restrictive cardiomyopathy
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Introduction
Restrictive cardiomyopathy results from pathologic infiltration of the myocardium through a variety of etiologies.
Etiology
- amyloidosis (most common identifiable cause)
- sarcoidosis
- glycogen storage disease
- hemochromatosis
- most often presents as dilated cardiomyopathy
- may present as restrictive cardiomyopathy
- endomyocardial fibrosis (mainly in west & central Africa)
- hypereosinophilic syndromes
- scleroderma
- anthracycline toxicity
- doxorubicin, daunorubicin idarubicin, epirubicin,
- mitoxantrone (an anthraquinone)
- may cause dilated cardiomyopathy or restrictive cardiomyopathy
- effect increase with radiation therapy
- radiation therapy
- may occur years or decades after exposure
- familial forms
- idiopathic
Pathology
- myocardial infiltration
- non-caseating granulomas, inflammation & fibrosis with sarcoidosis
- iron deposits associated with myocardial or endocardial fibrosis with hemochromatosis
- patchy myocardial fibrosis with scleroderma
- diffuse interstitial fibrosis with radiation
- abnormal diastolic ventricular filling
- elevated ventricular filling pressures
- pulmonary hypertension is often present
- systolic dysfunction, variable
- cardiac aneurysm may occur
- other organs involved in underlying disease process[3]
Genetics
- associated with defects in troponin-I, TNNI3 (type 1)
- associated with defects in troponin-T, TNNT2 (type 3)
- associated with defects in alpha-actin, ACTC1 [3]
- associated with defects in myosin heavy chain beta, MYH7[3]
- associated with mutation in transthyretin gene, TTR (amyloidosis)
Clinical manifestations
- atrial fibrillation
- right heart failure more severe than left heart failure[3]
- symptoms of high filling pressures[3]
- increased jugular venous pressure with inspiration, Kussmaul's sign
- peripheral edema (> 1+), pleural effusion, hepatic congestion
- dyspnea
- fatigue
- exercise intolerance
- pericardial knock
- S4 heart sound may be present[3]
- conflicting statements regarding muffled heart sounds*
- cardiac conduction system disorders (sarcoid)
- diminished apical impulse
- pulsus paradoxus absent[3]
- murmur of mitral regurgitation may be present[3]
- hepatomegaly & ascites may be late manifestations[3]
* NEJM knowledge+ claims no muffled heart sounds
Laboratory
- elevated serum B-type natriuretic peptide (serum BNP)
- mean value > 800 pg/mL[3] (130 pg/mL in constrictive pericarditis)
- sensitive, but not specific for differentiating restrictive cardiomyopathy from constrictive pericarditis
Diagnostic procedures
- electrocardiogram (EKG)
- low voltage
- conduction abnormality, bundle-branch block
- no specific findings[3]
- echocardiogram
- myocardial thickening vs normal wall thickness
- left ventricular hypertrophy, diastolic dysfunction, restrictive diastolic filling
- normal ventricular size, preserved systolic function
- biatrial enlargement
- early mitral flow velocity increased
- mitral regurgitation may be present
- pericardial thickening suggests pericarditis[3]
- cardiac catheterization
- prominent x-descent & y-descent
- elevated atrial pressures
- elevated left & right ventricular filling pressures with greater elevation in left ventricular filling pressure
- distinguish restrictive pericarditis (equalization of left & right filling pressures)
- early dip & plateau pattern in right & left ventricle diastolic pressure tracing
- concordance of LV & RV pressures during respiration[3]
- systolic function may be normal[3]
- pulmonary hypertension may be present
- right ventricular endomyocardial biopsy to distinguish amyloidosis, hemochromatosis, sarcoidosis
- biopsy yield is low in sarcoidosis & other disorders with patchy myocardial involvement[3]
Radiology
- chest X-ray
