Page 743 - Cardiac Nursing

LWBK340-c29_p705-721.qxd 6/30/09 12:04 AM Page 719 Aptara Inc.

C HAP TE R 2 9 / Acquired Valvular Heart Disease 719

in adults has been largely abandoned and is reserved for only those ventricle is forced to pump the normal volume received from the
candidates unsuitable for surgery (i.e., older adults with heart fail- left atrium as well as the regurgitant volume from the aorta.
ure or pregnant women). Similar to mitral regurgitation, the hemodynamic presentation
and the heart’s ability to compensate differ depending on whether
Aortic Valve Replacement the aortic insufficiency is acute or chronic. In chronic aortic re-
Aortic valve replacement should be considered the treatment of gurgitation, the left ventricle is subjected to pressure and volume
choice for severe aortic stenosis in spite of age. 39 Aortic valve re- overload. As a result, the left ventricle develops mild concentric
placement for mechanical relief of obstruction to flow is the only hypertrophy to accommodate the pressure load and eccentric hy-
40
effective treatment. The natural history of aortic stenosis is used pertrophy to compensate for the increased volume load. Patients
as a guide to determine the timing of aortic valve replacement sur- with chronic aortic regurgitation may remain asymptomatic for
gery. Patients with asymptomatic aortic stenosis have nearly the years, until progressive left ventricular dilation and dysfunction
same survival rate as the age-matched general population. Once result in CHF. In patients with acute aortic regurgitation, the left
the patient experiences symptoms of angina, syncope, or heart ventricle has not had time to compensate with either concentric
failure, there is an abrupt decline in survival rate. In patients pre- or eccentric hypertrophy and cannot accommodate the large vol-
senting with CHF, only 50% survive 2 years. For patients who ume caused by acute aortic regurgitation. As a result, left ventric-
present with syncope, the 3-year survival rate is only 50% without ular and left atrial pressures rise sharply, causing acute CHF and
aortic valve replacement. The average life expectancy of patients pulmonary edema. Patients with acute aortic regurgitation usually
with apnea is only 5 years without aortic valve replacement. 41 require surgical intervention.
Aortic valve replacement is recommended in all patients with se-
vere, symptomatic aortic stenosis. Selection of aortic valve pros- Clinical Manifestations
theses is discussed earlier in this chapter.
Patients with chronic aortic regurgitation are often asymptomatic
for many years. Common symptoms of aortic regurgitation include
AORTIC INSUFFICIENCY fatigue and exertional dyspnea. Patients may report palpitations,
dizziness, and the sensation of a forceful heartbeat, especially when
Cause lying on their left side. Angina may also be noted, but it occurs less
frequently in aortic regurgitation than in aortic stenosis. As heart
Aortic regurgitation may be caused by either intrinsic abnormali- failure ensues, patients experience orthopnea, paroxysmal nocturnal
ties of the aortic valve leaflets or disease of the aortic root. In rheu- dyspnea, and cough related to left-sided heart failure. With acute
matic fever and endocarditis, the aortic leaflets are directly af- aortic regurgitation, symptoms of left-sided heart failure develop
fected. In congenitally bicuspid valves, the larger cusp may rapidly.
become redundant, resulting in diastolic prolapse and progressive
aortic regurgitation. The aortic valve may also become incompe- Physical Assessment
tent because of aortic root dilation. As the aortic root dilates, the
aortic annulus becomes so large that the valve cusps no longer ap- The typical murmur of aortic regurgitation is a high-pitched, early
proximate, resulting in regurgitation. diastolic decrescendo murmur with a blowing quality (see Table 29-
Aortic root dilation is seen in patients with Marfan syndrome, 2). Patients also may have a physiologic murmur of mitral stenosis
rheumatic arthritis, ankylosing spondylitis, annuloaortic ectasia caused by the regurgitant aortic jet, which partially prevents mitral
(associated with hypertension and aging), aortic dissection, valve closure (Austin Flint murmur). As the severity of aortic regur-
syphilitic aortitis, and collagen vascular disease. gitation increases, the murmur becomes louder and longer. In
chronic aortic regurgitation, the point of maximal impulse is dis-
Pathology placed laterally. Systolic hypertension and decreased diastolic pres-
sure create a widened pulse pressure. Patients with chronic aortic
Rheumatic fever leads to fibrinous infiltrates on the valve cusps, regurgitation may have a host of other physical findings that may
causing them to contract and become malaligned and incompe- not be present in acute aortic regurgitation (Table 29-6).
tent. Patients with rheumatic disease may have a “mixed lesion”
that includes both aortic regurgitation and aortic stenosis. In
acute or subacute infective endocarditis of the aortic valve, tissue Table 29-6 ■ SPECIFIC PHYSICAL EXAMINATION FINDINGS
destruction of the leaflets causes cusp perforation or prolapse. IN AORTIC REGURGITATION
Vegetations adherent to the aortic valve may also interfere with
valve closure, causing incompetence. In patients with aortic root Sign Physical Description
dilation or ascending aortic dissection, the aortic annulus becomes Quincke’s sign Pulsatile flushing/blanching of nail bed with
greatly enlarged, the aortic leaflets separate, and aortic incompe- application of gentle pressure
tence follows. de Musset’s sign Bobbing of head with each pulse
Corrigan’s pulse Sharp systolic upstroke and diastolic collapse of pulse
(waterhammer)
Pathophysiology Müller’s sign Bobbing of uvula with each pulse
Traube’s sign “Pistol shot” sound auscultated over the femoral
Volume overload occurs secondary to regurgitant volume reenter- arteries
ing the left ventricle from the aorta through the incompetent aor- Duroziez’s sign Biphasic femoral bruit auscultated with mild pressure
tic valve. Retrograde flow occurs during diastole when left ven- Hill’s sign Blood pressure higher in arms than legs
tricular pressure is low and aortic pressure is high. The left