Rating Schedule

SYMPTOMATIC LIMITATION

In this section reference is made to limitation of activities of daily living because of symptoms. Information about such limitation is subjective, and it is open to interpretation on the part of both patient and examiner. Therefore, when it is possible, the examiner should obtain objective data about the extent of the limitation before attempting to estimate the degree of permanent impairment. When estimating the extent of a limitation due to symptoms, the physician should use the functional classification in Table 1.

TABLE

FUNCTIONAL CLASSIFICATIONS

EXERCISE TESTING

In most circumstances the physician should attempt to quantitate limitations due to symptoms by observing the patient during exercise. The most widely used and standardized exercise protocols involve the use of a motor-driven treadmill with varying grades and speeds. The protocols vary slightly, but they all attempt to relate the exercise to excess energy expended and to functional class. The excess energy expended usually is expressed with the “MET,” a term that represents the multiples of resting metabolic energy utilized for any given activity. One MET is considered to be 3.5 ml(kg.min). The 70kg person who burns 1.2 kilocalories per minute sitting at rest uses approximately 3 METs when walking 4 kilometers per hour.

Table 2 displays the relationship of excess energy expenditures in METs to functional class according to the protocols of several investigators. With all the protocols, the exercise periods last for three minutes; the periods are represented in the table by boxes with numbers giving the estimated METs involved.

If a treadmill is not available, steps may be used to attempt to quantitate the exercise capacity of a patient. Table 3 shows the relationships of exercise with steps of various heights, excess energy expenditure, and functional class. Estimations of excess energy expenditure also can be made with a bicycle ergometer (Table 4).

Some laboratories are equipped to measure oxygen consumption and carbon dioxide production during exercise. Data on a patient acquired by these techniques may become the most accurate method of estimating a patient’s exercise capacity.

A major problem with using any exercise-testing technique to attempt to quantitate an individual’s functional capacity is the marked variability in the patient’s abilities and willingness to cooperate. Therefore, the physician also must estimate the individual’s cooperation and effort during the test; some patients will continue far beyond where they should, while others will stop after minimal effort because they feel fatigued.

VALVULAR HEART DISEASE

The severity of valvular heart disease can be reduced, but not fully reversed, by operative procedures on the valves or by replacement of the valve with a prosthetic device. After such a procedure, sufficient time from the date of operation must elapse to allow maximum recovery of the heart, lungs, and other organs before estimating permanent impairment due to valvular disease.

In addition, medications may affect the severity of valvular heart disease, especially limitations due to symptoms. Therefore, sufficient time must be allowed for these medications to be introduced and adjusted, and for them to exert their effects, before an estimate of permanent impairment is made.

Impairment Classification for Valvular Heart Disease

Class 1—Impairment of the Whole Person, 1—14%

The patient has evidence by physical examination or laboratory studies of valvular heart disease but no symptoms in the performance of ordinary daily activities or even upon moderately heavy exertion (functional class 1);

and

The patient does not require continuous treatment, although prophylactic antibiotics may be recommended at the time of a surgical procedure to reduce the risk of bacterial endocarditis;

and

The patient remains free of signs of congestive heart failure; and there are no signs of ventricular hypertrophy or dilation, and the severity of the stenosis or regurgitation is estimated to be mild;

or

In the patient who has recovered from valvular heart surgery, all of the above criteria are met.

Class 2—Impairment of the Whole Person, 15—29%

The patient has evidence by physical examination or laboratory studies of valvular heart disease and there are no symptoms in the performance of ordinary daily activities, but symptoms develop on moderately heavy physical exertion (function class 2);

or

The patient requires moderate dietary adjustment or drugs to prevent symptoms. The patient has signs or laboratory evidence of cardiac chamber hypertrophy and/or dilation, and the severity of the stenosis or regurgitation is estimated to be moderate, and surgical correction is not feasible or advisable;

or

The patient has recovered from valvular heart surgery and meets the above criteria

Class 3—Impairment of the whole person, 30-54%

The patient has signs of valvular heart disease and has slight to moderate symptomatic discomfort during the performance of ordinary daily activities (functional class 3);

and

Dietary therapy or drugs do not completely control symptoms or prevent congestive heart failure;

and

The patient has signs or laboratory evidence of cardiac chamber hypertrophy or dilation, the severity of the stenosis or regurgitation is estimated to be moderate or severe, and surgical correction is not feasible;

or

The patient has recovered from heart valve surgery but continues to have symptoms and signs of congestive heart failure, including cardiomegaly.

