Cardiomyopathy Flashcards
What is cardiomyopathy?
“heart muscle disease”
What are the 2 most common forms of cardiomyopathy in the US?
Ischemic cardiomyopathy and valvular cardiomyopathy
What are the WHO classifications for heart failure?
Functional Classification
- Dilated Cardiomyopathy
- Hypertrophic cardiomyopathy
- Restrictive Cardiomyopathy
- RV Dysplasia
- Unclassified (Obliterative)
What is dilated cardiomyopathy?
Dilated left/both ventricle(s) with impaired contraction
What are the common etiologies of dilated cardiomyopathy?
Ischemic, idiopathic, familial, viral, alcoholic, toxic, valvular
What is hypertrophic cardiomyopathy?
Left and/or right ventricular hypertrophy
What is the common etiology of hypertrophic cardiomyopathy?
Familial with autosomal dominant inheritance
What is restrictive cardiomyopathy?
Restrictive filling and reduced diastolic filling of one/both ventricles, Normal/near normal systolic function
What are the common etiologies of restrictive cardiomyopathy?
Idiopathic, amyloidosis, endomyocardial fibrosis
What is primary cardiomyopathy?
Solely or predominantly confined to heart muscle and are relatively few in number; Can be genetic, nongenetic or acquired
What is secondary cardiomyopathy?
Pathological myocardial involvement as part of a large number and variety of generalized systemic (multi-organ) disorders
What are symptoms of cardiomyopathy?
Reduced exercise tolerance, Shortness of breath, Congestion / Fluid Retention, Difficulty in sleeping (Orthopnea, PND), Weight loss (or gain due to fluid)
What are signs on physical exam of cardiomyopathy?
JVP/ HJ reflux, Rales / Pleural effusions, Gallops (S3 and S4), Hepatomegaly / Ascites, Edema, Cool Extremities, Pulses Alternans / Bifid Pulse
What can be diagnosed on endocardial biopsy?
Myocarditis (giant cell, lyme, toxoplasmosis, etc), Infiltrative (amyloidosis, hemochromatosis, etc), Toxins (radiation injury), Genetic (glycogen storage, infiltrative)
Which dilated cardiomyopathies can be reversed?
Ischemic with viable myocardium, Uncorrected Valvular Disease; some inflammatory, toxic (stop drinking alochol! etc), hypersensitivity, endocrine, metaoblic, nutritional, infiltrative
What are the goals of cardiomyopathy treatment?
- Identification and correction of underlying condition causing heart failure.
- Elimination of acute precipitating cause of symptoms.
- Modulation of neurohormonal response to prevent progression of disease.
- Improve long term survival.
How should cardiomyopathy be treated?
Stage A: ace-inhibitor; Stage B: ace-inhibitor, beta blocker; Stage C: diuretics, ACEI, beta-blockers, some need pacemakers; Stage D: heart transplant, permanent mechanical support
What is myocarditis?
An inflammatory infiltrate in the myocardium associated with myocyte damage
What are common causes of myocarditis?
Idiopathic (postviral/lymphocytic); Coxsackie B virus, echovirus, adenovirus commonly; Idiopathic giant cell myocarditis; Sarcoidosis; Drug induced; hypersensitivity and toxic; Seeding of myocardium by bacteria or fungus or parasite; Systemic disease-associated; collagen vascular diseases, rheumatic fever.
What is Giant Cell Myocarditis?
Fulminant onset myocarditis rapidly progressing to heart failure and/or arrhythmias; 20% of patients have another autoimmune disease
What is Hypersensitivity Myocarditis?
Typically a drug reaction; Patients may have rash, fever, peripheral eosinophilia; Tend to be interstitial with little myocyte damage; Inflammatory infiltrates are rich in eosinophils.
How does Chagas affect the heart?
In the chronic stage, it causes cardiomyopathy, which causes heart rhythm abnormalities and can result in sudden death.; 1/3 develop digestive system damage (megacolon and mega esophagus)
What is acute rheumatic fever?
Antibodies against Streptococcal M proteins cross react with similar antigenic determinants in heart, joints, skin, and brain
How can you identify rheumatic fever?
