para>Primary
Genetic
Hypertrophic cardiomyopathy (HCM)
Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D)
Left ventricular (LV) noncompaction (LVNC)
Glycogen storage (Danon type, PRKAG2)
Conduction defects
Mitochondrial myopathies
Ion channel disorders: long QT syndrome, Brugada, short QT syndrome, catecholaminergic ventricular tachycardia (CVPT), Asian SUNDS
Mixed
Dilated cardiomyopathy (DCM) (genetic or nongenetic)
Restrictive
Acquired
Myocarditis, stress cardiomyopathy, peripartum, tachycardia-induced, infants of type 1 diabetic mothers
Secondary (see list below)
Specific
Ischemic
Valvular
Hypertensive
Congenital heart disease
Patients with end-stage cardiomyopathy have stage D heart failure or severe symptoms at rest refractory to standard medical therapy.System(s) affected: cardiovascular; renal
Pediatric Considerations
Etiology: idiopathic, viral, congenital heart disease, and familial �
Pregnancy Considerations
May occur in women postpartum �
Epidemiology
Predominant age: Ischemic cardiomyopathy is the most common etiology; predominantly in patients aged >50 years. Consider uncommon causes in young. �
Incidence
- 60,000 patients <65 years die each year from end-stage heart disease.
- 35,000-70,000 people might benefit from cardiac transplant or chronic support.
Prevalence
Most rapidly growing form of heart disease �
Etiology and Pathophysiology
The most frequent causes are in bold: �
- Ischemic heart disease: most common etiology; up to 66% of patients
- Hypertension
- Valvular heart disease
- Primary genetic causes
- Congenital heart disease
- Peripartum/postpartum
- Endocrine
Diabetes mellitus
Hyperthyroidism
Hypothyroidism
Hyperparathyroidism
Pheochromocytoma
Acromegaly
- Nutritional deficiencies
Beriberi, pellagra, scurvy, selenium, carnitine, kwashiorkor
- Autoimmune/collagen
- Infectious causes
Viral (e.g., HIV, coxsackievirus, adenovirus)
Bacterial and mycobacterial (e.g., diphtheria, rheumatic fever)
Parasitic (e.g., toxoplasmosis, Trypanosoma cruzi)
- Infiltrative (2)
Amyloidosis
Gaucher disease
Hurler disease
Hunter disease
Fabry disease
- Storage
- Neuromuscular/neurologic
- Toxic
Alcohol
Drugs and chemotherapy: anthracyclines, cyclophosphamide, Herceptin
Radiation
Heavy metal, chemical agents
- Inflammatory (granulomatous):
- Idiopathic
- Endomyocardial
Genetics
Autosomal dominant HCM is the most common form of primary genetic cardiomyopathy (1/500 in the general population). Genetic causes of DCM are less common, accounting for 1/3 cases, with mostly autosomal dominant inheritance. LNC and ARVC are also inherited in an autosomal dominant fashion in addition to LQTS and other ion-channel disorders. �
Risk Factors
- Hypertension
- Hyperlipidemia
- Obesity
- Coronary artery diease
- Diabetes mellitus
- Smoking
- Physical inactivity
- Excessive alcohol intake
- Dietary sodium
- Obstructive sleep apnea
- Chemotherapy
General Prevention
Reduce salt and water intake; home BP and daily weight measurement �
Diagnosis
History
- Dyspnea at rest or with exertion
- Paroxysmal nocturnal dyspnea
- Orthopnea
- Postprandial dyspnea
- Right upper quadrant pain or bloating
- Midabdominal pain
- Fatigue
- Syncope
- Edema
Physical Exam
- Tachypnea
- Cheyne-Stokes breathing
- Low pulse pressure
- Cool extremities
- Jugular venous distention
- Bibasilar rales
- Tachycardia
- Displaced point of maximal impulse (PMI)
- S3 gallop
- Blowing systolic murmur
- Hepatosplenomegaly
- Ascites
- Edema
Differential Diagnosis
- Severe pulmonary disease
- Primary pulmonary hypertension
- Recurrent pulmonary embolism
- Constrictive pericarditis
- Some advanced forms of malignancy
- Anemia
Diagnostic Tests & Interpretation
- ECG: LV hypertrophy, interventricular conduction delay, atrial fibrillation, evidence of prior Q-wave infarction
- Hyponatremia
- Prerenal azotemia
- Anemia
- Mild elevation in troponin
- Elevated B-type natriuretic peptide (BNP) or pro-BNP
- Mild hyperbilirubinemia
- Elevated liver function tests
- Elevated uric acid
Initial Tests (lab, imaging)
- ECG
- Chest radiograph
- Echocardiography
In dilated cardiomyopathy, 4-chamber enlargement and global hypokinesis are present.
