Page 552 - Cardiac Nursing

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528 PA R T I V / Pathophysiology and Management of Heart Disease
The treatment is emergency surgical repair preceded by intra-aortic Heart Failure and Cardiogenic Shock
balloon counterpulsation and nitroprusside infusion. The mortality
rate is greater than 20% in 24 hours and 40% in 1 week. Cardiogenic shock, characterized by systemic hypoperfusion due to
low cardiac output despite high filling pressures, complicates ap-
proximately 7% of all cases of acute MI, with the majority resulting
Mitral Regurgitation from LV pump failure. 45,97 The remaining patients with MI who de-
Mitral regurgitation may occur early in the course of acute MI due velop shock do so from mechanical complications, such as ventricu-
to ischemia of the valve or papillary muscles. It occurs most fre- lar septal rupture, mitral regurgitation, or tamponade. Modern ther-
2
quently with inferior MI or non-Q-wave MI. The onset of regur- apy, including aggressive revascularization and intra-aortic balloon
gitant flow is usually within the first week following MI. Diagnosis support, has contributed to an improvement in survival. However,
is made with echocardiography. Pulmonary congestion as a result of the overall 30-day mortality associated with this catastrophic com-
mitral valve dysfunction may be intermittent or persistent. Mitral plication of acute MI remains more than 50% (Chapter 24).
valve dysfunction may require urgent revascularization if the papil-
lary muscle dysfunction is due to ischemia. However, if the ischemic
event causes papillary muscle rupture, ejection fraction declines NURSING MANAGEMENT OF ACS*
rapidly, requiring intra-aortic balloon counterpulsation and the in-
fusion of NTG or sodium nitroprusside before emergency surgical Nursing management of the patient with ACS involves caring for
repair 96 (see Chapter 29). the patient during varying stages of the disease process: During
acute onset of chest discomfort, as the diagnosis is confirmed, at
Arrhythmias hospital discharge, during convalescence, or on an ongoing basis
with the goal to prevent recurrence of angina or MI. The focus of
Arrhythmias can occur in the course of infarction due to electro- this section is on the nursing management of angina pectoris or
physiological alterations in ischemic myocardium, pharma- during the acute phase of MI.
cotherapeutic interventions, electrolyte imbalances, or endoge-
4
nous catecholamine release. Arrhythmias that occur late may be Chest Discomfort
due to poor systolic function or ventricular aneurysm. Ventricu-
lar tachyarrhythmias are not uncommon following MI. Approx- Diagnosis
imately 7% of patients with acute MI have ventricular fibrillation Chest discomfort, related to an imbalance in myocardial oxygen
and cardiac arrest. A similar number of patients experience re- supply and demand, manifested by patient complaints of chest
4
current ventricular tachycardia. Low levels of potassium and discomfort, with or without radiation to arms, neck, back, or jaw,
magnesium can precipitate ventricular fibrillation in this patient by nonverbal expressions of discomfort (facial grimacing, Levine
population and should be monitored closely. Bradyarrhythmias sign), and increases in heart rate, BP, respiratory rate, and by cool,
are more common in inferior wall MI. Sinus bradycardia, sinus clammy skin.
arrest, and second- and third-degree atrioventricular block occur
more commonly in right ventricular (RV) infarction. Complete Goals
heart block occurs up to 20% of all patients with acute RV in-
4
farction. Bradyarrhythmias are treated with atropine or transve- 1. To detect chest discomfort and associated ECG and hemody-
nous pacing. Sinus bradycardia is treated only if the patient is namic changes early.
symptomatic. -Blockers are contraindicated in this setting de- 2.To reduce or eliminate chest discomfort.
spite their clear benefit in MI and angina pectoris. Anterior wall 3. To prevent the occurrence of the discomfort.
MI is much more likely to cause infranodal conduction abnor-
malities, characterized by wide complex idioventricular rhythms 4 Interventions
(see Chapter 16). Nursing interventions are directed toward assessment and im-
provement of the myocardial ischemia. Ischemia can be improved
Pericarditis by interventions that decrease myocardial oxygen consumption or
increase coronary perfusion. Examples of nursing interventions
Pericarditis most commonly occurs as a complication of MI sev- for the hospitalized patient with angina or acute MI follow
eral weeks following the event as a result of a localized inflamma- For Goal 1
tory response. Post-MI, pericarditis is also referred to as Dressler’s
syndrome. Pericarditis can occur acutely following MI, and in Teach the patient to report chest discomfort immediately on a
that case, typically is isolated to the pericardium adjacent to the scale of 1 to 10 (with 10 being the worst) at the onset of the dis-
infarcted area. The diagnosis is made by history, physical exami- comfort and proceed as follows:
nation, and evaluation of the ECG. Typically the patient describes 1. Assess and document the patient’s description of the discom-
sharp, substernal, severe chest pain that can radiate to the neck, fort including location, radiation, duration, intensity, and any
shoulders, or back. The pain is worsened with deep inspiration or factors that exacerbate or improve the discomfort.
when reclining. A pericardial friction rub may be auscultated on 2. Assess BP, heart rate and rhythm, and respiratory rate and rhythm.
physical examination. The classic multilead ST-segment elevation 3. Assess the skin for temperature and moistness.
is present with diffuse pericarditis but not present if the peri- 4. Obtain a 12-lead ECG during chest discomfort.
carditis is localized to the infarct region (Chapter 30). Throm-
bolytic therapy has decreased the incidence of this complication
significantly. 2 *Contributed by Sherri Del Bene and Anne Vaughan.