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

Table 24-5 ■ COMPARISON OF CLINICAL FEATURES OF HEART FAILURE WITH REDUCED AND PRESERVED
EJECTION FRACTIONS
HF with Reduced LVEF HF with Preserved LVEF
Sex More men than women More women than men
Age (years) 50–60 60
Etiology MI or idiopathic DCM HTN
DM, AF
Clinical progress Persistent HF Often episodic HF
c LV volumes

0
LV hypertrophy
/
Desynchronize Common Less common
Mitral inflow pattern RFP or ARP ARP
Peak mitral annular systolic velocity Greatly reduced Moderately reduced
Peak mitral annular early diastolic velocity Greatly reduced Moderately reduced
LA pressure Elevated Elevated
LA volume Elevated Normal
f
AF, atrial fibrillation; ARP, abnormal relaxation pattern; DCM, dilated cardiomyopathy; HTN, hypertension; DM, diabetes; LA, left atrium; RFP, restricted filling pattern; MI,
f
myocardial infarction.
Adapted from Sanderson, J. E. (2007). Heart failure with a normal ejection fraction. Heart, 93(2), 155–158. Table 1.

delayed ventricular relaxation most commonly due to distortion During the past 20 years, the role of diastolic dysfunction has
of the ventricular chamber and prolongation of the ventricular been increasingly recognized. The different pathophysiologic
ejection. Advances in imaging of the myocardium both with processes behind systolic and diastolic dysfunction affect progno-
echocardiograms and functional MRI have led to increased un- sis and treatment and are addressed in the following sections. 20
derstanding of the factors that lead to diastolic dysfunction.
Qualitatively, ventricle walls are thick, there is an increase in left Left-Sided HF
atrial (LA) size and reduction in mitral annulus motion. 36 LA Left-sided HF, associated with elevated pulmonary venous pressure
volume is often viewed as a morphologic expression of LV dias- and decreased cardiac output, appears clinically as breathlessness,
tolic dysfunction. When the mitral valve is open during diastole, weakness, fatigue, dizziness, confusion, pulmonary congestion, hy-
the LA is exposed to the loading pressures of the LV. As the LA is potension, and death.
chronically exposed to the increased filling pressure of LV, re- Weakness or fatigue is precipitated by decreased perfusion to
modeling occurs and results in increased LA size and volume. 39 the muscles. Abnormalities of skeletal muscle histology and
The LV has passive compliance or elastic property that charac- biochemistry also play a role, along with deficient endothelial
terizes wall stiffness. Diastolic function can be impaired by four function. Patients describe a feeling of heaviness in their arms
types of lusitropic abnormalities: slowed relaxation with decreased and legs, and there is a reduction in exercise capacity. Cardiac
t
P
P
rate of pressure fall (–dP/dt) during isovolumetric relaxation, de- cachexia is a severe complication of HF and is considered a ter-
layed filling during early diastole, incomplete relaxation with re- minal manifestation. Circulating cytokines are known to be im-
duced filling throughout diastole, and decreased compliance or portant in tissue catabolism.
increased stiffness in late diastole. These changes cause abnormal Decreased cerebral perfusion caused by low cardiac output leads
pressure–volume relationships and produce a higher pressure for to changes in mental status, such as restlessness, insomnia, night-
any given volume. The pressure is transmitted backwards to the mares, or memory loss. Anxiety, agitation, paranoia, and feelings of
atria, and the pulmonary, and systemic circulation, as noted by el- impending doom may develop as the syndrome progresses.
evated pulmonary pressures and decreased cardiac output, leading During the course of HF, pulmonary congestion progresses
to dyspnea and fatigue during exercise. 7 through three stages: stage 1, early pulmonary congestion; stage 2,
27
LV failure is caused by diastolic dysfunction in up to 40% of interstitial edema; and stage 3, alveolar edema. During the early
cases. The etiology is most commonly secondary to long-standing phase, little measurable increase in interstitial lung fluid is noted.
systemic hypertension, but CAD; diabetes; obesity; sleep disor- There are few clinical manifestations during this phase.
ders; hypertrophic, infiltrative, and restrictive cardiomyopathies; Interstitial edema usually occurs when the PAWP exceeds
and primary valve disorders also can lead to diastolic HF. 20 Pure 18 mm Hg, leading to a net filtration of fluid into the interstitial
diastolic dysfunction has also been observed immediately after space. Clinical manifestations of interstitial edema are varied.
20
cardiac surgery. Changes that occur in the cardiovascular system Engorged pulmonary vessels, elevated PA pressure, and reduced
as a result of aging have a greater impact on diastolic function lung compliance cause increased exertional dyspnea. 22 If LV
than on systolic function. Consistency of the association of female function is severely impaired, orthopnea or a nonproductive
sex with HF and preserved LV function across numerous sub- cough may be present. Paroxysmal nocturnal dyspnea may also
groups of patients implies that sex itself is an important determi- occur because of postural redistribution of blood flow that in-
nant of LV adaptation, regardless of the underlying pathophysio- creases venous return and pulmonary vascular pressure when the
logic process. 40,41 The major consequence of diastolic failure patient is in a recumbent position. Congestion of the bronchial
relates to elevation of ventricular filling pressures, causing pul- mucosa that increases airway resistance and the work of breath-
monary and/or systemic congestion. ing may also contribute to paroxysmal nocturnal dyspnea.