AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Background

Restrictive cardiomyopathy (RCM) is a rare disease of the myocardium and is the least-encountered form of cardiomyopathy. RCM accounts for approximately 5% of all cases of primary heart muscle disease. The World Health Organization (WHO) defines RCM as a myocardial disease characterized by restrictive filling and reduced diastolic volume of either or both ventricles with normal or near-normal systolic function and wall thickness. Increased interstitial fibrosis may be present. This disease may be idiopathic or associated with other diseases (eg, amyloidosis, endomyocardial disease with or without hypereosinophilia). The disease course varies depending on the pathology and treatment but is often unsatisfactory. However, the importance of an accurate diagnosis of RCM is to distinguish it from constrictive pericarditis, which also presents with restrictive physiology but is frequently curable by surgical intervention.

RCM closely mimics constrictive pericarditis in its clinical and hemodynamic profile. In the past, the correct diagnosis was frequently not made until surgical inspection demonstrated the pericardium of normal thickness and appearing normal. A subsequent myocardial biopsy would prove the diagnosis of RCM. With the improvement in diagnostic imaging, the necessity of progressing to surgical intervention to confirm the diagnosis of RCM (or constrictive pericarditis) should decrease.

Pathophysiology

This heart muscle disease creates increased stiffness of the myocardium, which causes pressure within the ventricles to rise precipitously with small increases in volume. Thus, accentuated filling occurs in early diastole, which terminates abruptly at the end of the rapid filling phase. When pressure tracings are taken at this point, they show a characteristic diastolic dip and a plateau or a square-root sign.

Patients typically have diastolic heart failure, meaning systolic function is normal, but the left ventricle has increased diastolic stiffness (reduced compliance) and cannot fill adequately at normal diastolic pressures, leading to a reduction in cardiac output due to reduced left ventricular filling volume. Systolic function usually remains normal, at least early in the disease; wall thickness is typically increased secondary to myocardial infiltration with amyloidosis, but it is usually not as pronounced as that observed in hypertrophic cardiomyopathy.

A variable reduction in systolic function may be present as the disease progresses. Reduced left ventricular filling volume leads to reduced stroke volume and low cardiac output symptoms (eg, fatigue, lethargy), whereas increased filling pressures cause pulmonary and systemic congestion. Thus, RCM causes symptoms and signs of left- and/or right-sided failure because it affects both ventricles, but amyloidosis typically presents with dominant right-sided fluid retention.

Some patients may have complete heart block due to fibrosis encasing the sinoatrial or the atrioventricular nodes. Interestingly, amyloid deposition in the bundle branches is rare.

Based on pathology, RCM can be classified as obliterative (ie, thrombus-filled ventricles) or nonobliterative/idiopathic.

Obliterative RCM is very rare. It may result from the end stage of the eosinophilic syndromes, in which an intracavitary thrombus fills the left ventricular apex and hampers the filling of the ventricles. The fibrosis of the endocardium may extend to involve the atrioventricular valves and cause regurgitation. Two forms of endomyocardial fibrosis exist—an active inflammatory eosinophilia and chronic endomyocardial fibrosis.

In idiopathic, or primary, RCM, progressive fibrosis of the myocardium but no thrombus formation occurs. This entity also is said to lack specific histopathologic changes.

Frequency

United States

Idiopathic RCM is observed mainly in the United States.

International

Loeffler endocarditis is common in the temperate zone, and chronic endomyocardial fibrosis is observed in the tropics.

