are divided into 3 main groups:
- a) VLDL: Very low density lipoproteins
- b) LDL: Low density lipoproteins (the main carrier of cholesterol and positively associated with the presence of CAD.
- c) HDL: High-density lipoproteins (HDL levels have been found to increase in some people after alcohol, smoking and exercise.
Patients with elevated LDL and trglycerides can reduce their risk of CAD by lowering blood sugars, losing weight and reducing alcohol consumption.
Hypertension
Hypertension, whether systolic or diastolic, is a risk factor for the development of CAD.
People of middle age or older, blacks, obese people, heavy smokers and women taking oral contraceptives are particularly prone to essential hypertension.
Although hypertension is easy to diagnose, often patients who are diagnosed do not receive appropriate treatment. Treatment of all forms of hypertension (mild, moderate, severe) is believed to reduce the risk of CAD.
Tobacco
Laboratory studies have shown that smoking increases the development of atherosclerosis, thus provoking the development of myocardial infarction.
Smoking also affects heart rate, blood pressure and the likelihood of arrhythmias.
The risk of death is 1.7 times higher in smokers than in non-smokers.
It is a modifiable risk factor and ceases to be a risk factor in smokers who quit smoking.
Poor tolerance to carbohydrates
Hyperglycemia, whether a subclinical elevation of blood glucose or insulin-dependent diabetes, is a major risk factor for the development of CAD.
Its association with obesity, hypertension and elevated blood lipid levels is also important.
When controlled, its importance as a risk factor decreases.
Obesity
Obesity alone is unlikely to be a risk factor, but it is often associated with other risk factors such as diabetes, hypertension and elevated blood lipid levels, thus increasing a person’s susceptibility to CAD.
It is not clear whether obesity increases the risk of developing atherosclerosis.
Weight control is not the same as controlling hypertension, diabetes and hyperlipidemia.
Sedentary lifestyle
Studies have found that regular isotonic exercise protects people from developing CAD and increases the survival of patients with myocardial infarction.
Regular exercise is thought to reduce myocardial oxygen demand.
In addition, regular exercise reduces other risk factors associated with sedentary living.
Personality
The personality type that increases the development of CAD is the type of personality seen in ambitious, aggressive, impatient and hard-working people called (type A).
Although this has been proven in the studies, it is not known to what extent personalities with this personality can be modified and how much this can change the CAD risk rate.
Stress
It has been determined that a person in a stressful environment is at greater risk than a person working in a calm and relaxed environment.
Stress increases the risk of developing CAD by frequently causing risk factors such as hypertension, smoking and increased blood lipids.
Environmental conditions
Various researchers have determined that environmental conditions such as air pollution, temperature and water hardness can be risk factors in the development of CAD.
The International Heart and Lung Institute determined the 3 most important risk factors in 1971 as;
1- Increased serum cholesterol level
2- Hypertension
3- Smoking
. Of these 3 factors;
A person with 1 present is at 2 times the risk of others,
A person with 2 present is at 4 times the risk of others,
A person with 3 present is at 8 times the risk of others,
Precautions
1- Reducing or stopping smoking
2- Controlling hypertension
3- Correcting eating habits (diets low in salt and cholesterol, adjusting total calories according to body weight, focusing on vegetables and fruits, limiting alcohol, not drinking more than 2 cups of coffee per day, etc.)
4- Regular physical activities (regular walking and moderate intensity exercises every day, also swimming, cycling, running, dancing, etc.)
5- Trying to get out of Type A personality
6- Staying away from stressful conditions
Pathophysiology of coronary artery disease
- Coronary artery disease is an atherosclerotic event and manifests itself with one or more of 4 clinical syndromes:
1- Angina pectoris
2- Myocardial infarction
3- Heart failure
4- Sudden death
Atherosclerotic lesions
Atherosclerosis is a condition in which the thickness of the arterial intima is reduced by lipids It is a progressive disease characterized by thickening of the arterial wall and changes in the arterial structure and functional capacity.