Class 4—Impairment of the whole person, 55-95%

The patient has signs by physical examination of valvular heart disease, and symptoms at rest or in the performance of less-than-ordinary daily activities (functional class 4);

and

Dietary therapy and drugs cannot control symptoms or prevent signs of congestive heart failure;

and

The patient has signs or laboratory evidence of cardiac chamber hypertrophy and/or dilation; and the severity of the stenosis or regurgitation is estimated to be moderate or severe, and surgical correction is not feasible;

or

The patient has recovered from valvular heart surgery but continues to have symptoms or signs of congestive heart failure.

CORONARY HEART DISEASE

Impairment due to coronary heart disease can be reduced, but not eliminated by diet, exercise training programs, cessation of cigarette smoking, use of medication, and surgical procedures. Sufficient time must be allowed for these measures to have an effect before an estimate of permanent impairment is made.

Impairment Classification for Coronary Heart Disease

Class 1—Impairment of the Whole Person, 0—14%

Because of the serious implications of reduced coronary blood flow, it is not reasonable to classify the degree of impairment as 0% to 10% in any patient who has symptoms of coronary heart disease corroborated by physical examination or laboratory tests. This class of impairment should be reserved for the patient with an equivocal history of angina pectoris in whom coronary angiography is performed, or for a patient on whom coronary angiography is performed for other reasons and in whom is found less than 50% reduction in the cross-sectional area of a coronary artery.

Class 2-Impairment of the Whole Person, 15—29%

The patient has history of a myocardial infarction or angina pectoris that is documented by appropriate laboratory studies, but at the time of evaluation the patient has no symptoms while performing ordinary daily activities or even moderately heavy physical exertion (functional class 1);

and

The patient may require moderate dietary adjustment and/or medication to prevent angina or to remain free of signs and symptoms of congestive heart failure;

and

The patient is able to walk on the treadmill or bicycle ergometer and obtain a heart rate of 90% of his or her predicted maximum heart rate without developing significant ST segment shift, ventricular tachycardia, or hypotension; if the patient is uncooperative or unable to exercise because of disease affecting another organ system, this requirement may be omitted.

or

The patient has recovered from coronary artery surgery or angioplasty, remains asymptomatic during ordinary daily activities, and is able to exercise as outlined above. If the patient is taking a beta adrenergic blocking agent, he or she should be able to walk on the treadmill to a level estimated to cause an energy expenditure of at least 10 METs as a substitute for the heart rate target.

Class 3—Impairment of the Whole Person, 30—54%

The patient has a history of myocardial infarction that is documented by appropriate laboratory studies, and/or angina pectoris that is documented by changes on a resting or exercise ECG or radioisotope study that is suggestive of ischemia;

or

The patient has either a fixed or dynamic focal obstruction of at least 50% of a coronary artery, demonstrated by angiography;

and

The patient requires moderate dietary adjustment or drugs to prevent frequent angina or to remain free of symptoms and signs of congestive heart failure, but may develop angina pectoris or symptoms of congestive heart failure after moderately heavy physical exertion (functional class 2);

or

The patient has recovered from coronary artery surgery or angioplasty, continues to require treatment, and has the symptoms described above.