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

History

• Patients usually complain of gradually worsening shortness of breath, progressive exercise intolerance, and fatigue.
• Fatigue and weakness are results of decreased stroke volume and cardiac output.
• Patients may have distention of the abdomen secondary to ascites, but they frequently have profound bilateral peripheral edema.
• Chest pain secondary to angina or chest pain mimicking myocardial ischemia can be observed, primarily in patients with amyloidosis, possibly due to myocardial compression of small vessels.
• Patients may complain of palpitations, frequently due to atrial fibrillation, which is common in idiopathic RCM.
• As many as one third of patients with idiopathic restrictive cardiomyopathy (RCM) may present with thromboembolic complications, especially pulmonary emboli secondary to blood clots in the legs. If atrial fibrillation is present, high risk of left atrial clots and systemic emboli is present.
• Patients may have a history of syncopal attacks from a variety of causes, but orthostatic hypotension secondary to a peripheral and/or autonomic neuropathy should be excluded.
• Syncope and sudden death are common in AL amyloidosis, but ventricular arrhythmias are uncommon. Electrical-mechanical dissociation is more common.
• Conduction disturbances are particularly common in some forms of infiltrative RCM, but not in amyloidosis.
• Depending on the etiology, patients may have a prior history of radiation therapy, heart transplantation, chemotherapy, or a systemic disease.

Physical

In respect to history and clinical profile, pericardial constriction and RCM may be indistinguishable. Remember that the 2 conditions can coexist in the same patient; for example, radiation therapy affects the myocardium as well as the pericardium. However, clinical features that help to differentiate the 2 conditions are described in Table 1 below.

• General examination
• • Patients may be more comfortable in the sitting position because of fluid in the abdomen and/or lungs. Weight loss and cardiac cachexia is not uncommon. Easy bruising, periorbital purpura, macroglossia, and other systemic findings, such as carpal tunnel syndrome, should advise the clinician to consider amyloidosis.
  • Increased jugular venous pressure is present, with rapid X and Y descents; the most prominent finding is usually the rapid Y descent. The degree of elevation of the jugular venous pressure indicates the severity of impaired filling of the right ventricle.
  • The jugular venous pulse fails to fall during inspiration and may actually rise (Kussmaul sign) in constrictive pericarditis. Although less common in RCM, Kussmaul sign cannot be used as an absolute means to distinguish RCM and constrictive pericarditis.
  • The pulse volume is decreased, consistent with decreased stroke volume and cardiac output.
  • Patients frequently have ascites and pitting edema of the lower extremities. The liver is usually enlarged and full of fluid, which may be painful. However, the liver may be enlarged and firm due to amyloid infiltration. Splenomegaly is rare.
• Cardiovascular system examination
• • Heart sounds S₁ and S₂ are normal, with a normal S₂ split.
  • A loud early diastolic filling sound (S₃) may be present but is uncommon in amyloidosis. A fourth heart sound is almost never present, possibly secondary to amyloid infiltration of the atria.
  • Murmurs due to mitral and tricuspid valve regurgitation may be heard, but they are secondary to the myocardial disease and usually not hemodynamically significant.
• Respiratory system examination
• • Breath sounds are decreased due to pleural effusion, frequently bilateral, and large in amyloidosis.
  • Crepitations or rales are rarely heard, even in advanced heart failure of amyloidosis.
• Table 1. Clinical Features of Constrictive Pericarditis and Restrictive Cardiomyopathy

  Clinical Features	Constrictive Pericarditis	Restrictive Cardiomyopathy
  History	Prior history of pericarditis or condition that causes pericardial disease	History of systemic disease (eg, amyloidosis, hemochromatosis)
  General examination	…	Peripheral stigmata of systemic disease
  Systemic examination - Heart sounds	Pericardial knock, high-frequency sound	Presence of loud diastolic filling sound S3, Low-frequency sound
  Murmurs	No murmurs	Murmurs of mitral and tricuspid insufficiency
  Prior chest x-ray	Pericardial calcification	Normal results of prior chest x-ray

Causes

Restrictive myocardial disease may be caused by various local and systemic disorders; many of them are rare and unlikely to be observed in the United States. However, primary amyloidosis is the most common cause of RCM in the United States. The etiology of RCM can be listed as follows:

