eMedicine Specialties > Cardiology > Myocardial Disease and Cardiomyopathies
Cardiomyopathy, Restrictive: Differential Diagnoses & Workup
Updated: Oct 9, 2008
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
Differential Diagnoses
Aortic Stenosis
Cardiac Tamponade
Cardiomyopathy, Hypertrophic
Hypertensive Heart Disease
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
Laboratory Studies
Laboratory studies are performed to establish the diagnosis of restrictive cardiomyopathy, 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.
- Serum brain natriuretic peptide (BNP) level: Recent data suggest that serum BNP levels are nearly normal in patients with constrictive physiology of heart failure and grossly elevated in patients with restrictive physiology, despite nearly identical clinical and hemodynamic presentation.1
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 restrictive cardiomyopathy (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 (99m Tc) pyrophosphate and indium-111 (111 In) 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
Open table in new window
Table
| 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) ³ 0.33 3) £ 5 mm Hg difference | 1) ³ 50 mm Hg 2) £ 0.33 3) ³ 5 mm Hg difference |
| Cardiac biopsy | Normal myocardium | Often diagnostic, showing abnormal myocardium |
| 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) ³ 0.33 3) £ 5 mm Hg difference | 1) ³ 50 mm Hg 2) £ 0.33 3) ³ 5 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.
More on Cardiomyopathy, Restrictive |
| Overview: Cardiomyopathy, Restrictive |
 Differential Diagnoses & Workup: Cardiomyopathy, Restrictive |
| Treatment & Medication: Cardiomyopathy, Restrictive |
| Follow-up: Cardiomyopathy, Restrictive |
| References |
| « Previous Page | Next Page » |
References
Leya FS, Arab D, Joyal D, Shioura KM, Lewis BE, Steen LH, et al. The efficacy of brain natriuretic peptide levels in differentiating constrictive pericarditis from restrictive cardiomyopathy. J Am Coll Cardiol. Jun 7 2005;45(11):1900-2. [Medline].
Applefeld MM, Wiernik PH. Cardiac disease after radiation therapy for Hodgkin's disease: analysis of 48 patients. Am J Cardiol. Jun 1983;51(10):1679-81. [Medline].
Bonow RO, Udelson JE. Left ventricular diastolic dysfunction as a cause of congestive heart failure. Mechanisms and management. Ann Intern Med. Sep 15 1992;117(6):502-10. [Medline].
Brosius FC 3rd, Waller BF, Roberts WC. Radiation heart disease. Analysis of 16 young (aged 15 to 33 years) necropsy patients who received over 3,500 rads to the heart. Am J Med. Mar 1981;70(3):519-30. [Medline].
Burstow DJ, Tajik AJ, Bailey KR, et al. Two-dimensional echocardiographic findings in systemic sarcoidosis. Am J Cardiol. Feb 15 1989;63(7):478-82. [Medline].
Falk RH, Comenzo RL, Skinner M. The systemic amyloidoses. N Engl J Med. Sep 25 1997;337(13):898-909. [Medline].
Katritsis D, Wilmshurst PT, Wendon JA, et al. Primary restrictive cardiomyopathy: clinical and pathologic characteristics. J Am Coll Cardiol. Nov 1 1991;18(5):1230-5. [Medline].
Klein AL, Cohen GI, Pietrolungo JF, et al. Differentiation of constrictive pericarditis from restrictive cardiomyopathy by Doppler transesophageal echocardiographic measurements of respiratory variations in pulmonary venous flow. J Am Coll Cardiol. Dec 1993;22(7):1935-43. [Medline].
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].
Kushwaha SS, Fallon JT, Fuster V. Restrictive cardiomyopathy. N Engl J Med. Jan 23 1997;336(4):267-76. [Medline].
Lewis AB. Clinical profile and outcome of restrictive cardiomyopathy in children. Am Heart J. Jun 1992;123(6):1589-93. [Medline].
Miller S, Riessen R. [MR imaging in cardiomyopathies]. Rofo. Nov 2005;177(11):1497-505. [Medline].
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. [Medline].
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].
Further Reading
Keywords
restrictive cardiomyopathy, RCM, myocardium, Loeffler's endocarditis, chronic endomyocardial fibrosis, diastolic heart failure, primary amyloidosis, eosinophilic, hemochromatosis, glycogen storage disease
