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CARDIAC SYSTEM
49
Table 1-18. American Ilearr Association's Functional Capacity and Objective Assessment of Patients with Diseases or the Heart Functional Clpacitt
Objective Assessmentb
Class I: Patiems with cardiac disease but without
No objective evidence of
resulting limitations of physical activity. Ordicardiovascular disease
nary physical activity does nOt cause undue
fatigue, palpitation, dyspnea, or anginal pain.
Class II: Patients with cardiac disease thar results
Objective evidence of
m a slight limitation of physical activity.
minimal cardiovascular
Paricnr� are comforrable at rest, but ordinary
disease
physical activity results in fatigue, palpitations, dyspnea, or anginal pam.
Class III: Patients with cardiac disease that
Objective evidence of
results 111 a marked limitation of physical
moderately severe caractivity. I>atienrs arc comforrable at rest, but
diovascular disease
less-than-ordinary activity causes fatigue, palpitations, dyspnea, or angmal pam.
Class IV: Patlenrs with cardiac disease [hat
Objective evidence of
results in an inability to carry on any physical
severe cardiovascular
activit), Without discomfort. Fatigue, palpitadisease
tions, dyspnea, or .,mglllal palll may be presenr
even at rest. If any physical activiry is undertaken, symptoms increase.
�F""cliu".,l cap,JClty refers to subjective symptoms of the paflenr. This aspect of the
classification is idenncal lo the New York Heart Association's Classification.
"Ob;ectwe ,lssessmem was added to the claSSification system by the American 'Ieart
Assouauon In 1994. II refers 10 measurements such as electrocardiograms, stress tests,
ech()(ardiogram�. and radiologic Images."l
Functional Classification of Heart Disease, and this new classification is
described in Table 1 - 1 8. Activity progression for patients hospitalized
with CHF is based on the ability of medical treatments (e.g., dillresis, inotropes) to keep the patient Out of heart failure. When a patient with CHF
is medically stabilized, the CHF is thought to be "compensated." Clinical
examination findings allow the therapist to continuously evaluate the
patient'S tolerance to the activity progression. Although metabolic equivalent (MET) tables are nOt commonly used clinically, they do provide a method of progressively increasing a patient'S activity level. As greater
MET levels are achieved with an appropriate hemodynamic response, the
next level of activity can be attempted. Table 1 - 1 2 provides MET levels
for common activities that can be performed with patients.
50
AClITE CARE HANDBOOK FOR PHYSICAL THERAPISTS
Management
The following section discusses surgical and nonsurgical procedures,
pharmacologic interventions, and physical therapy interventions for
patients with cardiac dysfunction.
Revascu/arization and Reperfusion of the Myocardium
Thrombolytic Therapy
Thrombolyric therapy has been established as an acute management
strategy for patients experiencing an M1 because of the high prevalence
of coronary artery thrombosis during acute Mis. Thrombolytic agents,
characterized as fibrin-selective and nonselective agents, are administered
to appropriate candidates via intravenous access. The most common
agents include: streptokinase (nonselective), anisylated plasminogen
streptokinase activator complex (nonselective), and tissue plasminogen
activator (t-PA) (fibrin-selective)." Fibrin-selective agents have a high
velocity of clot lysis, whereas the nonselective agents have a slower clot
lysis and more prolonged systemic lyric state.
The indication for thrombolytic therapy includes chest pain that is
suggestive of myocardial ischemia and is associated with acute ST segment elevation on a 1 2-lead ECG or a presumed new left ventricular bundle branch block. Hospital protocol regarding the time period to perform thrombolyric therapy usually varies, as clinical trials have led to some controversy.12 Some studies show benefits only if treaanent is conducted within 6 hours of symptoms, whereas others have demonstrated improvement with treatment up to 24 hours after onset of symptoms. 12
The contra indications to thrombolytic therapy generally include
patients who are at risk for excessive bleeding. Because of the variability that can occur among patients, many contraindications ate considered relative caurions, and the potential benefits of therapy are
weighed against the potential risks. Thtombolytic therapy is used in
conjunction with other medical treatments such as aspirin, intravenous heparin, intravenous nitroglycerin, lidocaine, atropine, and a beta-blocker. As previously discussed, early peaking of CK-MB is
associated with reperfusion.'2
Percutaneous Revascularization Procedures
Percutaneous revascularization procedures are used to return blood
flow through coronary arteries that have become occlusive secondary
CARDIAC SYSTEM
5 1
to atherosclerotic plaques. The following list briefly describes three
percutaneous revascularization proceduresl2:
1 . PerClltalleOllS translumillal corollary allgioplasty (PTCA)
is performed on small atherosclerotic lesions that do not completely occlude the vessel. PTCA can be performed at the time of an initial diagnostic catheterization, electively at some time after a
catheterization, or urgently in the setting of an acute Ml.
A sheath is inserted into the femoral, radial, or brachial artery,
and a catheter is guided through the sheath into the coronary
artery. A balloon system is then passed through the catheter to the
lesion site. Inflations of variable pressure and duration may be
arrempted to reduce the lesion by at least 20% diameter with a
residual narrowing of less than 50% in the vessel lumen 12 Owing
to some mild ischemia that can occur during the procedure,
patients occasionally require temporary transvenous pacing, intraaortic ballon counterpulsation, or femorofemoral cardiopulmonary bypass circulatory suppOrt during PTCA.
The use of coronary laser angioplasty, directional coronary
atherectomy, and endoluminal stents was developed in response to
the major limitations of PTCA, which include abrupt closure (in
up to 7.3% of patients), restenosis, anatomically unsuitable
lesions, chronic total occlusions, unsatisfactory results in patients
with prior coronary arrery bypass graft (CABG) surgery '·
2.
Coronary laser angioplasty uses laser energy to create precise