• Idiopathic
• Specific heart muscle disease, such as primary amyloidosis
• • Endomyocardial fibrosis
  • Eosinophilic or Loeffler endomyocarditis
  • Infiltrative
  • • Amyloidosis - Common
    • Hemochromatosis (dilated left ventricle with restrictive physiology) - Rare
    • Glycogen storage disease - Rare
  • Treatment-induced
  • • Following heart transplantation
    • Following mediastinal radiation
  • Malignancy
  • • Metastatic endocardial and myocardial infiltration
    • Carcinoid heart disease
• Idiopathic/primary restrictive cardiomyopathy
• • A subset of patients have heart muscle disease of unknown cause that is manifested by heart failure and restrictive hemodynamics but without significant ventricular hypertrophy, endocardial thickening or fibrosis, associated eosinophilia, or other diagnostically distinct histopathological changes.
  • Males and females have been affected equally, but the prognosis appears to be worse in children than in adults. Children require relatively high filling pressures for maintenance of systolic output, and the therapeutic margin between volume depletion (leading to low output) and volume overload (leading to congestive heart failure) is narrow.
  • A familial pattern has been noted in some cases.
  • In addition to the presenting symptoms of right and left heart failure, as many as one third of patients with idiopathic RCM may present with thromboembolic complications. Pathologically, these patients have strikingly dilated atria, which may account for the increased cardiothoracic ratio observed on a chest radiograph. Echocardiography shows bilateral atrial enlargement with normal ventricular size but significant diffuse left ventricular hypertrophy, especially with amyloidosis. The histologic features include interstitial fibrosis, which is minimal in some and extensive in others.
• Amyloidosis
• • Amyloidosis is characterized by intercellular accumulation of amyloid material in amounts sufficient to impair the function of the involved organs. Depending on the amyloid protein composition, 4 different varieties of amyloidosis exist—(1) primary or myeloma-related amyloidosis, (2) secondary amyloidosis (ie, secondary to chronic diseases), (3) senile amyloidosis, and (4) familial amyloidosis.
  • The cardiac involvement in primary amyloidosis most commonly is associated with restrictive physiology. Amyloid infiltration of the heart is common in the elderly population (systemic senile amyloidosis) and may exhibit impaired diastolic filling properties but has other features that are more typical of a dilated cardiomyopathy.
  • The myeloma protein fibrils composed of immunoglobulin light chains are deposited diffusely throughout the myocardium and create a firm and rubbery consistency. Typically, the heart does not collapse when removed from the chest during autopsy.
  • On histologic examination, interstitial deposition of insoluble amyloid fibrils in all 4 cardiac chambers is observed. This can result in increased wall thickness without cavity dilatation.
• Involvement of the valves may create regurgitant lesions, but hemodynamically and clinically significant degree of regurgitation is unusual.
• • The granular sparkling (ie, scintillating) appearance on 2-dimensional echocardiography may be present and is typical, but not diagnostic, of cardiac amyloidosis. Echocardiography more typically shows biventricular thickening out of proportion to current or prior hypertension, biatrial enlargement, a restrictive filling pattern by Doppler echocardiography, and normal systolic function/EF until late in the disease.
  • In the early stages of the disease, typical restrictive hemodynamics may not be evident; however, in more advanced cases, typical restrictive hemodynamics are more likely. A corollary of these observations is that restrictive diastolic dynamics strongly predict cardiac death in patients with amyloidosis.
  • Cardiac biopsy is needed to confirm the diagnosis if doubt remains after noninvasive tests.
• Eosinophilic cardiomyopathy and endomyocardial fibrosis
• • Severe prolonged eosinophilia due to any cause (eg, allergic, autoimmune, parasitic, leukemic, idiopathic) can lead to eosinophilic infiltration of the myocardium. The intracytoplasmic granular content of activated eosinophils is believed to be responsible for the toxic damage to the heart. This eosinophilic cardiomyopathy, also known as Loeffler endocarditis, is associated with dense endomyocardial fibrosis, intraventricular thrombus formation, and obliteration of the ventricular cavity in its late stages; therefore, it is included in obliterative RCM.
  • Endomyocardial fibrosis, which is observed exclusively in equatorial Africa and less frequently in Asia and South America, was believed to be the end stage of eosinophilic endomyocarditis. However, endomyocardial fibrosis now is considered a separate entity because it does not exhibit eosinophilia. This condition demonstrates pathology that is similar to that described above (Loeffler endocarditis) and is grouped under obliterative RCM.
  • The prognosis is poor for patients with diffuse involvement of the heart in endomyocardial fibrosis, but localized lesions involving the valves are amenable to surgical repair or removal and replacement.
• Postirradiation fibrosis
• • Radiation-induced myocardial and endocardial fibrosis also can cause RCM. However, this complication of radiotherapy, like pericardial constriction, is evident several years after treatment.
  • The differential between constriction and restriction may be particularly difficult in these patients because the 2 conditions may coexist.

