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 is the least common of the 3 clinically recognized and described cardiomyopathies. Its principal abnormality is diastolic dysfunction, specifically restricted ventricular filling. Differentiation from constrictive pericarditis, a clinically similar entity, is difficult but important because the treatment options and prognosis differ drastically.

Pathophysiology

Restrictive cardiomyopathy can be idiopathic or secondary to a heart muscle disease that manifests as restrictive physiology. The common hemodynamic disturbance is impairment of ventricular filling due to the thickening and increased rigidity of the endocardium and myocardium secondary to infiltration by amyloid tissue or by fibrosis. Ventricular diastolic pressures are elevated and may inscribe a "dip and plateau" or "square root" pattern, both similar to constrictive pericarditis. Systolic function remains normal or near normal until late stages.

Frequency

United States

Occurrence of restrictive cardiomyopathy is rare with no quantifiable incidence.

International

Endomyocardial fibrosis (EMF), an etiologic factor of idiopathic restrictive cardiomyopathy, is a progressive disease of unknown cause that occurs most commonly in children and young adults in tropical and subtropical Africa, primarily in Uganda and Nigeria. EMF may account for up to one fourth of deaths due to cardiac disease in those areas.

Mortality/Morbidity

The natural history of restrictive cardiomyopathy is especially poor in children with heart failure. Adults experience a prolonged course of heart failure and may have complications of cardiac cirrhosis and thromboembolism. Patients who are refractory to supportive therapy usually die of low-output cardiac failure unless cardiac transplantation is an option.

Race

Natives of Africa, South America, and India are predisposed to EMF.

Age

EMF is most common in children and young adults.

CLINICAL

Section 3 of 11  

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

History

• Patients often present at an advanced stage of disease with pronounced cardiopulmonary symptoms. The patient's history may reveal the following:
• • Angina (uncommonly)
  • Dyspnea, orthopnea, or dyspnea on exertion
  • Paroxysmal nocturnal dyspnea
  • Peripheral edema
  • Abdominal discomfort, liver tenderness
  • Increased abdominal girth, ascites

Physical

• In addition to the findings listed below, a careful general physical examination must be conducted to search for extracardiac manifestations of a systemic disorder that may cause secondary restrictive cardiomyopathy (eg, hemochromatosis, amyloidosis, sarcoidosis, scleroderma).
• • Elevated jugular venous pulse, Kussmaul sign
  • y descent blunted relative to x
  • S3 and/or S4
  • Occasional mitral or tricuspid regurgitation murmur
  • Distant heart sounds
  • Pulmonary rales
  • Peripheral edema
  • Pulsus paradoxus - As the restrictive process progresses, no change in blood pressure occurs with inspiration.

Causes

• According to guidelines of the World Health Organization, cardiomyopathy refers to the disease of the myocardium secondary to an idiopathic cause (ie, primary cardiomyopathies). However, secondary infiltrative myocardial diseases, which are actually cardiac manifestations of systemic diseases, often are grouped together with cardiomyopathies.
• Idiopathic restrictive cardiomyopathy
• • EMF
  • Loeffler eosinophilic endomyocardial disease
• Secondary restrictive cardiomyopathy
• • Hemochromatosis
  • Amyloidosis
  • Sarcoidosis
  • Progressive systemic sclerosis (scleroderma)
  • Carcinoid heart disease
  • Glycogen storage disease of the heart
  • Radiation
  • Metastatic malignancy
  • Anthracycline toxicity

DIFFERENTIALS

Section 4 of 11  

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

WORKUP

Section 5 of 11  

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

Lab Studies

• CBC: An elevated eosinophil count may indicate eosinophilic endomyocardial disease.

Imaging Studies

• Chest radiography
• • Absence of cardiomegaly, normal cardiac silhouette, no pericardial calcification (seen in constrictive pericarditis)
  • Manifestations of pulmonary venous hypertension and pulmonary congestion
• Echocardiography
• • Normal to symmetrically thickened walls
  • Rapid early-diastolic filling, slow late-diastolic filling
  • Normal or slightly reduced ventricular volume and systolic function
  • Minimal to no respiratory variation in Doppler flow velocities
  • No pericardial thickening

• CT and MR imaging may help in differentiating from constrictive pericarditis.