Class 4—Impairment of the Whole Person, 55—95%

The patient has history of a myocardial infarction that is documented by appropriate laboratory studies, or angina pectoris that has been documented by changes on a resting ECG or radioisotope study that is highly suggestive of myocardial ischemia;

or

The patient has either fixed or dynamic focal obstruction of at least 50% of one or more coronary arteries, demonstrated by angiography;

and

Moderate dietary adjustments or drugs are required to prevent angina or to remain free of symptoms and signs of congestive heart failure, but the patient continues to develop symptoms of angina pectoris or congestive heart failure during ordinary daily activities (functional class 3 or 4), or there are signs or laboratory evidence of cardiac enlargement and abnormal ventricular function;

or

The patient has recovered from coronary artery bypass surgery or angioplasty and continues to require treatment and have symptoms as described above.

CONGENITAL HEART DISEASE

Impairment Classification for Congenital Heart Disease

Class 1-Impairment of the Whole Person, 0—14%

The patient has evidence by physical examination or laboratory studies of congenital heart disease and has no symptoms in the performance of ordinary daily activities, or even upon moderately heavy physical exertion;

and

Continuous treatment is not required, although prophylactic antibiotics may the recommended after surgical procedures to reduce the risk of bacterial endocarditis; and the patient remains free of signs of congestive heart failure and cyanosis;

and

There are no signs of cardiac chamber hypertrophy or dilation; the evidence of residual valvular stenosis or regurgitation is estimated to be mild; there is no evidence of left-to-right or right-to-left shunt; and the pulmonary vascular resistance is estimated to be normal;

or

In the patient who has recovered from corrective heart surgery, all of the above criteria are met.

Class 2-Impairment of the Whole Person, 15—29%

The patient has evidence by physical examination or laboratory studies of congenital heart disease, has no symptoms in the performance of ordinary daily activities, and has no symptoms with moderately heavy physical exertion (functional class 2);

or

The patient requires moderate dietary adjustments or drugs to prevent symptoms or to remain free of signs of congestive heart failure or other consequences of congenital heart disease, such as syncope, chest pain, emboli, or cyanosis;

or

There are signs or laboratory evidence of cardiac chamber hypertrophy or dilation, or the severity of valvular stenosis or regurgitation is estimated to be moderate; or there is evidence of a small residual left-to-right or right-to-left shunt; or there is evidence of moderate elevation of the pulmonary vascular resistance, which should be less than one- half the systemic vascular resistance;

or

The patient has recovered from surgery for the treatment of congenital heart disease and meets the above criteria for impairment.

Class 3—Impairment of the Whole Person, 30—54%

The patient has evidence by physical examination or laboratory studies of congenital heart disease and experiences symptoms during the performance of ordinary daily activities(functional class 3);

and

Diet modification and drugs do not completely control symptoms or prevent signs of congestive heart failure;

and

There are signs or laboratory evidence of cardiac chamber hypertrophy or dilation; or the severity of valvular stenosis or regurgitation is estimated to be moderate or severe; or there is evidence of a right-to-left shunt; or there is evidence of a left-to-right shunt with the pulmonary flow being greater than two times the systemic flow; or the pulmonary vascular resistance is elevated to greater than one-half the systemic vascular resistance;

or

The patient has recovered from surgery for the treatment of congenital heart disease but continues to have functional class 3 symptoms, or continues to have signs of congestive failure or cyanosis, and there is evidence of cardiomegaly and significant residual valvular stenosis or regurgitation, left-to-right shunt, right-to-left shunt, or elevated pulmonary vascular resistance.

Class 4—Impairment of the Whole Person, 55—95%

The patient has signs of congenital heart disease and experiences symptoms of congestive heart failure at less than ordinary daily activities (functional class 4);

and

Dietary therapy and drugs do not prevent symptoms or signs of congestive heart failure;

and

There is evidence from physical examination or laboratory studies of cardiac chamber hypertrophy or dilation, or the pulmonary vascular resistance remains elevated at greater than one-half of the systemic vascular resistance; or the severity of the valvular stenosis or regurgitation is estimated to be moderate to severe; or there is a left-to-right shunt with the pulmonary flow being greater than two times the systemic flow; or there is a left-to-right shunt with the pulmonary vascular resistance being elevated to greater than one-half the systemic vascular resistance; or there is a right-to-left shunt;

or

The patient has recovered from heart surgery for the treatment of congenital heart disease and continues to have symptoms or signs of congestive heart failure causing impairment as outlined above.