- computed tomography (thorax)
- normal pericardium
- pericardial thickening or calcification suggests pericarditis[3]
- cardiac magnetic resonance imaging
- late gadolinium enhancement of papillary muscle[3]
- cardiac technetium-99m pyrophosphate scintigraphy diagnostic for transthyretin cardiac amyloidosis[3]
Complications
Differential diagnosis
- constrictive pericarditis
- distinction is critical since surgery is indicated for constrictive pericarditis
- presence of S4 favors restrictive cardiomyopathy[3]
- mitral regurgitation favors restrictive cardiomyopathy
- pulsus paradoxus favors constrictive pericarditis[3]
- echocardiogram or CT of thorax distinguishes
- serum BNP > 800 pg/mL favors restrictive cardiomyopathy
- pericardial effusion (muffled heart sounds)
- infiltrative diseases
- amyloidosis (increased wall thickness, low-voltage ECG)[3]
- sarcoidosis (bilateral hilar lymphadenopathy)
- storage diseases
- hemochromatosis (normal wall size)[3]
- Fabry's disease
- radiation injury (normal wall size)[3]
- eosinophilic syndromes (normal wall size)[3]
- HFpEF: left heart failure, 1+ peripheral edema, bibasilar crackles
Management
- general measures
- diuretics for pulmonary & systemic congestion
- digoxin
- left ventricular systolic dysfunction
- patients with cardiac amyloidosis have increased susceptibility to digoxin toxicity
- vasodilator therapy
- elevated end-diastolic filling pressures may be necessary to maintain cardiac output; avoid excessive reduction in preload
- beta-blockers & calcium channel blockers[3]
- avoid if elevated heart rate needed to maintain cardiac output
- beta-blockers, diltiazem or verapamil may enhance diastolic function
- specific therapy aimed at underlying cause
- cardiac hemochromatosis
- sarcoidosis
- glucocorticoids
- increased survival with steroids not established
- amyloidosis
- no known effective therapy
- stem cell transplantation for mutant transthyretin may result in regression of cardiomyopathy[3]
- avoid digoxin & calcium channel blockers
- binding of amyloid, increased toxicity
- heart transplant, liver transplant
- endomyocardial fibrosis
- hypereosinophilia
- atrial fibrillation
- cardiac tranplantation recommended over pulmonary vein isolation[3]
More general terms
More specific terms
Additional terms
- constrictive pericarditis
- left ventricular diastolic dysfunction; heart failure with preserved ejection fraction (HFpEF)
References
- ↑ Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 134
- ↑ Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 108-110
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 3.25 3.26 3.27 Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 15 16, 17, 18, 19. American College of Physicians, Philadelphia 1998, 2006, 2009, 2012, 2015, 2018, 2022.
Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022 - ↑ Seward JB, Casaclang-Verzosa G. Infiltrative cardiovascular diseases: cardiomyopathies that look alike. J Am Coll Cardiol. 2010 Apr 27;55(17):1769-79. PMID: https://www.ncbi.nlm.nih.gov/pubmed/20413025
- ↑ Nihoyannopoulos P, Dawson D. Restrictive cardiomyopathies. Eur J Echocardiogr. 2009 Dec;10(8):iii23-33 PMID: https://www.ncbi.nlm.nih.gov/pubmed/19889655
- ↑ Ammash NM, Seward JB, Bailey KR, Edwards WD, Tajik AJ. Clinical profile and outcome of idiopathic restrictive cardiomyopathy. Circulation. 2000 May 30;101(21):2490-6. PMID: https://www.ncbi.nlm.nih.gov/pubmed/10831523
- ↑ Sorajja P Invasive hemodynamics of constrictive pericarditis, restrictive cardiomyopathy, and cardiac tamponade. Cardiol Clin. 2011 May;29(2):191-9 PMID: https://www.ncbi.nlm.nih.gov/pubmed/21459242
- ↑ Garcia MJ. Constrictive Pericarditis Versus Restrictive Cardiomyopathy? J Am Coll Cardiol. 2016 May 3;67(17):2061-76. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/27126534 Free Article