Cardiomyopathy Flashcards
What is cardiomyopathy?
Group of myocardial diseases that result in cardiac dysfunction.
What are the three types of Cardiomyopathy?
- Dilated Cardiomyopathy
- Hypertrophic Cardiomyopathy
- Restrictive Cardiomyopathy
What is Dilated Cardiomyopathy?
Dilation of all four chambers of the heart
What is the most common form of cardiomyopathy?
Dilated Cardiomyopathy
What does dilated cardiomyopathy result in?
Systolic dysfunction (ventricles can’t pump), leading to biventricular CHF
What complications are associated with dilated cardiomyopathy?
Mitral and tricuspid valve regurgitation and arrhythmia!
What is the most common cause of dilated cardiomyopathy?
Idiopathic
What are other causes of dilated cardiomyopathy?
- Genetic mutation (usually autosomal dominant)
- Myocarditis
- Alcohol abuse
- Drugs (e.g. Doxorubicin & cocaine)
- Pregnancy –> seen during late pregnancy or soon (weeks to months) after childbirth
- Hemochromatosis
What is the pathogenesis of Myocarditis that leads to dilated cardiomyopathy?
Usually due to Coxsackie A or B
- Characterized by lymphocytic infiltrate to the myocardium
- Results in chest pain, arrhythmia with sudden death or heart failure
- Dilated cardiomyopathy is a late complication
Side note: What is Hemochromatosis?
Excess body iron leading to deposition in tissues (hemosiderosis) and organ damage (hemochromatosis)
–> tissue damage is mediated by generation of free radicals
Side note: What causes Hemochromatosis?
Due to autosomal defect in iron absorption (primary) or chronic transfusions (secondary)
–> Primary hemochromatosis is due to mutations in the HFE gene, usually C282Y
Side note: What does Hemochromatosis present with?
Late adulthood
- Classic triad = cirrhosis, secondary diabetes mellitus, and bronze skin
- Other findings: dilated cardiomyopathy, cardiac arrhythmias, gonadal dysfunction (due to testicular atrophy)
Side note: What do labs show in Hemochromatosis?
Inc. ferritin, Dec. TIBC, Inc. serum iron, Inc. percent saturation
Side note: What does liver biopsy show in Hemochromatosis?
Accumulation of brown pigment in hepatocytes
-Prussian blue stain distinguishes iron (blue) from lipofusion
Side note: What cancer is associated with hemochromatosis? How do you treat hemochromatosis?
- Increased risk of hepatocellular carcinoma
- Treatment is phlebotomy
What is Hypertrophic Cardiomyopathy?
Massive hypertrophy of left ventricle
Who usually has hypertrophic cardiomyopathy?
Young athletes
What causes Hypertrophic Cardiomyopathy?
- Usually due to genetic mutations in sarcomere proteins
- Most common form is autosomal dominant
What are the clinical features of Hypertrophic Cardiomyopathy?
- Decreased cardiac output - Left ventricular hypertrophy leads to diastolic dysfunction (ventricle cannot fill)
- Sudden death due to ventricular arrhythmias - hypertrophic cardiomyopathy is a common cause of sudden death in young athletes
- Syncope with exercise - Subaortic hypertrophy of the ventricular septum results in functional aortic stenosis
What does biopsy show in Hypertrophic Cardiomyopathy?
Myofiber hypertrophy and disarray
What is restrictive cardiomyopathy?
Decreased compliance of the ventricular endomyocardium that restricts filling during diastole
What are causes of restrictive cardiomyopathy?
-Amyloidosis, Sarcoidosis (hemochromatosis), fibroelastosis (children), and Loeffler syndrome (endocardial fibrosis with an eosinophilic infiltrate and eosinophilia)
How does restrictive cardiomyopathy present?
Presents as CHF
What do you see on EKG with classic restrictive cardiomyopathy?
Low voltage EKG with diminished QRS amplitude