The intima layer of the vascular wall is primarily affected by atherosclerosis.
In the media, some secondary changes occur as the atheromatous plaques extend into it, the wall weakens and probably localized dilatation or aneurysm formation occurs. These lesions are examined in 3 parts.
1- Lipid lines
Lipids are mainly cholesterol, cholesterol ester, phospholipids and natural oils. It is a matter of debate whether this lesion progresses and becomes a fibrotic lesion or is reversible.
2- Fibrous plaque
The rising fibrous plaque is the characteristic lesion of atherosclerosis. This lesion is green-gray in color and thickens by rising in clusters and begins to fill the vascular lumen.
Collagen matrix, elastin and connective tissue cells surround the plaque and form a fibrous space on it.
Most pathologists believe that this plaque is irreversible, but some think that the progression is slow.
3- Complicated plaques
The presence of fibrous plaques with one or more pathological changes such as calcification, necrosis, internal hemorrhage, rupture of the plaque or thrombus formation.
The rough surface of the complicated plaque prepares the ground for platelet aggregation, fibrin deposition or clot formation.
The clot covers the vessel lumen and leads to complete occlusion of the artery or to embolism and ischemia by occlusion of smaller and distal vessels.
If ischemia continues for a long time, infarction may occur.
Symptoms in coronary patients are usually associated with 70% occlusion of the coronary artery lumen.
Cardiac Rehabilitation
Cardiac rehabilitation is a multiphasic program that includes the physiological, psychological and social aspects that regulate the entire life of the patient with coronary heart disease (CHD).
The rehabilitation team consists of the Director (doctor or exercise physiologist), rehabilitation nurse, physiotherapist, exercise physiologist, occupational therapist, psychologist, social worker and health educators.
Cardiac rehabilitation program has; exercise therapy, physiological assessment, vocational assessment, patient education, behavior regulation, diet program, smoking and stress regulation components.
Components of the exercise program;
A physical exercise program should be in 3 parts;
1- warm-up ex. 5-10 min.
2- work phase ex. 20-60 min.
3- cool-down 5-10 min.
- Warm-up period
The exercise program starts with 10-15 minutes of moderate intensity, calisthenic and stretching exercises. The purpose of the warm-up exercises; to increase circulation and body temperature, thus providing oxygen to the muscle tissue and facilitating the effect of muscle contraction.
A proper warm-up gradually increases the work of the heart, reducing the possibility of ST segment depression that may occur during exercise. These exercises also increase joint flexibility and prevent possible skeletal muscle injuries.
Warm-up exercises should be performed in accordance with their purpose and in a sufficient manner, and on the other hand, they should be performed in a way that does not exceed the pulse limits and does not strain the heart.
Gradually increasing the effort also increases coronary circulation, which reduces the risk of myocardial ischemia that can occur with sudden intense exercise.
All major muscle groups should be exercised during the warm-up, and the areas with weakness should be protected.
2- Work Phase
The important components of the work phase are intensity, duration and frequency. An effective and reliable exercise program depends on these.
Direct observation and continuous ECG control of the patient are recommended during the program. For example; rhythm disorders do not occur during the exercise test, but may occur during continuous monitoring.
Blood pressure measurements should also be checked regularly in the meantime.
- A) INTENSITY
The intensity of the workout program is determined by the percentage of functional aerobic capacity, which is best measured by measuring oxygen uptake (VO2). The effect of a suitable workout program is revealed by using VO2 max. between 60% and 80%. Exercise performed with a performance above 80% may cause an additional burden and may be dangerous for cardiac patients.
In many cases where oxygen uptake cannot be calculated, pulse can be used. (The relationship between pulse and oxygen uptake is used.
For example; 57%-79% maximal aerobic functional capacity is equal to 70-80% of maximum heart rate.
