Chapter 13 Cardiac Rehabilitation Flashcards
CARDIAC REHAB
Under the broadened scope of the recent AHRQ guidelines, CR may include exercise programs, ________ and risk factor modification for secondary prevention, and psychosocial counseling. CR is indicated after acute MI, coronary ________, and cardiac ________ or in patients with ________ or chronic stable ________. CR improves Vo2max, peripheral O2 extraction, ST depression, exercise tolerance, subjective sense of well-being, and return to work rates. It also lowers BP, resting HR, and myocardial O2 demand.
CARDIAC REHAB
Under the broadened scope of the recent AHRQ guidelines, CR may include exercise programs, education and risk factor modification for secondary prevention, and psychosocial counseling. CR is indicated after acute MI, coronary revascularization, and cardiac transplantation or in patients with CHF or chronic stable angina. CR improves Vo2max, peripheral O2 extraction, ST depression, exercise tolerance, subjective sense of well-being, and return to work rates. It also lowers BP, resting HR, and myocardial O2 demand.
In addition, CR has been shown to improve ________ control and cause favorable lipoprotein changes (reducing TG and elevating HDL levels). Long-term moderate exercise in CR has been demonstrated to increase the quantity of ________ enzymes in “________ twitch” muscle fibers and development of new muscle capillaries. Angiographic studies have shown reduced atherosclerotic lesions in stable angina patients undergoing intensive physical exercise and on low-fat diet over 1 year without lipid-lowering agents (It should be noted that it has been traditionally stated that CR does not raise [improve] anginal threshold, whereas angioplasty and CABG can.) (Fig. 13-1).
In addition, CR has been shown to improve glycemic control and cause favorable lipoprotein changes (reducing TG and elevating HDL levels). Long-term moderate exercise in CR has been demonstrated to increase the quantity of mitochondrial enzymes in “slow twitch” muscle fibers and development of new muscle capillaries. Angiographic studies have shown reduced atherosclerotic lesions in stable angina patients undergoing intensive physical exercise and on low-fat diet over 1 year without lipid-lowering agents (It should be noted that it has been traditionally stated that CR does not raise [improve] anginal threshold, whereas angioplasty and CABG can.) (Fig. 13-1).
Individual trials of CR after MI have not shown a statistically significant lower mortality rate in the CR groups, but a meta-analysis of 22 randomized trials (n = 4,554) has shown a benefit in overall ________ in the CR group (0.80 odds ratio vs. no CR) during a ________-year average post-MI period.
Individual trials of CR after MI have not shown a statistically significant lower mortality rate in the CR groups, but a meta-analysis of 22 randomized trials (n = 4,554) has shown a benefit in overall mortality in the CR group (0.80 odds ratio vs. no CR) during a 3-year average post-MI period.
EPIDEMIOLOGY
In 1997, 1.1 million Americans were diagnosed with acute MI, and 800,000 patients underwent coronary revascularization. Limited data suggest that CR is a cost-effective use of medical care resources; however, only 10% to 20% of appropriate candidates are thought to participate in formal CR programs. In the Medicare claims analysis for hospitalizations during 1997 of over 250,000 persons older than 65 years, CR use was only 13.9% in patients hospitalized for acute MI and 31% in those who underwent CABG. Women, the very elderly, nonwhites, and patients with multiple comorbidities were even less likely to receive CR. Low participation may be due to geographic factors and a failure of physicians to refer patients, particularly the ________ and ________.
EPIDEMIOLOGY
In 1997, 1.1 million Americans were diagnosed with acute MI, and 800,000 patients underwent coronary revascularization. Limited data suggest that CR is a cost-effective use of medical care resources; however, only 10% to 20% of appropriate candidates are thought to participate in formal CR programs. In the Medicare claims analysis for hospitalizations during 1997 of over 250,000 persons older than 65 years, CR use was only 13.9% in patients hospitalized for acute MI and 31% in those who underwent CABG. Women, the very elderly, nonwhites, and patients with multiple comorbidities were even less likely to receive CR. Low participation may be due to geographic factors and a failure of physicians to refer patients, particularly the elderly and women.
PHASES OF CR
Phase I – The inpatient training phase can begin from days ________ to ________ of hospitalization and typically lasts ≈ ________ to ________ weeks. Goals include prevention of the sequelae of immobilization, education and risk factor modification, independent self-care activities, and household distance ambulation on level surfaces. Protocol-limited submaximal stress testing is often done in uncomplicated patients prior to d/c as a guideline for outpatient ADLs and simple household activities.
PHASES OF CR
Phase I – The inpatient training phase can begin from days 2 to 4 of hospitalization and typically lasts ≈1 to 2 weeks. Goals include prevention of the sequelae of immobilization, education and risk factor modification, independent self-care activities, and household distance ambulation on level surfaces. Protocol-limited submaximal stress testing is often done in uncomplicated patients prior to d/c as a guideline for outpatient ADLs and simple household activities.