HYPERTENSIVE CARDIOVASCULAR DISEASE

In the patient in whom a diagnosable disorder causes the hypertension, estimation of permanent impairment should not be undertaken until adequate time has elapsed after treatment of the disorder. If other organs are affected, as with the kidneys in chronic renal disease, then the degree of impairment due to the hypertension should be combined with that due to the other organ system, using the Combined Values Chart.

Drugs are now available with acceptable side effects that can maintain blood pressure in the normal range in most patients with primary hypertension and in most with secondary hypertension and no correctable cause. Ratings of impairment due to hypertension should be delayed until after the drugs have been prescribed and their doses have been adjusted to achieve maximum effect.

Before classifying a patient as having hypertensive cardiovascular disease, the physician should make several determinations of the arterial pressure. Hypertensive cardiovascular disease is not necessarily present when a patient exhibits transient or irregular episodes of elevated arterial pressure; these could be associated with an emotional or environmental stimulus or with signs or symptoms of cardiovascular system hyperactivity. Most authorities agree that hypertensive cardiovascular disease is present when the diastolic pressure is repeatedly in excess of 90 mm Hg.

Impairment Classification for Hypertensive Cardiovascular Disease

Class 1—Impairment of the Whole Person, 0—14%

The patient has no symptoms and the diastolic pressures are repeatedly in excess of 90mm Hg;

and

The patient is taking antihypertensive medications but has none of the following abnormalities: (1) abnormal urinalysis or renal function tests; (2) history of hypertensive cerebrovascular disease; (3) evidence of left ventricular hypertrophy; (4) hypertensive vascular abnormalities of the optic fundus, except minimal narrowing of arterioles.

Class 2—Impairment of the Whole Person, 15—29%

The patient has no symptoms and the diastolic pressures are repeatedly in excess of 90mm Hg;

and

The patient is taking antihypertensive medication and has any of the following abnormalities: (1) proteinuria and abnormalities of the urinary sediment, but no impairment of renal function as measured by blood urea nitrogen (BUN) and serum creatinine determinations; (2) history of hypertensive cerebrovascular damage; (3) definite hypertensive changes in the retinal arterioles, including crossing defects and old exudates.

Class 3—Impairment of the Whole Person, 30—54%

The patient has no symptoms and the diastolic pressure readings are consistently in excess of 90 mm Hg;

and

The patient is taking antihypertensive medication and has any of the following abnormalities: (1) diastolic pressure readings usually in excess of 120 mm Hg; (2) proteinuria or abnormalities in the urinary sediment, with evidence of impaired renal function as measured by elevated BUN and serum creatinine, or by creatinine clearance below 50%; (3) hypertensive cerebrovascular damage with permanent neurological residual; (4) left ventricular hypertrophy according to findings of physical examination, ECG, or chest radiograph, but no symptoms, signs, or evidence by chest radiograph of congestive heart failure; or (5) retinopathy, with definite hypertensive changes in the arterioles, such as “copper or silver wiring,” or A-V crossing changes, with or without hemorrhages and exudates.

Class 4—Impairment of the Whole Person, 55-95%

The patient has a diastolic pressure consistently in excess of 90 mm Hg;

and

The patient is taking antihypertensive medication and has any two of the following abnormalities:

(1) diastolic pressure readings usually in excess of 120 mm Hg; (2) proteinuria and abnormalities in the urinary sediment, with impaired renal function and evidence of nitrogen retention as measured by elevated BUN and serum creatinine or by creatinine clearance below 50%; (3) hypertensive cerebrovascular damage with permanent neurological deficits; (4) left ventricular hypertrophy; (5) retinopathy as manifested by hypertensive changes in the arterioles, retina, or optic nerve; (6) history of congestive heart failure;

or

The patient has left ventricular hypertrophy with the persistence of congestive heart failure despite digitalis and diuretics.