Exercise intensity is usually determined by looking at Target heart rate and metabolic equivalents (METs).
a1) Target heart rate
After a person’s maximal heart rate is determined by exercise test, 70-85% of it is considered maximum for the workout program.
For example; the heart rate of a patient with a maximum heart rate of 180 should be between 126 (70% of 180) and 150 (85% of 180) for the workout program.
Another method to determine the target heart rate more accurately has been described by Karvonan.
Accordingly, Target heart rate = (maximum functional heart rate – resting heart rate) + resting heart rate is found by the method.)
For example;
Maximum heart rate = 150
A patient with a resting heart rate = 72;
TRH = (150-72) (70%) + 72 = 127 and
(150-72) (85%) + 72 = 137.
Although these formulas are used, the heart rate during workout varies depending on age and physical condition.
For example; a heart rate of 130 is 65% of the maximum heart rate of a 20-year-old man and 85% of the maximum heart rate of a 60-year-old man.
a2) Metabolic equivalents (METs)
METs determination is another method in organizing an exercise program. In standardized exercise protocols, the functional capacity to be determined and the work done are measured by oxygen consumption.
These oxygen values can be converted to METs. In a person lying supine at rest, oxygen uptake is 3.5 ml per kilogram of body weight per minute (IMETs = 3.5 ml/kg/min)
Bruce protocol
(Determination of VO2 max required for submaximal exercise test)
GROUP EQUATION
Sedentary male VO2(ml/kg/min)=(2.94xmin time)+8.33
Cardiac male VO2(ml/kg/min)=(2.36xmin time)+10.16
Working male VO2(ml/kg/min)=(4.326xmin time)-4.66
Normal female VO2(ml/kg/min)=(2.74xmin time)+8.05
MaxMETs=VO2/(3.5ml/kg)min(1 METs)
- B) DURATION
Dynamic exercise should continue for a long enough time to stimulate aerobic energy against anaerobic energy pathways.
Reducing exercise intensity requires that the exercise be performed for a longer period of time. The effect of a suitable exercise program occurs with 15-20 minutes of work at 60-80% of aerobic capacity, and the effect increases if this period is increased to 20-30 minutes, which is the most appropriate period.
Intermittent program consists of high intensity exercise between 3-5 minutes followed by lower intensity exercise workouts.
For example; walking on a treadmill at 3.5 mph with a 2.5% incline for 4 minutes, then walking on a treadmill with a 0 incline for 1 minute.
This technique is not preferred in the beginning stages of the exercise program, because it requires more intense work.
Intermittent work has several advantages over continuous work.
1- Less fatigue is felt with more work
2- Since the repetition is timed, lactic acid accumulation decreases.
3- Physiological needs are less.
4- Alternating upper and lower extremity exercises can be more interesting and fun.
- C) FREQUENCY
The frequency of exercise is related to its duration and intensity
It is generally recommended to do 3-4 days a week. Aerobic capacity (VO2 max) increases the more the exercise is done.
However, exercises done more than 5 times a week can be dangerous.
Static Exercises
Since static exercises use less muscle and there is not much body movement, they use less circulating oxygen than dynamic exercises.
At the same time, since the muscles are tense, there is less blood flow into the muscle. Thus, with increasing blood pressure, the amount of blood pumped by the heart increases slightly and the heart works harder to reduce the increased resistance.
This causes the heart muscle to need more oxygen. This increased oxygen demand can be tolerated by healthy individuals, but it cannot be tolerated in patients with CAD, especially those with left ventricular dysfunction.
Effects of static exercise
In normal individuals;
1- Heart rate increases
2- Systemic vascular resistance increases
3- Blood pressure increases
4- Stroke volume does not change
5- Cardiac output increases slightly.
In cardiac patients
1- Heart rate increases
2- Systemic vascular resistance increases
3- Blood pressure increases
4- Stroke volume decreases slightly
5- Cardiac output increases slightly or does not change
Dynamic exercises
Dynamic exercises that involve the movement of large muscle groups increase oxygen demand, muscle cells require additional oxygen.
