Cardiomyopathy Flashcards
What is cardiomyopathy a result of?
Heart disease resulting from a primary abnormality in the myocardium - primary abnormalities are of the vasculature and valves, not the myocardium
What are the 3 patterns of cardiomyopathy?
i. Dilated Cardiomyopathy
ii. HypertrophicCardiomyopathy
iii. Restrictive Cardiomyopathy
What is the most common cardiomyopathy?
Dilated Cardiomyopathy
What is dilated cardiomyopathy?
It is contractile (systolic) dysfunction that results in 4 chamber dilatation resulting in a heart that is 2-3x normal weight.
What are the 5 major etiologies of dilated cardiomyopathy?
- Post myocarditis
- Alcohol
- Peripartum cardiomyopathy
- Genetic
- Doxorubicin and Daunarubicin therapy
*6. Idiopathic
What do genetic abnormalities that lead to cardiomyopathy normally affect?
Genetic abnormalities most commonly affect the cytoskeleton
How can iron overload cause dilated cardiomyopathy?
Iron accumulates within myocytes and interferes with metal-dependent enzyme systems
What is the treatment for dilated cardiomyopathy?
Medical management of systolic heart failure and heart transplantation may be the option for patients whose
symptoms are recalcitrant to optimal medical therapy and who are appropriate candidates
What are the other names for hypertrophic cardiomyopathy?
“Idiopathic hypertrophic subaortic stenosis”
“Hypertrophic obstructive cardiomyopathy”
What is the cause of hypertrophic cardiomyopathy?
Caused by missense mutation in 1 of at least 12 genes encoding cardiac sarcomere proteins that leads to greater septum hypertrophy causing abnormal diastolic filling with marked LV hypertrophy
What is the shape of the LV in hypertrophic cardiomyopathy?
Banana shaped
What are the histologic features of hypertrophic cardiomyopathy?
Myocytes are haphazard and disorganized as well as hypertrophied
What is the type of heart failure found in dilated heart failure?
Systolic
What is the type of heart failure found in hypertrophic cardiomyopathy?
Diastolic
What are some of the clinical features of hypertrophic cardiomyopathy?
Dyspnea Harsh systolic murmur Anginal pain Intractable heart failure Arrhythmia
What is the most common cause of sudden death in young athletes?
Hypertrophic cardiomyopathy
What are the treatments for hypertrophic cardiomyopathy?
- Medical therapy aimed at enhancing ventricular relaxation so that diastolic filling is enhanced
- Surgical septal excision
What is restrictive cardiomyopathy?
Primary decrease in ventricular compliance, resulting in impaired ventricular filling during diastole. Systolic function is unaffected
What are some of the possible causes restrictive cardiomyopathy?
Radiation fibrosis
Amyloidosis
Sarcoidosis
What are the size changes of the heart in restrictive cardiomyopathy?
There generally are none as the LV is often normal in size
What is amyloidosis and how does it lead to restrictive cardiomyopathy?
Results from pathologic proteinaceous substance that is due to misfolding that is deposited in the myocardial interstitium that leads to impeded LV filling due to stiffness although it is normal in size
What are the histological and molecular features of amyloidosis?
They have a congo-red stain with an apple-green birefringence under polarized light.
They are often ß-pleated sheet
What is myocarditis?
Inflammation that causes myocardial injury
What are the infectious causes of myocarditis?
• Viruses – Enteroviruses - Coxsakie A and B – Cytomegalovirus – Human immunodeficiency virus • Bacteria – Diptheria – Borellia burgdorgeri - Lyme disease • Parasites – Trypanasoma cruzi (Chaga’s disease) – Trichinosis – Toxoplasmosis
What is the most common cause of myocarditis in the US?
Coxsakie A and B
What are the non-infectious causes of myocarditis?
- Immune mediated hypersensitivity as a side effect from rheumatic fever
- Giant cell myocarditis
- Sarcoidosis
What are some of the findings in myocarditis?
- Normal or flabby heart with mottled myocardium
- Interstitial inflammatory infiltrate
What are the clinical manifestations in myocarditis?