PHASES OF CR
Phase II – The output training phase starts ________ to ________ weeks post-d/c and typically lasts ________ to ________ weeks. Goals include increasing cardiac ________ (________) capacity and gradually returning to normal activity levels. A functional exercise ________ (ECG stress) test is typically done ________ to ________ weeks of the postcardiac event (which allows time for the formation of a stable scar over the infarcted area) to guide the exercise prescription and determine eligibility for resuming work and sex.
PHASES OF CR
Phase II – The output training phase starts 2 to 4 weeks post-d/c and typically lasts 8 to 12 weeks. Goals include increasing cardiac volume (CV) capacity and gradually returning to normal activity levels. A functional exercise tolerance (ECG stress) test is typically done 6 to 8 weeks of the postcardiac event (which allows time for the formation of a stable scar over the infarcted area) to guide the exercise prescription and determine eligibility for resuming work and sex.
PHASES OF CR
Phase III – The maintenance phase is ideally a lifelong program of home-or gym-based exercise, aimed at ________ or adding onto benefits obtained during phases I and II, generally under minimal or no clinical supervision.
PHASES OF CR
Phase III – The maintenance phase is ideally a lifelong program of home-or gym-based exercise, aimed at maintaining or adding onto benefits obtained during phases I and II, generally under minimal or no clinical supervision.
CARDIAC REHAB
Absolute contraindications for functional stress testing include recent change in resting ________ or serious cardiac ________, unstable ________, acute or worsening ________ dysfunction, uncontrolled HTN, systemic illness, severe aortic stenosis, or severe physical disability precluding treadmill or arm ergometry use. Relative contraindications include hypertrophic cardiomyopathy, electrolyte abnormalities, moderate valvular disease, or significant arterial or pulmonary HTN.
Note: These contraindications for exercise stress testing are similar to the contraindications for CR in general.
CARDIAC REHAB
Absolute contraindications for functional stress testing include recent change in resting ECG or serious cardiac arrhythmias, unstable angina, acute or worsening LV dysfunction, uncontrolled HTN, systemic illness, severe aortic stenosis, or severe physical disability precluding treadmill or arm ergometry use. Relative contraindications include hypertrophic cardiomyopathy, electrolyte abnormalities, moderate valvular disease, or significant arterial or pulmonary HTN.
Note: These contraindications for exercise stress testing are similar to the contraindications for CR in general.
The 2006 Centers for Medicare & Medicaid Services’ expanded coverage for outpatient CR indications include the following:
Acute MI within the preceding ________ months.
________.
Stable ________ pectoris.
Heart ________ repair/replacement.
________ with or w/o stenting.
Heart or lung transplant.
Note: Heart failure is currently not covered by most insurers, although it is recommended in the ACC/AHA Heart Failure Guidelines.
The 2006 Centers for Medicare & Medicaid Services’ expanded coverage for outpatient CR indications include the following:
Acute MI within the preceding 12 months.
CABG.
Stable angina pectoris.
Heart valve repair/replacement.
PCI with or w/o stenting.
Heart or lung transplant.
Note: Heart failure is currently not covered by most insurers, although it is recommended in the ACC/AHA Heart Failure Guidelines.
EXERCISE PRESCRIPTION
The exercise prescription should address the ________, ________, ________, and ________ and ________ of exercise. ________, ________, and rhythmic exercises involving large muscle groups should be emphasized. ________ and resistive exercise are relatively safe in patients with good LV function, but are contraindicated with ________, severe valvular disease, uncontrolled arrhythmias, or peak exercise capacity
EXERCISE PRESCRIPTION
The exercise prescription should address the type, intensity, content, and duration and frequency of exercise. Isotonic, aerobic, and rhythmic exercises involving large muscle groups should be emphasized. Isometrics and resistive exercise are relatively safe in patients with good LV function, but are contraindicated with CHF, severe valvular disease, uncontrolled arrhythmias, or peak exercise capacity
EXERCISE PRESCRIPTION
The exercise content should include ________ phases. The first phase should involve a ________- to ________-minute warm-up. The warm-up should consist of ________ movement and ________ that gradually increase HR to target range. The subtle increase in O2 demand minimizes exercise-related CV complications. The second phase is the ________ or ________ phase and should be a minimum of ________ minutes up to the recommended 30 to 45 minutes of aerobic activity. Finally, the third phase is cooling down and should last anywhere from 5 to 10 minutes. This period involves low-intensity exercise allowing for recovery and dissipation of the heat load. Omitting this phase can result in decrease in venous return, reducing coronary blood flow while myocardial oxygen consumption remains elevated and can cause such complications as hypotension, angina, and ventricular arrhythmias.