The oxygen transport system is stimulated and thus cardiac output and respiration increase, heart rate and stroke volume increase. Working muscles receive blood at a greater rate than the amount of blood in circulation.
This is made possible by vasodilation of working muscles and vasoconstriction of non-working muscles and organs.
While there is a 30% oxygen requirement at rest, tissues can use 70% oxygen during maximal exercise.
Exercises that involve arm movements generally require more systolic blood pressure, heart rate and oxygen requirement than the same exercises done in the legs.
Effects of dynamic exercises
1- Heart rate increases
2- Systolic blood pressure increases
3- Diastolic blood pressure does not change or decreases
4- Cardiac output increases
5- Coronary blood flow increases
6- Blood flow in non-working muscles decreases
Functional classification of VO2 max and METs relationships
Functional class 4
Feeling of discomfort with any activity
Symptoms may be present at rest
3.5-7.0 ml/kg/min
1-2 METs
Functional class 3
Significant limitation
Comfort at rest
7.5-15 ml/kg/min
2-3.5 METs
Functional class 2
Mild limitation
Some symptoms in activities
15.5-24.5 ml/kg/min
4-6 METs
Functional class 1
No limitation
No symptoms in activities
>24.5 ml/kg/min
>6 METs
3- Cool-down period
Exersize, it is important to continue with low-intensity walking exercises lasting 5-10 minutes until heart rate, blood pressure return to pre-exercise levels.
Vasodilation occurs during exercise, blood flow increases in active muscles.
If exercise is stopped suddenly, blood continues to flow freely to the extremities and pools form until vasoconstriction occurs again. Then venous return decreases, which leads to hypotension, chest pain and dysarthmia complaints.
(Due to inappropriate blood flow of the brain and heart) Myocardial oxygen demand also increases as a result of the increase in heart rate when venous return is not appropriate.
Relaxation period
After a sufficient cool-down period, an appropriate relaxation period is necessary to complete the exercise program. Since people with myocardial artery disease of type A character do not have a habit of relaxing, relaxation techniques should be taught and followed in such patients.
At the end of relaxation exercises, it should be shown how blood pressure decreases, heart rate, respiratory rate, muscle tension decreases.
Relaxation also helps patients increase their sleeping sickness.
There are various techniques such as Benson’s or Jacobson’s relaxation techniques.
Deep breathing is an important component in all relaxation exercises.
Environmental factors affecting exercise
1- Cold weather
Heart patients have a low tolerance to cold and should definitely avoid exercising outside in the winter.
Low temperature causes peripheral vasoconstriction during rest and exercise.
The body secretes endogenous epinephrine and norepinephrine in an effort to keep its temperature at the same level. Increased peripheral vascular resistance leads to an increase in arterial blood pressure, which increases myocardial oxygen demand and therefore increases the risk of angina.
2- Heat and humidity
While metabolic needs increase with exercise, body temperature also increases. Dilation and vasoconstriction of skin arterioles balance the heat generated and lost.
The primary function of circulation during exercise is to bring oxygen to the working muscles and to distribute the heat generated by these muscles to the skin surface, which normally occurs through sweating. Humidity reduces evaporation and heat loss through sweating.
In hot weather, body temperature increases rapidly in response to exercise, skin vessels dilate and blood flows from the center to the periphery, causing excessive sweating.
As a result of the decrease in central blood flow and stroke volume, heart rate increases in order to maintain cardiac output.
Although cardiac output is initially maintained, stroke volume decreases with increasing workload, thus increasing body temperature.
A decrease in cardiac output and subsequently a decrease in mean arterial blood pressure occur.
Exercise programs should be modified in hot weather when temperatures exceed 27 degrees (80 F) and humidity exceeds 75%.
