Flashcards in MHD: Cardiomyopathy Deck (38):
What is a cardiomyopathy?
A primary abnormality of the myocardium not attributable to pressure or volume overload. It involves a progressive impairment of the structure and function of the muscular walls of the heart chambers.
What are the 3 main types of cardiomyopathy?
Which type of cardiomyopathy is most common?
Describe the morphological changes seen in dilated cardiomyopathy
Biventricular dilatation causes contractile dysfunction
The myocardium compensates for the dilation with hypertrophy. Interstitial fibrosis can also develop.
Proteins of the ________ are involved with genetic forms of dilated cardiomyopathy
Proteins of the CYTOSKELETON are involved with genetic forms of dilated cardiomyopathy
What are the non-genetic causes of dilated cardiomyopathy?
Peripartum (due to elevated PRL)
What are the clinical consequences of cardiomyopathy?
What is hypertrophic cardiomyopathy?
Marked LV hypertrophy (septum>free wall)
AKA: IHSS, hypertrophic obstructive cardiomyopathy
How are diastole and systole affected by dilated cardiomyopathy compared to hypertrophic cardiomyopathy?
Systole is affected by dilated cardiomyopathy
Diastole is affected by hypertrophic cardiomyopathy
What is the classical shape of the ventricle in hypertrophic cardiomyopathy?
Banana shaped due to an enlarged intraventricular septum
Describe the histology of hypertrophic cardiomyopathy
Myocytes are hypertrophied and appear haphazardly organized. Interstitial fibrosis can also be seen.
What is the major cause of hypertrophic cardiomyopathy?
Most cases are familial
Autosomal dominant mutation in gene encoding sarcomeric proteins
Mechanically, dilated cardiomyopathy is a defect in ________ whereas hypertrophic cardiomyopathy is a defect in _________
Mechanically, dilated cardiomyopathy is a defect in FORCE GENERATION whereas hypertrophic cardiomyopathy is a defect in ENERGY TRANSFER
Clinical outcome of hypertrophic cardiomyopathy
Diastolic heart failure
Harsh systolic ejection murmur
Intractable heart failure
What is the most common cause of sudden death in young athletes?
What is the treatment for hypertrophic cardiomyopathy?
Medications to enhance ventricular contraction (beta blockers, calcium channel blockers)
Surgical excision of muscle
What is restrictive cardiomyopathy?
A primary decrease in ventricular compliance prevents ventricular filling (expansion) during diastole (systolic function is preserved)
Describe the morphological changes seen in restrictive cardiomyopathy
Enlarged left atrium with are normal LV cavity size, slightly thickened LV wall
What are the causes of restrictive cardiomyopathy?
Inborn errors of Metabolism
What is an amyloid?
A misfolded protein that desposits in the extracellular space causing tissue damage
What are the common features of amyloid deposits?
Beta pleated sheet configuration
Stain congo red in tissue that appears apple-green under polarized light
What is myocarditis?
Inflammation of the myocardium that causes myocardial injury
What are the causes of myocarditis?
Viral (Coxsakie A and B, cytomegalovirus, HIV)
Bacterial (Diptheria, Lyme disease)
Parasitic (Chaga's disease, trichinosis, toxoplasmosis)
Noninfectious (Immune hypersensitivity, rheumatic fever, giant cell myocarditis, sarcoidosis)
What is the clinical manifestation of the myocarditis?
Can cause acute congestive heart failure, arrhythmias and can progress to dilated cardiomyopathy
What liquids can be involved with pericardial effusion?
Serous fluid (clear or yellow)
How does the timing of pericardial effusion affect the clinical outcome?
Slowly developing may be clinically silent
Rapid or large effusions can compress the atria and vena cava (or ventricles in severe cases), leading to decreased cardiac filling
What is pericarditis?
Inflammation of the pericardium usually secondary to cardiac, thoracic or systemic process
What are the causes of pericarditis?
Infections (viruses, bacteria, TB, fungi, parasites)
Immune-mediated (rheumatic fever, SLE, post-MI)
What is fibrinous pericarditis?
"Bread and butter" pericarditis
The pericardial surface appears shaggy due to fibrinous exudate
Exam finding: pericardial friction rub
What is the cause of suppurative pericarditis?
Acute bacterial infection can lead to purulent surface of the percardium
What can cause hemorrhagic pericarditis?
What can cause caseous pericarditis?
Describe the presentation of pericarditis
Can be silent, or cause chest pain, systemic complaints
Friction rub is often found on physical exam
EKG changes: diffuse ST elevation
Describe the healing process of pericarditis
Focal plaque like thickenings
Constrictive pericarditis can cause the heart to be surrounded by a dense scar, which prevents expansion
What is the treatment of constrictive pericarditis?
Surgical removal of the scarred, constrictive pericardium
What are the complications of cardiac transplantation?
Acute or chronic rejection
Post tranplant lymphoma
Late progressive diffuse stenosing of coronary arteries
What is the success rate of cardiac transplantation?
70-80% 1 year survival
>60% 5 year survival