CARDIOMYOPATHIES

Cardiomyopathies result in impairment of the whole person by causing abnormal ventricular function. Abnormal ventricular function may not result in abnormal hemodynamics, or it may result in pulmonary and/or systemic organ congestion and decreased cardiac output. Abnormal ventricular functions related to coronary heart disease, valvular heart disease, and hypertensive heart disease are covered in their respective sections. Cardiomyopathies may also cause arrhythmias; these are considered in a different section of this chapter. Some cardiomyopathies are reversible. Every effort should be made to identify the reversible forms and to treat them appropriately over an adequate period of time before estimating any suspected permanent impairment.

Impairment Classification for Cardiomyopathies

Class 1—Impairment of the Whole Person, 0—14%

The patient is asymptomatic and there is evidence of impaired left ventricular function from clinical examination or laboratory studies;

and

There is no evidence of congestive heart failure or cardiomegaly from physical examination or laboratory studies.

Class 2—Impairment of the Whole Person, 15—29%

The patient is asymptomatic and there is evidence of impaired left ventricular function from physical examination or laboratory studies;

and

Moderate dietary adjustment or drug therapy is necessary for the patient to be free of symptoms and signs of congestive heart failure;

or

The patient has recovered from surgery for the treatment of hypertrophic cardiomyopathy and meets the criteria above.

Class 3—Impairment of the Whole Person, 30-54%

The patient develops symptoms of congestive heart failure on greater than ordinary daily activities (functional class 3) and there is evidence of abnormal ventricular function from physical examination or laboratory studies;

and

Moderate dietary restriction or the use of drugs is necessary to minimize the patient’s symptoms, or to prevent the appearance of signs of congestive heart failure or evidence of it by laboratory study;

or

The patient has recovered from surgery for the treatment of hypertrophic cardiomyopathy and meets the criteria described above.

Class 4—Impairment of the Whole Person, 55—95%

The patient is symptomatic during ordinary daily activities despite the appropriate use of dietary adjustment and drugs, and there is evidence of abnormal ventricular function from physical examination or laboratory studies;

or

There are persistent signs of congestive heart failure despite the use of dietary adjustment and drugs;

or

The patient has recovered from surgery for the treatment of hypertrophic cardiomyopathy and meets the above criteria.

PERICARDIAL HEART DISEASE

It is important to allow adequate time for resolution of an acute illness, and for medical or surgical therapy to be effective before assessing permanent impairment.

Impairment Classification for Pericardial Disease

Class 1—Impairment of the Whole Person, 0—14%

The patient has no symptoms in the performance of ordinary daily activities or moderately heavy physical exertion but does have evidence from either physical examination or laboratory studies of pericardial heart disease;

and

Continuous treatment is not required, and there are no signs of cardiac enlargement or of congestion of lungs or other organs;

or

In the patient who has had surgical removal of the pericardium, there are no adverse consequences of the surgical removal and the patient meets the criteria above.

Class 2—Impairment of the Whole Person, 15—29%

The patient has no symptoms in the performance of ordinary daily activities but does have evidence from either physical examination or laboratory studies of pericardial heart disease;

but

Moderate dietary adjustment or drugs are required to keep the patient free from symptoms and signs of congestive heart failure;

or

The patient has signs or laboratory evidence of cardiac chamber hypertrophy or dilation;

or

The patient has recovered from surgery to remove the pericardium and meets the criteria above.

Class 3—Impairment of the Whole Person, 30—54%

The patient has slight to moderate discomfort in the performance of greater than ordinary daily activities (functional class 2) despite dietary or drug therapy, and the patient has evidence from physical examination or laboratory studies of pericardial heart disease;

and

Physical signs are present, or there is laboratory evidence of cardiac chamber enlargement, or there is evidence of significant pericardial thickening and calcifications;

or

The patient has recovered from surgery to remove the pericardium but continues to have the symptoms, signs, and laboratory evidence described above.