DIFFERENTIALS

Section 4 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Other Problems to be Considered

All causes of diastolic dysfunction are included in the differential diagnosis.

Constrictive pericarditis is the most important disease to consider, since it is potentially curable. The physical findings of constriction and restriction are similar and may be confusing to the less-experienced clinician.

Systemic hypertension, valvular aortic stenosis, and hypertrophic cardiomyopathy all cause impaired diastolic distensibility secondary to left ventricular hypertrophy (LVH). The thickened LV could be confused with amyloidosis on echocardiography, but the clinical findings are completely different.

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Lab Studies

• Laboratory studies are performed to establish the diagnosis, to quantitate the severity of the disease, and to monitor the patient.
• • Complete blood count with peripheral smear helps establish eosinophilia.
  • Blood gas analysis is performed to monitor hypoxia.
  • Obtain serum electrolytes, BUN and creatinine, and a liver function profile.
  • Serum iron concentrations, percent saturation of total iron-binding capacity, and serum ferritin levels are all increased in hemochromatosis.

Imaging Studies

• Chest radiograph: This typically shows cardiomegaly with bilateral pleural effusions.
• Two-dimensional echocardiography
• • This shows a nondilated, normally contracting, nonhypertrophied left ventricle and marked dilatation of both atria. However, amyloidosis typically shows diffuse increased LV thickening.
  • The ventricular cavity size may be normal or reduced. The wall thickness may be increased in patients with infiltrative diseases. Mural thrombus and cavity obliteration are features of obliterative cardiomyopathy. In contrast, dilated cardiomyopathy shows dilatation of all the chambers of the heart, and increased wall thickness, especially of the ventricular septum, is observed in hypertrophic cardiomyopathy.
  • Abnormal myocardial textures can also be appreciated using echocardiography. For example, granular speckling of the ventricular walls suggests the presence of infiltrative disease, such as amyloidosis.
  • Pericardial thickening is not reliably observed on echocardiography; MRI is suggested for exclusion of a thick pericardium.
• Doppler echocardiography
• • Doppler echocardiogram shows features of restriction to diastolic filling. Accentuated early diastolic filling of the ventricles (E), shortened deceleration time, and diminished atrial filling (A), which results in a high E-to-A ratio on the mitral inflow velocities, are present.
  • Variations of this diastolic (transmitral) blood flow with respiration help to differentiate between constrictive pericarditis and RCM.
  • Because both of the ventricles are encased in a common constricting pericardial sac, an inspiratory increase in inflow to the right ventricle causes a reciprocal reduction in the transmitral inflow to the left ventricle. Thus, a pattern of respiratory variation, with a diminished peak transmitral diastolic flow during inspiration, is characteristic of pericardial constriction but not of myocardial restriction.
  • In contrast, in RCM, the left-sided filling pressures are elevated further in inspiration.
• Tissue Doppler imaging: The use of pulsed-wave Doppler imaging is used in some centers as a noninvasive approach to distinguishing RCM and constrictive pericarditis. In addition to the information obtained by Doppler imaging, pulsed-wave Doppler imaging can define myocardial contraction and relaxation. This results in a measure referred to as the myocardial velocity gradient. Small studies have suggested that the myocardial velocity gradient is a specific measure that distinguishes these 2 entities well.
