Cardiomyopathy, Myocarditis, Pericardial Disease Flashcards
What is cardiomyopathy?
Primary abnormality of the myocardium not attributable to pressure or volume overload
What is the most common cardiomyopathy? Least common?
Most common: Dilated
Least common: Restrictive
Dilated Cardiomyopathy
What is the dysfunction?
Contractile (SYSTOLIC) dysfunction.
Causes 4 chamber dilatation of the heart and biventricular failure
What are some causes of Dilated Cardiomyopathy?
Myocarditis Peripartum Cardiomyopathy Toxic (alcohol, doxorubicin) Idiopathic Genetic
Genetic disorders affecting what cellular component may cause dilated cardiomyopathy?
Cytoskeleton of the myocytes
What are long term complications of dilated cardiomyopathy?
Progressive systolic CHF
Arrhythmias
Mural thrombi with emboli
Hypertrophic Cardiomyopathy is AKA…
IHSS = idiopathic hypertrophic subaortic atenosis HOCM = Hypertrophic obstructive cardiomyopathy
Hypertrophic Cardiomyopathy
What is the dysfunction?
Marked LV myocardial hypertrophy (particularly in the septum), leading to abnormal DIASTOLIC filling and diastolic HF
Which part of the ventricular wall is typically hypertrophied in hypertrophic cardiomyopathy?
Septum
Which cardiomyopathy leaves a “banana shaped LV cavity?”
Hypertrophic Cardiomyopathy
Hypertrophic Cardiomyopathy
What do the myocytes look like histologically?
Myocytes are hypertrophied and haphazard.
Commonly see interstitial fibrosis
What is the etiology of Hypertrophic Cardiomyopathy?
Most cases are genetic (familial)
Autosomal dominant
Where do most genetic mutations causing Hypertrophic Cardiomyopathy effect the cell?
Most mutations are in genes encoding proteins in the sarcomere
Long Term Complications and Risks of Hypertrophic Cardiomyopathy
- Diastolic HF
- High risk for ventricular and atrial arrhythmias (most common cause of sudden death in young athletes)
- Exertional dyspnea
- Anginal pain
Hypertrophic Cardiomyopathy
Treatment
Medical therapy (beta blockers) to enhance relaxation of ventricle
Surgical excision of muscle (septum)
Restrictive Cardiomyopathy
What is the primary dysfunction?
Decrease in ventricular compliance, impeding LV filling during diastole
Causes of Restrictive Cardiomyopathy
Idiopathic
Radiation Therapy
Sarcoidosis (non caseating granulomas developing in the heart)
Amyloidosis
What is an amyloid?
Abnormally folded protein that begins to deposit into extracellular spaces, causing tissue damage
In what secondary protein structure are amyloids arranged?
Beta pleated sheets
What stain can be used to identify amyloids? How would amyloid appear under normal light with this stain? Under polarized light?
Congo Red Stain
Appears salmon pink under normal light.
Appears apple-green under polarized light
What is myocarditis?
Inflammatory process resulting in myocardial injury
What is the most common cause of myocarditis?
Viral infection, particularly Coxsackie A and B
Cytomegalovirus and HIV also can be causes
Can also be cause by bacteria (diptheria, Lyme) or parasites (Chagas)
What are some noninfectious causes of myocarditis?
Immune mediated (hypersensitivity, rheumatic fever) Giant cell myocarditis Sarcoidosis
What are the clinical manifestations of myocarditis?
Wide spectrum, could be asymptomatic or nonspecific (fever, fatigue).
Acute congestive heart failure
Arrhythmias
Progression to dilated cardiomyopathy
Pericardial Effusion
What might you see in a pericardial effusion in the case of trauma?
Bloody pericardial effusion
Pericardial Effusion
What might you see in a pericardial effusion in the case of an infection?
Pus (dead PMNs)
Pericardial Effusion
What might you see in a pericardial effusion in the case of serious heart failure?
Yellow, clear serous fluid
Above what volume will a pericardial effusion become clinically significant?
500 mL
Note: a rapid increase in fluid, even below 500mL, may still cause hemodynamic instability
As a pericardial effusion grows, what happens?
First, you get compression of the atria and the vena cavae. Soon, you gte compression fo the ventricles, leading to less filling of the ventricles during diastole and decreased outflow
What is pericarditis?
Inflammation of the pericardium, usually secondary to another problem
What is fibrinous pericarditis? What might you hear on auscultation? How will the pericardial surface appear?
Lots of fibrin deposited in the pericardium
Hear a pericardial friction rub
The surface will appear irregular and shaggy
What might cause hemorrhagic pericarditis?
Tuberculosis
Malignancy
What might cause caseous pericarditis?
Tuberculosis
What might cause suppurative pericarditis?
Bacterial infection
What are the symptoms of pericarditis?
Could be silent
Chest Pain
Systemic complaints
Friction rub heard on auscultation
EKG Changes – diffuse ST segment elevation
Healing of the pericardium in pericarditis can lead to what?
CONSTRICTIVE pericarditis
Heart surrounded by a dense scar, limiting diastolic expansion of the heart
How can one treat constrictive pericarditis?
Pericardiectomy
Which cardiomyopathies may be treated by heart transplant?
Dilated cardiomyopathy
Ischemic cardiomyopathy
What are some complications of heart transplant?
Need chronic immunosuppressive therapy
Higher risk of infection
Acute and chronic rejection
EBV infection could lead to lymphoma or malignancy
Aggressive intimal thickening of the coronary arteries
How are heart biopsies obtained?
Enter through a large vein, travel through the SVC, go into the RA, them RV, biopsy the SEPTUM.
Do not biopsy the RV free wall because that is thinner and you may puncture it