Class 4—Impairment of the Whole Person, 55—95%

The patient has symptoms on performance of ordinary daily activities (functional class 3 or 4) in spite of using appropriate dietary restrictions or drugs, and evidence from physical examination or laboratory studies of pericardial heart disease;

and

The patient has signs or laboratory evidence of congestion of the lungs or other organs;

or

The patient has recovered from surgery to remove the pericardium and continues to have symptoms, signs, and laboratory evidence described above.

ARRHYTHMIAS

Arrhythmias tend to fluctuate remarkably in the frequency with which they occur. Thus, adequate documentation of the arrhythmia and estimation of the frequency with which it occurs must be made. The associated symptoms may be considerably different from the symptoms of other forms of heart disease. Arrhythmias may cause syncope, palpitation, dizziness, light headedness, chest heaviness, or shortness of breath or combinations of these symptoms.

The degree of impairment from cardiac arrhythmias often will have to be combined with the degree of impairment due to an underlying heart disease; this combining should be done according to the Combined Values Chart. After instituting therapy for the arrhythmias, one should allow an appropriate amount of time to pass before estimating the extent of the permanent impairment.

Impairment Classification for Cardiac Arrhythmias

Class 1—Impairment of the Whole Person, 0—14%

The patient is asymptomatic during ordinary activities and a cardiac arrhythmia is documented by ECG;

and

There is no documentation of three or more consecutive ectopic beats or periods of asystole greater than 1.5 seconds, and both the atrial and ventricular rates are maintained between 50 and 100 beats per minute;

and

There is no evidence of organic heart disease.

Class 2—Impairment of the Whole Person, 15—29%

The patient is asymptomatic during ordinary daily activities and a cardiac arrhythmia is documented by ECG;

and

Moderate dietary adjustment, or the use of drugs, or an artificial pacemaker, is required to prevent symptoms related to the cardiac arrhythmia;

or

The arrhythmia persists and there is organic heart disease.

Class 3—Impairment of the Whole Person, 30—54%

The patient has symptoms despite the use of dietary therapy or drugs or of an artificial pacemaker and a cardiac arrhythmia is documented with ECG;

but

The patient is able to lead an active life and the symptoms due to the arrhythmia are limited to infrequent palpitations and episodes of lightheadedness or other symptoms of temporarily inadequate cardiac output.

Class 4—Impairment, 55—95%

The patient has symptoms due to documented cardiac arrhythmia that are constant and interfere with ordinary daily activities (functional class 3 or 4);

or

The patient has frequent symptoms of inadequate cardiac output documented by ECG due to frequent episodes of cardiac arrhythmia;

or

The patient continues to have episodes of syncope that are either due to or have a high probability of being related to the arrhythmia. To fit into this category of impairment, the symptoms must be present despite the use of dietary therapy, drugs, or artificial pacemakers.

If an arrhythmia is a result of organic heart disease, the arrhythmia should be evaluated separately and its impairment rating should be combined with the impairment rating for the organic heart disease using the Combined Values Chart.

VASCULAR DISORDERS OF THE UPPER EXTREMITY

When amputation due to peripheral vascular disease is involved, the impairment due to amputation should be evaluated and combined using the Combined Values Chart.

Impairment of the Upper Extremity Due to Peripheral Vascular Disease

Class 1—Impairment of Upper Extremity, 0—5%

The patient experiences neither intermittent claudication nor pain at rest;

and

The patient experiences only transient edema;

and

On physical examination, not more than the following findings are present: loss of pulses, minimal loss of subcutaneous tissue of fingertips; calcification of arteries as detected by radiographic examination; asymptomatic dilation of arteries or of veins, not requiring surgery and not resulting in curtailment of activity.

or

Raynaud’s phenomenon that occurs with exposure to temperatures lower than 0°C (32°F) but is readily controlled by medication.

