Page 594 - Cardiac Nursing

LWBK340-c24_p555-594.qxd 30/06/2009 01:43 PM Page 570 Aptara

570 PA R T IV / Pathophysiology and Management of Heart Disease

treatment of the underlying process is the management goal. The
combination of ischemia and LV dysfunction carries a poor prog- Table 24-8 ■ SYSTOLIC DYSFUNCTION
nosis, and it is this patient group that may benefit from revascu- PHARMACOLOGIC THERAPIES
larization by percutaneous coronary intervention techniques
(Chapter 23) or urgent cardiac surgery (Chapter 25). ACE inhibitor: Titrate to target dose as tolerated
Do not use if creatinine 3.0 mg/dL or potassium 5.5 mEq/L
Begin therapy if systolic blood pressure (SBP) 90 mm Hg without
Systolic Dysfunction vasodilator therapy or 80 mm Hg and asymptomatic with other
Coronary heart disease, hypertension, and dilated cardiomyopa- vasodilator therapy
thy are the most commonly identified causes of LV systolic dys- Begin therapy if serum sodium 134 mg/dL
1
function. The writing committee of the ACC/AHA based the Alternative to ACE inhibitor: angiotensin II receptor blocker or hydralazine/
nitrate combination
therapy guidelines on the four stages of evolution of HF (Fig. 24-1). Do not hold vasodilator unless SBP 80 mm Hg or signs/symptoms of
Stage A includes patients who are at high risk for HF but do not orthostasis, mental changes or T urine output
have LV dysfunction. Treatment is aimed at risk factor modifica- IV/oral loop diuretics for volume overload
tion, including management of hypertension, diabetes and lipids, Maintenance dosing versus aggressive dosing with symptoms
cessation of smoking, and counseling to avoid alcohol and illicit Add thiazide diuretic for synergistic response as needed
drugs. Patients are encouraged to exercise on a regular basis. Obe- Add aldosterone antagonist, spironolactone 25 mg qd (or less) for classes III
and IV
sity increases the risk of diabetes and hypertension, and steps
should be taken to promote strategies to maintain optimal weight. -blocker: Titrate to target dose as tolerated
Use in NYHA Classes II and III patients.* May use in NYHA Class I
An angiotensin-converting enzyme inhibitor (ACE-I) is indicated patients with history of myocardial infarction or hypertension. †
in patients with a history of atherosclerotic vascular disease, hy- May use in NYHA Class IV patients* who are euvolemic without significant
pertension, or diabetes. signs/symptoms of volume overload
Stage B includes patients who are asymptomatic but who have Do not initiate therapy if history of bronchospasm, heart block, or sick sinus
syndrome without permanent pacemaker, hepatic failure, overt
LV systolic dysfunction and are at significant risk for HF. All of congestion, symptomatic hypotension
stage A therapies are needed, with the addition of an ACE-I and Digoxin: Dose is based on weight, age, sex, creatinine
-adrenergic blockers unless contraindicated. Valve replacement clearance, and concomitant medication
or repair should be undertaken in patients with hemodynamically Given at a low dose of 0.125 mg qd. Maintain serum digoxin level of 0.8 to
significant valvular stenosis or regurgitation. 2.0 ng/dL
Stage C includes patients with LV dysfunction with current or
previous symptoms and who need to be treated with all measures *Carvedilol (Coreg) is the only -blocker indicated in mild, moderate, and severe HF
and essential hypertension.
used for stages A and B. They should be managed routinely with † Carvedilol (Coreg) is not indicated in NYHA Class I.
four types of drugs: a diuretic, an ACE-I, a -adrenergic blocker
agent, and digitalis. For those patients with an intolerance to ACE
inhibitors, an angiotensin receptor blocker (ARB) can be used.
For those patients with renal insufficiency or angioedema, a hy- to transplantation. Portable devices have been approved by the
dralazine/nitrate combination can be substituted. The use of an FDA (Chapter 26). Low-dose dopamine, dobutamine, or milri-
aldosterone antagonist (i.e., spironolactone) for NYHA Classes III none on an outpatient basis may benefit patients with refractory
and IV symptoms should be considered. Avoid the use of antiar- HF. However, the intermittent or chronic use of these positive
rhythmics, NSAIDs, and most calcium-channel blockers. Cal- inotropic agents remains an area of controversy. All of these
cium-channel blockers are not of proven benefit for patients with agents have been associated with an increase in mortality as a re-
systolic dysfunction and may be harmful. Such risks may not ex- sult of markedly higher occurrences of sudden death. Cardiac
tend to the use of longer-acting calcium-channel blockers (e.g., transplantation plays a role in end-stage patients without con-
amlodipine), which currently are undergoing further evaluation. traindications to this procedure and offers excellent long-term
Nonpharmacologic therapies include a 2 to 3 g sodium diet, en- outcomes. The goal of therapy for those patients not desiring or
couragement of physical activity with possible referral for cardiac eligible for cardiac transplantation is symptom relief. End-of-life
rehabilitation and exercise training, and administration of in- considerations deserve attention for this patient population as
fluenza and pneumococcal vaccines. well, with the focus of hospice care extending to the relief of
Stage D includes patients with refractory end-stage HF. They symptoms.
should be treated with all measures used for stages A, B, and C.
An overview of the specific pharmacologic therapy for systolic Diastolic Dysfunction
dysfunction is described in Table 24-8. It is critical in this group Several myocardial disorders are associated with diastolic dysfunc-
of patients to have meticulous control of fluid retention. Patients tion, including restrictive, infiltrative, and hypertrophic car-
who are at the end stage of their disease are at particular risk for diomyopathy. The affects of aging that occur in the cardiovascu-
hypotension and may be able to tolerate only a small dose of ACE lar system have a greater impact on diastolic function than on
inhibitors or -blockers, or they may not be able to tolerate them systolic performance. HF associated with preserved systolic func-
at all. Despite optimal treatment, some patients do not improve. tion is predominantly a disease of older women, most with hy-
For these patients, specialized treatment strategies include me- pertension and LV hypertrophy. In contrast to systolic dysfunc-
chanical circulatory support, continuous inotropic therapy, refer- tion, there are few studies on therapy for diastolic dysfunction. 45
ral for cardiac transplantation, or hospice care. The difference in pharmacologic therapy is that the goal of drug
Circulatory support may include LV assistance devices therapy in diastolic dysfunction is to reduce symptoms by lower-
1
(LVADs) or extracorporeal devices. For patients who cannot be ing the elevated filling pressures without significantly reducing
sustained on medical therapy, LVAD has been a successful bridge cardiac output (Table 24-9). The treatment of HF caused by