In hypertrophic cardiomyopathy, severe LV hypertrophy is present.
Segmental contraction abnormalities of the LV are indicative of previous localized myocardial infarction.
- Cardiac MRI
- Myocardial stress perfusion imaging (MPI)
Diagnostic Procedures/Other
Cardiac catheterization �
- Helpful to rule out ischemic heart disease
- Characterize hemodynamic severity
- Pulmonary artery catheters may be reasonable in patients with refractory heart failure to help guide management.
Treatment
See "Heart Failure, Chronic"� for detailed treatment protocols. �
General Measures
- Reduction of filling pressures
- Treatment of electrolyte disturbances
Medication
First Line
- Systolic failure syndromes
ACE inhibitors: All considered equally effective; initiate at low doses and titrate as tolerated to target doses (3)[A].
Loop diuretics
Furosemide, 40-120 mg/day or TID (3)[A]
β-Blockers
Metoprolol succinate, 12.5-200 mg/day; carvedilol, 3.125-25 mg BID; or bisoprolol, 1.25-10 mg/day (3)[A]
Patients with New York Heart Association (NYHA) II-IV heart failure, ejection fraction (EF) <35%, on standard therapy: aldosterone antagonists: spironolactone or eplerenone (3)[A]
Digoxin, 0.125-0.25 mg/day for symptomatic patients on standard therapy (3)[B]
Combination hydralazine/isosorbide dinitrate is 1st-line treatment in African American patients with class III-IV symptoms already on standard therapy and for all patients with reduced EF and symptoms incompletely responsive to ACE inhibitor and β-blocker (3)[A].
β-Blockers: low cardiac output, 2nd- or 3rd-degree heart block
Avoid use of diltiazem and verapamil in patients with systolic dysfunction.
Aldosterone antagonists: oliguria, anuria, renal dysfunction
Loop diuretics: hypokalemia, hypomagnesemia
ACE inhibitors: pregnancy, angioedema
- Precautions
In patients with chronic kidney disease, digoxin dosage should be ≤0.125 mg/day and drug levels followed carefully to avoid toxicity.
Closely monitor electrolytes.
ACE inhibitors: Initiate with care if BP is low. Begin with low-dose captopril, such as 6.25 mg TID.
β-Blockers: Avoid in patients with evidence of poor tissue perfusion; they may further depress systolic function.
Milrinone, dobutamine: long-term use associated with increased mortality
- Medications TO AVOID
NSAIDs
Glitazones
Cilostazol
Second Line
- Angiotensin receptor blockers as an alternative to ACE inhibitors
- Inotropic therapy (e.g., dobutamine or milrinone) for cardiogenic shock and support prior to surgery or cardiac transplantation (3)[B]
- Continuous inotrope infusion may be considered in stage D outpatients for symptom control in those who are not eligible for transplantation or mechanical circulatory support (3)[B].
Issues for Referral
Management by a heart failure team improves outcomes and facilitates early transplant referral. �
Additional Therapies
- Prophylactic implantable cardioverter defibrillator (ICD) should be considered for patients with a left ventricular ejection fraction (LVEF) <35% and mild to moderate symptoms (3)[A].