There is a range from asymptomatic to fever, acute CHF, arrhythmia and sudden death, and progressive dysfunction of the heart leading to dilated cardiomyopathy
What is pericardial effusion?
Accumulation of fluid in the pericardial sac that can show as a globular enlargement of heart on CXR
What is the level of pericardial effusions that may not be clinically significant?
Less than 500 mL
What is the problem with rapid accumulation of pericardial effusion or in very large amounts of fluid?
Can lead to serious symptoms: – Compress atria and vena cavae – Compress ventricles – Restrict cardiac filling – Cardiac tamponade
What is pericarditis?
– Inflammation of pericardium
– Usually secondary to cardiac, thoracic, or
systemic process
What are some of the causes of pericarditis?
– Infections – Immune-Mediated Reactions – Uremia – Neoplasia – Trauma – Radiation
Fibrinous Pericarditis Findings and Causes
• Pericardial surface irregular, “bread and butter” - friction rub can be heard
– Acute viral pericarditis
– Uremia
– Acute rheumatic fever
Suppurative Pericarditis Findings and Causes
• Acute bacterial infection
– Extension
– Seeding
Hemorrhagic Pericarditis Causes
Tuberculosis
Caseous Pericarditis Causes
Tuberculosis
What EKG changes can be seen with pericarditis?
Diffuse ST elevation
What is Dressler’s Syndrome?
It is an autoimmune phenomenon resulting in pericarditis several weeks post myocardial infarction.
What are some clinical findings with pericarditis?
- Wide spectrum - clinically silent to chest pain to systemic complaints (fever, chills)
- Pericardial friction rub (particularly with fibrinous pericarditis)
What is constrictive pericarditis?
Pericardial space is obliterated by dense scar tissue through the healing process which leads to limitations during diastolic expansion reducing cardiac output
When is constrictive pericarditis typically seen?
Seen particularly with TB, suppurative pericarditis
What is the treatment for constrictive pericarditis?
Pericardiectomy, surgical removal of constricting pericardium
How are heart biopsies obtained?
Septal endomyocardium biopsied
A 56-year old woman presents with episodes of chest pain during the past week. On physical exam she is afebrile; pulse 110/minute, regular; respirations 18; BP 100/68. Neck veins are distended to the angle of the jaw while sitting. On auscultation the heart sounds are distant. Lungs are clear. There is a 1.2cm irregular brown skin lesion on the left shoulder. CXR shows cardiomegaly and prominent borders on the left and right sides of the heart. Which of the following would you now order? A. ASO titer B. Biopsy of the skin lesion C. Coronary angiogram D. Echocardiogram E. Exercise stress test
D. Echocardiogram
Echocardiogram is done and shows a large pericardial effusion with diastolic collapse of the right atrium and ventricle. A pericardiocentesis yields bloody fluid. Which of the following is the most likely underlying cause of these findings?
A. Coronary artery atherosclerosis with thrombosis
B. Alcohol
C. Metastases
D. Rheumatic heart disease
E. Tuberculosis
C. Metastases
What are the main complications of cardiac transplantation?
i. Acute rejection
ii. Chronic rejection (graft arteriopathy)
iii. Infections
iv. Post-transplant lymphoproliferative disorder (Epstein Barr virus related)
What are the main indications for cardiac transplantation?
Most common indications – dilated cardiomyopathy, chronic ischemic heart disease
What is the most common primary tumor of the heart?
Myxoma
What is the most common location of myxomas?
Left Atrium
What is the appearance of myxomas like?
Gelatinous
What are the major complications of myxomas?
• Ball-valve obstruction
– Pedunculated lesions move into or through AV valves during systole that is position dependent
• Embolization
What are angiosarcomas and their origin cells?
- Malignant, aggressive
* Arise from endothelial cells
What is the most common PEDIATRIC tumor of the heart?
Rhabdomyoma
What are the complications of rhabdomyomas?
• Obstructs valvular orifice or cardiac chamber - they may spontaneously regress