Other Tests

• Endomyocardial biopsy
• • May detect typical eosinophil infiltration in the inflammatory stage
  • May detect myocardial fibrosis in later-stage cases
  • Negative findings do not exclude diagnosis
  • Risk of embolism may be due to dislodgement of recent ventricular thrombus
• Electrocardiography
• • Intraventricular conduction delays, left bundle-branch block (LBBB) common, and right bundle-branch block (RBBB) are most typical of amyloidosis and sarcoidosis.
  • Low voltage (usually secondary to amyloidosis and hemochromotosis)
  • Nonspecific ST-T changes
  • Various arrhythmias
  • Chamber enlargement

Procedures

• Cardiac catheterization
• • Elevated and equalized ventricular diastolic filling pressures
  • Dip and plateau or square root configuration of the diastolic portion of the ventricular pressure pulse
  • Normal to slightly decreased ejection fraction
  • Prominent a wave and x and y descent
  • Pulmonary artery pressure often greater than 40 mm Hg
  • Little to no variation in systolic pressure between the right and left ventricle with inspiration

TREATMENT

Section 6 of 11  

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

Emergency Department Care

With the possible exception of chelation therapy for hemochromatosis and corticoidsteroid therapy for sarcoidosis, restrictive cardiomyopathy has no specific treatment. ED care is symptom directed. The mainstay of treatment options include diuretics, vasodilators, angiotensin-converting enzyme inhibitors as indicated, as well as anticoagulation (if not contraindicated).

Consultations

Cardiology consultation is suggested in order to optimize management and establish a definitive diagnosis.

MEDICATION

Section 7 of 11  

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

As mentioned above, treatment of restrictive cardiomyopathy is symptomatic. Treatment goals include decreasing systemic and pulmonary congestion, lowering ventricular filling pressure, augmenting systolic pump function, and reducing risk for embolism.

Drug Category: Loop diuretics

Diuretics are used to reduce pulmonary and systemic congestion. Initiate therapy with a low dosage because relatively high levels of ventricular filling pressure must be maintained for adequate diastolic filling.

Drug Category: Inotropic agents

Digitalis and other positive inotropic agents generally are not indicated unless systolic pump function and contractility are impaired. Digitalis must be used with caution in patients with amyloid cardiomyopathy as they may be digoxin sensitive (arrhythmogenic) because of amyloid fibril binding of digoxin.

Drug Category: Vasodilators

These agents are used to reduce ventricular filling pressure. Avoid excessive decrease in preload and diastolic filling.

Drug Category: Anticoagulants

These agents are used to prevent embolism from ventricular thrombus.

FOLLOW-UP

Section 8 of 11  

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

Complications

• Thromboembolism
• Dysrhythmias
• Cardiac cirrhosis
• Progressive deterioration of cardiac function

Prognosis

• Prognosis generally is poor in the adult population, with progressive deterioration.
• The outlook is especially bad in children with heart failure.
• Surgical treatment (cardiac transplantation) is potentially helpful. It is contraindicated in amyloidosis.

MISCELLANEOUS

Section 9 of 11  

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

Medical/Legal Pitfalls

• Differentiation from constrictive pericarditis is difficult but important. While restrictive cardiomyopathy has no specific therapy, constrictive pericarditis is potentially curable with surgery.

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, Andrew Wackett, 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

• Braunwald E, Abelmann WH. Atlas of Heart Diseases. Vol 2. 1994:53-61.
• Davies MJ, Mann JM. Systemic pathology. In: The Cardiovascular System. Vol 10. 1995:1409-16.
• Goldstein JA. Differentiation of constrictive pericarditis and restrictive cardiomyopathy. ACC Ed Highlights. 1998;Fall:14-22.
• Higano ST, Azrak E, Tahirkheli NK, Kern MJ. Hemodynamic rounds series II: hemodynamics of constrictive physiology: influence of respiratory dynamics on ventricular pressures. Catheter Cardiovasc Interv. Apr 1999;46(4):473-86. [Medline].
• Kasper DL, Braunwald E, Fauci AS, eds. Harrison's Principles of Internal Medicine. McGraw-Hill; 2005:chap 221.
• Kushwaha SS, Fallon JT, Fuster V. Restrictive cardiomyopathy. N Engl J Med. Jan 23 1997;336(4):267-76. [Medline].
• Schlant RC, Alexander RW, eds. The Heart. McGraw-Hill; 1994:1637-45.
• Tintinalli JE, Kelen GD, Stapczynski JS, eds. Emergency Medicine: A Comprehensive Study Guide. McGraw-Hill;2004:381.
• Wald DS, Gray HH. Restrictive cardiomyopathy in systemic amyloidosis. QJM. May 2003;96(5):380-2. [Medline].
• Willerson JT, Cohn JN, ed. Cardiovascular Medicine. Churchill Livingstone; 1995:871-86.

Article Last Updated: Jul 3, 2008