• Cardiac catheterization
• • Ventricular pressure tracings of increased right heart pressures, typical venous wave pattern, and the dip-plateau or square-root contour of the ventricular diastolic pressures (deep and rapid early decline in ventricular pressure at the onset of diastole, with a rapid rise to a plateau in early diastole) obtained by cardiac catheterization are the same in pericardial constriction and RCM. This dip and plateau or square-root sign of ventricular pressure is manifested in the atrial pressure tracing as a prominent descent followed by a rapid rise to a plateau.
  • A few criteria favor the pericardial disorder, as follows:
  • • Equalization of left and right ventricular filling pressures, with a difference of no more than 5 mm Hg between the 2 sides
    • Right ventricular end-diastolic pressure (RVEDP) equal to or exceeding one third of the level of the right ventricular systolic pressure (RVSP)
    • RVSP lower than 50 mm Hg
    • Persistence of diastolic equalization of pressures under stress or exercise or fluid challenge
  • In RCM, variance between right and left ventricular diastolic pressures is more likely to be greater than 5 mm Hg, RVEDP is more likely to be less than one third the RVSP, and the ventricular systolic pressure is more likely to be higher than 50 mm Hg.
• Radionuclide imaging: Radionuclide imaging shows increased diffuse uptake of technetium-99m (^99mTc) pyrophosphate and indium-111 (¹¹¹In) antimyosin in cardiac amyloidosis.
• Angiography: Angiography may show a small, thick-walled cavity in eosinophilic endomyocardial disease, which may be distorted significantly by a mural thrombus.
• Cardiovascular magnetic resonance (CMR): More recently, CMR has been used to assess abnormal myocardial interstitium. Preliminary reports suggest a characteristic pattern of global subendocardial late gadolinium enhancement coupled with abnormal myocardial and blood-pool gadolinium kinetics in RCM.
• Table 2. Investigation of Constrictive Cardiomyopathy and Restrictive Cardiomyopathy

  Investigation	Constrictive Cardiomyopathy	Restrictive Cardiomyopathy
  Chest radiograph	Pericardial calcification	Atrial dilatation causing increased cardiothoracic ratio, normal ventricular size
  CT scan/MRI	Pericardial thickening	No pericardial thickening
  Echocardiography	Normal-sized ventricles and atria; pericardial thickening, pericardial effusion may be observed	Nondilated, normally contracting, nonhypertrophied ventricles and marked dilatation of both atria; speckled texture of myocardium in cases of amyloid infiltration of the heart
  Doppler flow velocities on echocardiography	Respiratory changes (ie, decreased peak transmitral diastolic flow) during inspiration Equalization of the right- and left-sided filling pressures	No respiratory changes Greater elevation in the left-sided filling pressures
  Catheterization hemodynamics: 1) RVSP 2) RVEDP–to–RVSP ratio 3) RVEDP/LVEDP* equalization	1) £50 mm Hg 2) ³0.33 3) £5 mm Hg difference	1) ³50 mm Hg 2) £0.33 3) ³5 mm Hg difference
  Cardiac biopsy	Normal myocardium	Often diagnostic, showing abnormal myocardium

  *Left ventricular end-diastolic pressure

Other Tests

• Electrocardiography (ECG): The findings on ECG depend on the stage of the disease and the specific diagnosis. The ECG may be normal or just show some nonspecific ST-T wave changes, but rhythm disorders (notably atrial fibrillation) are common. Conduction abnormalities are uncommon in amyloidosis. Low QRS voltage is common in amyloidosis, out of proportion to the thick LV on echocardiography. A pseudo-infarct pattern is possible, secondary to myocardial infiltration and/or small vessel induced ischemia or infarction.