3- Altitude
People who normally live and exercise in low altitude areas must be careful until they get used to the climate and altitude in high altitude areas.
Depending on the altitude, insomnia, headache, nausea, mental insufficiency, fatigue and difficulty breathing may be experienced.
In a person who adapts to altitude, there is an increase in the amount of red blood cells and hemoglobin. At the same time, capillaries enlarge, compensating for the increase in blood viscosity and reducing the workload of the heart.
4- Air pollution
Photochemical oxidants, especially Ozone, primarily affect the pulmonary system. It reduces maximal and submaximal exercise performance by inhibiting oxygen transfer to the lungs.
Carbon monoxide is the most important air pollution agent that occurs with smoking, industrial waste products and automobile exhaust and has harmful cardiovascular effects.
Low amounts of carbon monoxide are absorbed into the blood and combined with hemoglobin (carboxyhemoglobin) are involved in tissue oxygenation.
Studies have shown that COHB between 2.7% and 4.5% can trigger angina after a mild cardiac effort and increase myocardial ischemia (with a significant ST segment change).
Types of cardiac patients
1- Those undergoing coronary artery bypass surgery (CABG)
2- Myocardial infarction,
3- Pacemaker
4- Valve replacement
5- Those who have had coronary angioplasty
6- Others (+ exercise test, those who have had angina pectoris)
CABG selection criteria
1- Stable angina with a high-grade left main trunk (LMT) lesion
2- Stable angina with CAD involving the terminal vessels
3- Unstable angina with severe CAD involving both vessels or terminal vessels
4- New myocardial infarction with angina
5- Ischemic heart failure (+shock)
Cardiac rehabilitation program
Cardiac rehabilitation program
is examined in 3 major phases
1- Phase I-Inpatient
2- Phase II-Outpatient
3- Phase III-Comminite Programs
(There are also programs examined in 4 or more phases.)
- Inpatient (Phase I) exercise programs
Inpatient exercise program; is a program that starts during the patients’ hospital stay and usually in the coronary intensive care unit (CCU). Those with uncomplicated MI, coronary artery bypass graft (CABG), pulmonary disease or peripheral vascular disease can start the rehabilitation program during their hospital stay.
The inpatient program starts with 1-2 METs at low intensity and is gradually increased to 2-3 METs. Those who have undergone CABG start the program with deep breathing exercises within 12-48 hours of the operation.
In this program, the staff/patient ratio is generally 1/1. The patient is constantly monitored and the appropriate exercise program is decided and the emergency team is always kept ready to prevent complications that may arise.
The purpose of the inpatient program is
1- To provide medical care for the patient
2- To facilitate return to daily physical activities
3- To prevent the physiological and psychological side effects of bed rest
4- To prepare the patient for the later stages of rehabilitation.
CONTRAINDICATIONS for entering the Inpatient and Outpatient programs
1- Unstable angina
2- Resting systolic blood pressure >200 mmHg, diastolic blood pressure >100 mmHg
3- Significant sudden decrease in resting SBP (systolic blood pressure) (20 mmHg or more) unrelated to medications
4- Moderate or severe aortic stenosis
5- Acute systemic disease or fever
6- Uncontrolled atrial or ventricular arrhythmias
7- Uncontrolled tachycardia (more than 100 bpm)
8- Symptomatic congestive heart failure
9- 3rd degree coronary artery block
10- Active pericarditis or myocarditis
11- Thrombophlebitis
12- ST change at rest (more than 3 mm)
13- Uncontrolled diabetes
14- Orthopedic problems preventing exercise
Inpatient Criteria for terminating the exercise program in patients
1- Weakness
2- Inability to monitor
3- Confusion, ataxia, cyanosis, dyspnea, nausea and any peripheral circulatory failure
4- Onset of angina with exercise
5- Symptomatic supraventricular tachycardia
6- ST displacement (greater than 3 mm horizontally or downward)
7- Ventricular tachycardia
8- Left or right bundle branch block induced by exercise
9- Onset of 2nd or 3rd degree heart block
10- Frequent unifocal PVCs (30% larger than the complex)
11- Frequent multifocal PVCs (30% larger than the complex)
12- Increase in resting heart rate of 20 or more times while standing for patients with MI
13- Intense increase in blood pressure; SBP>220, DBP>110 mmHg
14- 10 mmHg or more decrease in SBP
15- Inappropriate bradycardia (without increase in workload)
- Outpatient (Phase II) exercise program
Outpatient phase II program is a program where ideally continuous monitoring is done, emergency team and drugs are prepared and patients are under medical control.
