- Symptoms and signs of heart failure with predominant right-sided findings.
- Normal left and right ventricular size and systolic function with dilated atria.
- Diastolic ventricular functional abnormalities suggestive
of reduced ventricular compliance.
- Increased ventricular filling pressure (left > right) and
reduced cardiac output.
Definitions and Terminology
The World Health Organization defines cardiomyopathies as heart muscle diseases of unknown cause; restrictive cardiomyopathy is
one of three forms (the others are dilated cardiomyopathy and hypertrophic
cardiomyopathy). Restrictive cardiomyopathies are classified as primary
(endocardial fibrosis and eosinophilic endomyocardial disease) or
secondary to cardiac infiltrative diseases. Diseases with a defined
cause that produce a dilated cardiomyopathy with restrictive characteristics
are specifically excluded from this classification of cardiomyopathies.
For the clinician, restrictive cardiomyopathy is usually due to infiltrative diseases, such as the cardiomyopathy that occurs in
systemic amyloidosis, hemochromatosis, sarcoidosis, and glycogen
storage diseases (Table 15–1). These
secondary cardiomyopathies are included because the cardiac involvement
typically displays features of restrictive physiology that are pivotal
in the diagnosis. Restrictive cardiomyopathies represent less than
1% of cases of congestive heart failure, and most of these
are of the secondary form.
Table 15–1. Classification of Restrictive Cardiomyopathy.
| Save Table
Table 15–1. Classification of Restrictive Cardiomyopathy.
|Familial ± skeletal myopathy||Amyloidosis|
|Löffler cardiomyopathy (endocarditis parientalis fibroplastica)|
Glycogen storage diseases
|Tropical endomyocardial fibrosis||Sarcoidosis|
|Chronic allograft rejection|
Also known as diastolic dysfunction and diastolic heart failure, restrictive physiology requires a precise definition, even though clinical methods often yield only indirect evidence of this functional abnormality. It is characterized by elevated filling pressures and impaired ventricular filling from myocardial or endocardial abnormalities in a nondilated ventricle with no significant impairment of systolic performance. Numerous common cardiac diseases can produce
the functional abnormalities of the restrictive or diastolic type, but the diseases are not classified as a restrictive cardiomyopathy.
An alternative term applied to many of these diseases, infiltrative cardiomyopathy emphasizes that the endocardial, interstitial, or
intracellular infiltration of a variety of materials (eg, extensive
collagen bundles, amyloid protein) is the central histologic and
pathophysiologic feature. The infiltration of material with tissue
less compliant than normal myocardium and the increase in the wall
thickness of the cardiac chambers reduce chamber compliance.
This term is sometimes used to describe the reduction in left ventricular chamber volume as the consequence of endocardial fibrosis
and extensive mural thrombus formation.
Abnormalities in Diastolic Function
Although there are several causes of abnormal diastolic function in restrictive cardiomyopathy, loss of ventricular chamber compliance
is the most common. Fibrosis and the presence of amyloid and hemosiderin
all change the intrinsic mechanical properties of the chamber wall.
Furthermore, the rate and extent of myocardial relaxation and elastic
recoil are reduced in restrictive cardiomyopathy, causing increased
diastolic pressures, an increased rate of early diastolic filling,
and a reduced rate of atrial filling. Myocardial ischemia may further
compromise diastolic function. In cardiac amyloidosis particularly,
the coronary arteries may be infiltrated, reducing myocardial blood supply.
Restrictive physiology is best quantified by an assessment of the passive properties of the ventricles, usually of left ventricular
compliance. No routine clinical methods measure chamber compliance, but
a variety of tests are available to assess the consequences of altered chamber
compliance. Specifically, alterations in the pattern of ventricular
filling, absolute filling pressures, and pressure waveforms may
be routinely determined by noninvasive and invasive techniques.
Idiopathic Restrictive Cardiomyopathy
Patients with this condition have hemodynamic findings consistent with restrictive cardiomyopathy and endomyocardial biopsies that
show fibrosis or variable degrees of cellular hypertrophy. The thickness
of the ventricular wall need not be increased.
The average age of these patients at presentation is 20–30 years old. Most patients are women. The clinical course is variable,
with many patients being symptomatically stable for years whereas
others die quickly without cardiac transplantation to treat severe
An idiopathic restrictive cardiomyopathy has also been described in children—predominantly girls—with a mean age
of 4 years. Most were dead within several years of presentation,
suggesting that idiopathic restrictive cardiomyopathy in childhood
has a worse prognosis than in adults.
Sporadic case reports describe restrictive cardiomyopathy in multiple members of families. The coexistence of a skeletal myopathy
has been seen in a family with a dominantly inherited restrictive cardiomyopathy.
In 1936, Löffler described a cardiomyopathy associated with eosinophilia. It is now established that the degree and duration
of eosinophilia quantitatively relate to the extent of endomyocardial
disease. Males are more commonly affected. The disease has different
stages and presentations; the most common is multiorgan involvement,
evidence of a systemic inflammatory response, and thromboembolic events.
Occasionally, it presents as a classic restrictive cardiomyopathy.
Tropical Endocardial Fibrosis
This form of restrictive cardiomyopathy is rarely seen in the industrialized societies of the West but is quite common in subtropical
and tropical regions. Although overt eosinophilia is not the rule,
the gross and microscopic features of the disease resemble those
of Löffler cardiomyopathy. Overt manifestations of heart
failure with ascites and edema frequently emerge in late childhood
and early adulthood. The scarring process usually involves both
ventricles, producing restrictive hemodynamics, although isolated
right and left ventricular involvement occasionally occurs. The
early stages of the disease have not been well characterized.
Management is unlike that for other causes of restrictive cardiomyopathy, and
endocardiectomy may produce significant clinical improvement.