EXERCISE PRESCRIPTION
The exercise content should include three phases. The first phase should involve a 5- to 10-minute warm-up. The warm-up should consist of flexible movement and stretching that gradually increase HR to target range. The subtle increase in O2 demand minimizes exercise-related CV complications. The second phase is the conditioning or training phase and should be a minimum of 20 minutes up to the recommended 30 to 45 minutes of aerobic activity. Finally, the third phase is cooling down and should last anywhere from 5 to 10 minutes. This period involves low-intensity exercise allowing for recovery and dissipation of the heat load. Omitting this phase can result in decrease in venous return, reducing coronary blood flow while myocardial oxygen consumption remains elevated and can cause such complications as hypotension, angina, and ventricular arrhythmias.
EXERCISE PRESCRIPTION
Exercise intensity can be determined by a variety of methods, usually by calculating a “target” HR. The AHA method uses 70% to 85% of the maximum attained by stress testing. For young, healthy adults not undergoing formal exercise stress testing, 70% to 85% of (220 – age) can also be used for general exercise prescriptions, which is based on the assumption that 220 is the appropriate maximum for a newborn and that the maximum decreases ≈ ________ bpm/year. This latter formula, however, does not apply after ________. The standard deviation for this equation is 10 to 15 bpm. Since this formula was derived from studies of men, it may overestimate the HR in women. Therefore, it may be more appropriate to measure the peak exercise capacity or the maximum ability of the CV system to deliver O2 to exercising skeletal muscle and its ability to extract O2 from the blood.
EXERCISE PRESCRIPTION
Exercise intensity can be determined by a variety of methods, usually by calculating a “target” HR. The AHA method uses 70% to 85% of the maximum attained by stress testing. For young, healthy adults not undergoing formal exercise stress testing, 70% to 85% of (220 – age) can also be used for general exercise prescriptions, which is based on the assumption that 220 is the appropriate maximum for a newborn and that the maximum decreases ≈1 bpm/year. This latter formula, however, does not apply after MI. The standard deviation for this equation is 10 to 15 bpm. Since this formula was derived from studies of men, it may overestimate the HR in women. Therefore, it may be more appropriate to measure the peak exercise capacity or the maximum ability of the CV system to deliver O2 to exercising skeletal muscle and its ability to extract O2 from the blood.
Peak exercise capacity can be measured clinically by ________ uptake (________), ________ production (________), and minute ventilation via gas analyzers during exercise. Maximal O2 uptake eventually reaches a plateaulike effect despite increasing workload. AT is another index used to estimate exercise capacity. Anaerobic threshold (AT) is defined as the point at which minute ventilation increases disproportionately relative to VO2 (often seen at 60% to 70% of VO2max). AT is an indicator of increase in ________ ________ produced by working muscles and can be used to distinguish cardiac and noncardiac (pulmonary or musculoskeletal) causes of exercise limitation.
Peak exercise capacity can be measured clinically by O2 uptake (VO2), CO2 production (VcO2), and minute ventilation via gas analyzers during exercise. Maximal O2 uptake eventually reaches a plateaulike effect despite increasing workload. AT is another index used to estimate exercise capacity. Anaerobic threshold (AT) is defined as the point at which minute ventilation increases disproportionately relative to VO2 (often seen at 60% to 70% of VO2max). AT is an indicator of increase in lactic acid produced by working muscles and can be used to distinguish cardiac and noncardiac (pulmonary or musculoskeletal) causes of exercise limitation.
The ________ formula calculates a “heart rate zone,” which is the resting HR in the sitting position plus ________% to ________% of (max HR determined by exercise tolerance testing minus resting HR). For deconditioned patients, the exercise program should begin at the lower end of the spectrum (i.e., 40% to 60%) and then increase as fitness improves.
The Karvonen formula calculates a “heart rate zone,” which is the resting HR in the sitting position plus 40% to 85% of (max HR determined by exercise tolerance testing minus resting HR). For deconditioned patients, the exercise program should begin at the lower end of the spectrum (i.e., 40% to 60%) and then increase as fitness improves.
Borg’s RPE scale is particularly useful for ________ ________ patients since denervation of the ________ heart makes HR parameters unreliable. The traditional Borg RPE scale is scored from ________ to ________, where ________ is rated as “somewhat hard” and corresponds with an exercise intensity sufficient to provide training benefits but still allow conversation during exercise. A score of ________ to ________ corresponds to about 60% of max HR; ________ corresponds to 85% of max HR. The Borg scale is probably more psychologic than physiologic, but encourages independence in exercise (i.e., phase III CR) as external monitoring devices are weaned off.
Borg’s RPE scale is particularly useful for cardiac transplant patients since denervation of the orthotopic heart makes HR parameters unreliable. The traditional Borg RPE scale is scored from 6 to 20, where 13 is rated as “somewhat hard” and corresponds with an exercise intensity sufficient to provide training benefits but still allow conversation during exercise. A score of 12 to 13 corresponds to about 60% of max HR; 15 corresponds to 85% of max HR. The Borg scale is probably more psychologic than physiologic, but encourages independence in exercise (i.e., phase III CR) as external monitoring devices are weaned off.