- Cardiac resynchronization therapy (CRT) is recommended and should be considered for patients in sinus rhythm with a QRS >150 msec, LVEF <35%, in FC I-III and ambulatory FC IV patients (3)[A].
- Patients with severe, refractory heart failure with no reasonable expectation of improvement should not be considered for an ICD.
- Consideration of an LV assist device as "permanent"� or destination therapy or cardiac transplantation is reasonable in selected stage D patients.
Ongoing Care
Diet
Low-fat, low-salt, fluid restriction �
Prognosis
~20-40% of patients in NYHA functional class IV die within 1 year. With a transplant, 1-year survival is as high as 94%. �
Complications
Worsening congestive heart failure syncope, renal failure, arrhythmias, or sudden death �
References
1.Maron �BJ, Towbin �JA, Thiene �G, et al. Contemporary definitions and classification of the cardiomyopathies: an American Heart Association Scientific Statement from the Council on Clinical Cardiology, Heart Failure and Transplantation Committee; Quality of Care and Outcomes Research and Functional Genomics and Translational Biology Interdisciplinary Working Groups; and Council on Epidemiology and Prevention. Circulation. 2006;113(14):1807-1816. �[View Abstract]2.Seward �JB, Casaclang-Verzosa �G. Infiltrative cardiovascular diseases: cardiomyopathies that look alike. J Am Coll Cardiol. 2010;55(27):1769-1779. �[View Abstract]3.Yancy �CW, Jessup �M, Bozkurt �B, et al. 2013 ACCF/AHA guideline for the management of heart failure: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2013;128:1-375.
Additional Reading
See Also
Alcohol Abuse and Dependence; Alcohol Withdrawal; Amyloidosis; Congestive Heart Failure; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Hypertension, Essential; Hypothyroidism, Adult; Idiopathic Hypertrophic Subaortic Stenosis; Protein Energy Malnutrition; Rheumatic Fever; Sarcoidosis �
Codes
ICD10
- I42.9 Cardiomyopathy, unspecified
- I42.2 Other hypertrophic cardiomyopathy
- I42.1 Obstructive hypertrophic cardiomyopathy
- I43 Cardiomyopathy in diseases classified elsewhere
- I42.4 Endocardial fibroelastosis
- I42.5 Other restrictive cardiomyopathy
- I42.8 Other cardiomyopathies
- I42.6 Alcoholic cardiomyopathy
- I42.3 Endomyocardial (eosinophilic) disease
- I42.7 Cardiomyopathy due to drug and external agent
- I42.0 Dilated cardiomyopathy
ICD09
- 425.4 Other primary cardiomyopathies
- 425.18 Other hypertrophic cardiomyopathy
- 425.11 Hypertrophic obstructive cardiomyopathy
- 425.8 Cardiomyopathy in other diseases classified elsewhere
- 425.5 Alcoholic cardiomyopathy
- 425.7 Nutritional and metabolic cardiomyopathy
- 425.9 Secondary cardiomyopathy, unspecified
SNOMED
- 85898001 Cardiomyopathy (disorder)
- 233873004 Hypertrophic cardiomyopathy (disorder)
- 45227007 Hypertrophic obstructive cardiomyopathy (disorder)
- 195029002 Cardiomyopathy associated with another disorder (disorder)
- 83521008 Dilated cardiomyopathy secondary to alcohol (disorder)
- 399020009 Congestive cardiomyopathy (disorder)
- 415295002 Restrictive cardiomyopathy (disorder)
- 195023001 Nutritional and metabolic cardiomyopathies (disorder)
- 89461002 Primary cardiomyopathy
Clinical Pearls
- Cardiomyopathy represents the end-stage of a large number of disease processes involving the heart muscle.
- Ischemic, hypertensive, postviral, familial, alcoholic, and incessant tachycardia-induced are the most common cardiomyopathy varieties seen in the United States.
- Core therapy for heart failure applies: salt restriction, diuretics, ACE inhibitors, β-blockers, digoxin, and electrical treatments, such as cardiac resynchronization and implantable defibrillators, as appropriate.