Class 2—Impairment of Upper Extremity, 6—24%

The patient experiences intermittent claudication on severe usage of the upper extremity;

or

There is persistent edema of a moderate degree, incompletely controlled by elastic supports;

or

There is vascular damage evidenced by a sign such as a healed, painless stump of an amputated digit showing evidence of persistent vascular disease, or a healed ulcer;

or

Raynaud’s phenomenon occurs on exposure to temperatures lower than 4°C (39° F). but is controlled by medication.

Class 3—Impairment of Upper Extremity, 25—50%

The patient experiences intermittent claudication on moderate upper-extremity usage;

or

There is marked edema that is only partially controlled by elastic supports;

or

There is vascular damage evidenced by a healed amputation of two or more digits of one extremity, with evidence of persisting vascular disease or superficial ulceration;

or

Raynaud’s phenomenon occurs on exposure to temperatures lower than 10°C (50°F), and it is only partially controlled by medication.

Class 4—Impairment of Upper Extremity, 51—79%

The patient experiences intermittent claudication on mild upper-extremity usage;

or

The patient has marked edema that cannot be controlled by elastic supports;

or

There is vascular damage as evidenced by signs such as an amputation at or above an ankle, or amputation of two or more digits of two extremities with evidence of persistent vascular disease, or persistent widespread or deep ulceration involving one extremity.

Class 5—Impairment of Lower Extremity, 80—95

The patient experiences severe and constant pain at rest;

or

There is vascular damage as evidenced by signs such as amputations at or above the ankles of two extremities, or amputation of all digits of two or more extremities, with evidence of persistent vascular disease or of persistent, widespread, or deep ulceration involving two or more extremities.

VASCULAR DISORDERS OF THE LOWER EXTREMITY

When amputation due to peripheral vascular disease is involved, the impairment due to amputation should be evaluated and combined with the appropriate value using the Combined Values Chart

Impairment of Lower Extremity Due to Peripheral Vascular Disease

Class 1—Impairment of Lower Extremity, 0—5%

The patient experiences neither claudication nor pain at rest;

and

The patient experiences only transient edema;

and

On physical examination, not more than the following findings are present: loss of pulses; minimal loss of subcutaneous tissue; calcification of arteries as detected by radiographic examination; asymptomatic dilation of arteries or of veins, not requiring surgery and not resulting in curtailment of activity.

Class 2—Impairment of Lower Extremity, 6—24%

The patient experiences intermittent claudication on walking at least 100 yards at an average pace;

or

There is persistent edema of a moderate degree, incompletely controlled by elastic supports;

or

There is vascular damage as evidenced by a sign, such as that of a healed, painless stump of an amputated digit showing evidence of persistent vascular disease, or of a healed ulcer.

Class 3—Impairment of Lower Extremity, 25—50%

The patient experiences intermittent claudication on walking as few as 25 yards and no more than 100 yards at average pace;

or

There is marked edema that is only partially controlled by elastic supports;

or

There is vascular damage as evidenced by a sign such as healed amputation of two or more digits of one extremity, with evidence of persisting vascular disease or superficial ulceration.

Class 4—Impairment of Lower Extremity, 51 —79%

The patient experiences intermittent claudication on walking less than 25 yards,

or

the patient experiences intermittent pain at rest;

or

The patient has marked edema that cannot be controlled by elastic supports;

or

There is vascular damage as evidenced by signs such as an amputation at or above an ankle, or amputation of two or more digits of two extremities with evidence of persistent vascular disease, or persistent widespread or deep ulceration involving one extremity.

Class 5—Impairment of Lower Extremity, 80—95

The patient experiences severe and constant pain at rest;

or

There is vascular damage as evidenced by signs such as amputations at or above the ankles of two extremities, or amputation of all digits of two or more extremities, with evidence of persistent vascular disease or of persistent, widespread, or deep ulceration involving two or more extremities.