Procedures

• Cardiac biopsy: Ventricular biopsy obtained from either the right or the left ventricle has proved useful in certain cases in establishing whether endocardial or myocardial disease is present. Growing experience in this technique indicates a high diagnostic yield in diseases that may present with restriction hemodynamics, when noninvasive studies have failed to establish a clear-cut diagnosis. Amyloidosis demonstrates apple-green birefringence, stained with Congo red, viewed under a polarizing microscope.
• Liver biopsy is performed for diagnosis of hemochromatosis.
• Fine-needle aspiration of abdominal fat is easier and safer than myocardial biopsy to determine amyloidosis.
• Confirmation of the diagnosis of AL amyloidosis demands a search for a plasma cell dyscrasia.

TREATMENT

Section 6 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Medical Care

The goal of treatment in RCM is to reduce symptoms by lowering elevated filling pressures without significantly reducing the cardiac output. Presently, no drugs selectively enhance myocardial relaxation. Therefore, current therapy consists predominately of low-dose diuretics to lower the preload. Small initial doses should be administered to avoid hypotension because these patients are frequently extremely sensitive to alterations in left ventricular volume. Higher doses may be needed if the serum albumin level is low secondary to concomitant nephrotic syndrome.

• ACE inhibitors and angiotensin II inhibitors are poorly tolerated in patients with amyloidosis. Even small doses may result in profound hypotension, probably secondary to an autonomic neuropathy.
• Beta-blockers and calcium channel blockers are not documented to improve day-to-day symptoms or to favorably alter the natural history in patients with diastolic heart failure.
• No published data are available on the use of intravenous inotropic or vasodilator drugs.
• Patients with a history of embolization or atrial fibrillation should be anticoagulated. In patients with atrial fibrillation, the rate should be controlled adequately. Removal of the atrial contribution to ventricular filling may worsen the existing diastolic dysfunction, and a rapid ventricular response may further compromise diastolic filling, creating a crisis. Therefore, maintaining sinus rhythm is important, and medications such as amiodarone and beta-blocker are often used. Digoxin should be used with caution because it is potentially arrhythmogenic, particularly in patients with amyloidosis.
• Specific therapy
• • Antiplasma cell therapy with melphalan may slow the progress of systemic amyloidosis by stopping production of the paraprotein responsible for the formation of amyloid. The prognosis of patients with primary systemic amyloidosis remains poor, with a median survival of approximately 2 years despite intervention with alkylating-based chemotherapy in selected cases. In specific cases, chemotherapy has dramatic benefits, with improvement in systemic and cardiac manifestations.
  • Medical therapy with corticosteroids, cytotoxic agents (eg, hydroxyurea), and interferon is appropriate during the early phase of Loeffler endocarditis and improves symptoms and survival.
  • Chelation therapy or venesection is effective in patients with hemochromatosis to decrease the iron overload.
  • The treatment of Loeffler endocarditis consists of correctly identifying the condition before the end-stage fibrosis occurs; administration of corticosteroids, cytotoxic agents (eg, hydroxyurea), and interferon to suppress the intense eosinophilic infiltration of the myocardium; and conventional heart failure medication.