Phase II program starts after the patient is discharged and usually continues for three months.
This program can continue at home as an exercise and walking program and can be done in the form of group treatments in the hospital. The purpose of the Phase II program;
1- Increasing the patient’s physical condition level,
2- Increasing positive lifestyle habits,
3- Getting the patient used to long-term exercise,
In the following cases, it is necessary to be under medical control for the phase II program
1- Low maximal functional capacity
2- Severe depression of left ventricular function
3- Complex ventricular arrhythmias
4- Hypotension caused by exercise
5- Exertional angina (angina caused by movement)
- Home exercise and walking program (phase II)
The patient’s pulse should not exceed 120 and the resting pulse should not exceed +20.
Exercises should be performed at least 3 days a week to a sufficient extent. In uncomplicated patients, these patients are those who do not have heart failure or pain complaints and are generally patients who can perform 14 activity levels.
The home program starts after the patient is discharged and continues for approximately 8-12 weeks until they enter the phase III program.
- Supervised phase II programs
Individuals with functional capacities of 5 METs or more are included in the phase II program. This program includes calisthenic exercises of the upper and lower extremities, as well as treadmill and/or stationary bicycle riding.
Walking on a bicycle or treadmill is programmed better and more specifically than walking at home.
The patient’s progression is also controlled by looking at the monitored pulse, rhythm and blood pressure before and after rest, exercise.
Patients generally continue their exercise programs 3 days a week, and if they have no complaints, they can walk and do their exercises at home every day.
Patients with left ventricular dysfunction should not exercise on their own, but should attend supervised programs 5 times a week.
This program is also useful in controlling dysrhythmias in these patients who are in the recovery period and in understanding whether their medical treatment is appropriate.
Criteria for moving from Phase II to Phase III program
1- Functional capacity > 5 METs
2- Medical status:
Normal hemodynamic responses (blood pressure, ECG, no arrhythmias or stable, no ischemic responses or responding to medications
Stable angina or no angina
Resting heart rate and blood pressure are stable or under control
3- Physical status:
Muscle strength, functional capacity and endurance are normal during daily activities
4- Education:
Basic pathophysiology of cardiovascular diseases,
Information on how long they will take off from their jobs,
Information on the lifestyle that will be suitable for them,
Determination of safety limits in all activities including sexual activities
Phase III – community exercise programs
Phase III program patients are patients who were discharged from the hospital approximately 6-12 weeks ago, have clinically stable angina, arrhythmias that may occur during exercise are controlled with medication and can regulate their exercise levels themselves.
Pulmonary patients and hypertension patients can also benefit from this program frequently. Community programs are conducted in community services.
An effective program requires at least two qualified personnel (e.g., a certified exercise physiologist).
Personnel/patient = 1/10 or more.
All personnel must have worked in CRP. The place where the program is conducted must have everything necessary for emergency events and a team that can come immediately when called. Participants must be able to modify or organize the exercises according to their own conditions.
The exercise program is gradually increased by 50-85% of functional capacity, starting with 45 minutes in the first 3-6 months, 3-4 times a week. When functional capacity reaches 8METs or above, this situation is tried to be maintained.
Although there is no definite procedure for the end of the Phase III program, it ends 6-12 months after discharge.