Page 444 - Cardiac Nursing

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CHAPTER
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E E E E Exercise Testing
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Jonathan Myers
Ex er ci se t es ti ng i wi d, on in va si ve p p 2 2. FFunctional capaacity forr hee purpose of exercise prescriptiion
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Exercise testing iss aa iwiddellyy usedd, noninvasive procedure that pro-
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vides diagnostic, prognostic, and functional information for a 3 3. Exercise capacity forr thee purrpose of work classificationn (disabil-
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wide spectrum of patients with cardiovascullar, pulmonary, and it ityy eevaluation) and risk stratification (proognosis))
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ot otherr disorderss. Grradded exercise tests are usedd to assesss aa patient’s s 4 4. Thee efficacy of m dediccal, surgical, or pharmacologic treatment
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ability to tolerate increased physical activity, while electrocardio- 5.The presence and severity fof arrhythmias
graphic, hemodynamiic, andd symptomatic responses are moni- 6. Preoperative physiologic status
tored in a controlled environment. Graded, progressive exercise 7. Intermittent claudication
can produce abnormalities that are not present at rest, the most
important of which are manifestations of myocardial ischemia, in-
cluding ST-segment changes on the electrocardiogram, symp- SAFETY AND PERSONNEL
toms, and electrical instability. The test is also commonly used to
evaluate other system disorders, such as gas exchange abnormali-
ties in patients with pulmonary disease or chronic heart failure, Provided that contraindications to exercise testing are considered
symptoms associated with peripheral vascular disease, and even and patients who undergo exercise testing are appropriate, the test
neurologic disorders. has been shown to be extremely safe. Widely cited data from the
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In cardiovascular medicine, the exercise test is commonly used Cooper Clinic in Dallas suggest that an event serious enough to
for evaluating the efficacy of medical therapy, for the assessment require hospitalization (e.g., sustained arrhythmia, heart attack, or
of interventions, and as a first-choice diagnostic tool in patients death) occurs at a rate of 0.8 per 10,000 tests. More recent stud-
with suspected coronary artery disease (CAD), a role in which it ies have confirmed the low event rate associated with exercise test-
functions as a “gatekeeper” to more expensive and invasive proce- ing. In a survey of 71 medical centers within the Veterans Affairs
dures. 1,2 In the latter role, the test has become even more impor- Health Care System, an event rate of 1.2 per 10,000 tests was re-
14
tant in the current era of health care cost containment. Although ported. Earlier surveys conducted in the 1970s suggested a
16,17
originally developed as a diagnostic tool, recent studies have es- somewhat higher event rate, ranging from 1 to 4 per 10,000.
tablished the role of the exercise test in the selection of patients for It has been suggested that the apparent improvement in the safety
cardiac transplantation, risk stratification after a myocardial in- of the test reflected in the more recent surveys is due to a signifi-
farction (MI), and the assessment of disability. 3–7 cantly better understanding of when to and when not to perform
Because of the need to standardize the implementation and in- the test, when to terminate the test, and better preparation for any
4,16
terpretation of the exercise test, professional organizations such as emergency that may arise.
the American Heart Association (AHA), the American College of Clinical judgment is the most important consideration when
4
Cardiology (ACC), the American College of Sports Medicine deciding which patients should undergo exercise testing. Con-
3
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(ACSM), the American Thoracic Society, and the European So- traindications to testing usually describe conditions of cardiovas-
9
ciety of Cardiology have developed guidelines designed to opti- cular instability, such as unstable angina, uncontrolled heart fail-
mize the safety, methodology, and objectives of the test. The ure, and arrhythmias. A listing of the absolute and relative
ACSM has developed certification programs for professional com- contraindications to testing is provided in Display 19-1.
petency in exercise testing 8,10 ; ACSM certification has been Historically, professional guidelines have suggested that physi-
strongly recommended for nurses, technicians, or physiologists cian supervision was necessary for all exercise testing in the clini-
who oversee exercise testing in clinical settings. 10–12 This chapter cal setting. Given the remarkable safety record of exercise testing,
14–17
describes the applications, methodology, and principles of exercise particularly in recent years, there is now some debate regard-
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testing for the cardiovascular nurse and the professional standards ing the need for physician supervision for exercise testing. This
for exercise testing described in the aforementioned guidelines. has important implications for nursing because the nurse is fre-
quently the person who prepares the patient and serves as the
technician conducting the test, and in many centers the nurse may
INDICATIONS AND OBJECTIVES supervise the test as a surrogate for the physician. Although the
4
most recent AHA/ACC guidelines continue to recommend
physician supervision when testing patients with heart disease in
The exercise test has numerous indications. Surveys have shown
a clinical setting, the guidelines also state that “. . . exercise testing
that the most common reason patients are referred for exercise
testing is for the evaluation of chest pain 13,14 or, more generally, in selected patients can be safely performed by properly trained
nurses, exercise physiologists, physical therapists, or medical tech-
to assess signs and symptoms of coronary disease. Other common
nicians working directly under the supervision of a physician, who
clinical
the
follo
clinical objectives include the following:wing:
objectiv
include
es
should be in the immediate vicinity and available for emergen-
1. Physiologic response of post-MI and postrevascularization pa- cies.” The ACSM has outlined general guidelines regarding when
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tients to exercise physician supervision is recommended. The nurse, physiologist,
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