Surgical Care

• Patients with idiopathic RCM may have fibrosis of the sinoatrial and atrioventricular nodes that result in complete heart block, and, therefore, require permanent pacing. If cardioversion to treat atrial fibrillation is attempted, particularly in patients with amyloidosis, the abnormal sinus node may fail as an effective pacemaker. Patients with sinus node dysfunction and/or advanced conduction system disease also require treatment with implantation of a pacemaker.
• Cardiac transplantation can be considered in highly selected patients with refractory symptoms in idiopathic or familial RCM and amyloidosis. When noncardiac organ involvement is absent, a few patients with amyloidosis have undergone successful cardiac transplantation, combined with postoperative high-dose chemotherapy, to abolish recurrent amyloid production.
• Loeffler endocarditis: Surgical therapy, with excision of the fibrotic endocardium and replacement of the mitral and tricuspid calves, is palliative in the fibrotic stage of the disease but may provide symptomatic improvement. The operative mortality rate is in the range of 15-25%.
• Combined heart and liver transplantation in patients with heart and liver failure due to hemochromatosis has been successful in small numbers of patients. However, early morbidity and mortality is higher in dual organ transplantation than in single organ transplantation.
• Transplantation is a treatment option for cardiac sarcoidosis, but recurrence of sarcoid granulomas can occur in the transplanted heart.
• A surgical approach offers a cure for pericardial constriction but carries a potential for significant morbidity for RCM. Thus, establishing a clear diagnosis is crucial, and the advent of current sophisticated imaging technology helps in that regard. Fewer patients are now needing exploratory open-heart surgery to establish the correct diagnosis.
• Stem cell transplantation used in conjunction with high-dose chemotherapy is still considered experimental by most cardiologists. Its routine use has not yet been established.
• Finally, whether patients who have radiation-induced cardiac diseases are candidates for heart transplant is uncertain. Concerns have been raised as to whether their immune system would allow them to receive the immunosuppressive therapy necessary following the surgical procedure and whether relapse of their malignancy might occur.

MEDICATION

Section 7 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

The goals of pharmacotherapy are to reduce morbidity and to prevent complications.

Drug Category: Diuretics

Symptomatic treatment may improve symptoms of venous congestion through elimination of retained fluid and preload reduction.

Drug Category: Nitrates

Used to reduce preload in diastolic dysfunction.

Drug Category: Cardiac glycosides

Used to treat atrial fibrillation and systolic dysfunction in RCM.

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Prognosis

• The disease course varies depending on the pathology, and treatment often is unsatisfactory.

MISCELLANEOUS

Section 9 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

Medical/Legal Pitfalls

• All causes of diastolic dysfunction are included in the differential diagnosis of RCM. Establishing the diagnosis of RCM, and excluding constrictive pericarditis, is imperative.
• The etiology of RCM has been confused with constrictive pericarditis because patients can present with findings typical of constrictive pericarditis but they may actually have RCM. In the past, diagnosis of RCM was often made during surgery. Now, with wider knowledge of clinical findings and better imaging techniques, correct diagnosis can be strongly suggested and exploratory surgery can be avoided. The final diagnosis is most commonly made on biopsy of fat tissue, such as abdominal wall fat.

ACKNOWLEDGMENTS

Section 10 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

The authors and editors of eMedicine gratefully acknowledge the contributions of previous author Sarath Reddy, MD to the development and writing of this article.

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• References

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• Klein AL, Hatle LK, Burstow DJ, et al. Doppler characterization of left ventricular diastolic function in cardiac amyloidosis. J Am Coll Cardiol. Apr 1989;13(5):1017-26. [Medline].
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• Miller S, Riessen R. [MR imaging in cardiomyopathies]. Rofo. Nov 2005;177(11):1497-505.
• Rochitte CE, Tassi EM, Shiozaki AA. The emerging role of MRI in the diagnosis and management of cardiomyopathies. Curr Cardiol Rep. Feb 2006;8(1):44-52.
• Shammas RL, Movahed A. Sarcoidosis of the heart. Clin Cardiol. Jun 1993;16(6):462-72. [Medline].
• Sharma OP, Maheshwari A, Thaker K. Myocardial sarcoidosis. Chest. Jan 1993;103(1):253-8. [Medline].
• Valantine HA, Appleton CP, Hatle LK, et al. A hemodynamic and Doppler echocardiographic study of ventricular function in long-term cardiac allograft recipients. Etiology and prognosis of restrictive-constrictive physiology. Circulation. Jan 1989;79(1):66-75. [Medline].

Article Last Updated: Oct 3, 2006