Myocardial involvement with an Aschoff body – a cardiac ‘granuloma’
How can chemotherapy affect the heart?
Irreversible cardiomyopathy (e.g. anthracycline derivatives for breast cancer, sarcomas, lymphomas; cyclophosphamide for lymphomas, leukemias; pacitaxel for breast cancer); in some cases - Reversible (monoclonal antibodies such as trastuzumab for Her2 (+) breast cancer; small molecule tyrosine kinase inhibitors)
What is Anthracycline Cardiotoxicity?
1.Acute, within days: EKG changes, LV dysfunction is usually transient and reversible.
2.Late-onset: ventricular dysfunction and arrhythmias; irradiation increases risk.
3.Dilated cardiomyopathy: cumulative, dose dependent, irreversible, progressive.
Overall incidence of severe CHF is 2-3%.
Causes cytoplasmic vacuoles
What is the epidemiology of HCM?
1 in 500 people (most common genetic cardiovascular disease)
–Incidence is about 0.2% to 0.5% of general population.
•An estimated 600,000 to 1.5 million Americans have HCM.
•HCM can present at anytime in any age of life
•Most people are not aware they have HCM because symptoms can go unnoticed and most people with the disease live healthy, normal lives
What is the pathophysiology of HCM?
Systole –dynamic outflow tract gradient; Diastole –impaired diastolic filling, increased filling pressure; Myocardial ischemia – increased muscle mass, filling pressure, O2 demand; decreased vasodilator reserve, capillary density; abnormal intramural coronary arteries; systolic compression of arteries; Mitral Regurgitation; Arrhythmias
What are symptoms of HCM?
- Chest pain
- Fainting, especially during exercise
- Light-headedness or dizziness, especially after activity or exercise
- Palpitations
- Shortness of breath
- Fatigue, reduced activity tolerance
- Shortness of breath
- Heart failure
What are the clinical manifestations of HCM?
Asymptomatic, echocardiographic finding; Symptomatic: dyspnea in 90%, angina pectoris in 75%, fatigue, pre-syncope, syncope, increased risk of SCD in children and adolescents; palpitation, PND, CHF, dizziness less frequent
What are the typical findings of HCM on physical exam?
- Apex localized, sustained
•Palpable S4
•Tripple ripple
•Prominent “a” wave
•Rapid upstroke carotid pulse, “jerky” bifid (spike-and-dome pulse)
•Harsh systolic ejection murmur across entire precordium to the apex & heart base
•MR: separate murmur: severity of MR related to degree of outflow obstruction
What are the genetics associated with HCM?
•First discovered in the 1950s
•Autosomal dominant trait
–Mutations in genes that encode one of the sarcomere proteins including
- More than 400 mutations in these genes.
–Frequency: 45% of mutations occur in beta myosin heavy chain gene, 35% involve cardiac myosin binding protein C gene.
Males and females equally affected
Onset of clinical symptoms is delayed until adolescence or early adulthood
Certain mutations (and certain clinical features) are highly predictive of sudden death
How can you tell the difference between an athletic heart and an HCM heart?
HCM can be asymmetric, Athlete is concentric and regresses; HCM wall thickness 15+ mm, Athlete less than 15; LA in HCM 40+; LVEDD in HCM less than 45; diastolic function in HCM is always abnormal vs normal in athletic heart
What is the natural history and prognosis of HCM?
Annual mortality 3% in referral centers, probably closer to 1% for all patients; Risk of SCD higher in children may be as high as 6% per year – Majority have progressive hypertrophy; Adults - 2-3% SCD per year, Adolescents - 4-6% SCD per year, Infants (less than 1 yr old), mortality = 50%; Clinical deterioration usually is slow; Progression to DCM occurs in 10-15%
What are risk factors for sudden cardiac death in HCM?
- Massive LVH (e.g > 30 mm)
- Family history of sudden death
- Unexplained/recurrent syncope
- Nonsustained VT (Holter Monitoring)
- Drop in blood pressure during exercise
How can HCM be treated?
Follow closely, implantable cardioverter-defibrillator if high risk of sudden death, meds if a fib or progressive heart failure symptoms
