8/7- Cardiomyopathies Flashcards
(38 cards)
What is cardiomyopathy?
Genetic or acquired primary disease of the myocardium
What are the different subtypes of cardiomyopathy?
- Dilated
- Hypertrophic
- Restrictive
What is the equation for ejection fraction?
What is a normal value
EF = SV/EDV x 100%
EF is about 50-75%
What is dilated cardiomyopathy (DCM)?
- Which chambers affected
- Progressive?
- Arrhythmias
- Consequences
Ventricular dilation and impaired systolic function: congestive heart failure
- 1 or both ventricles are affected (more often L or both; rarely R alone)
- Generally progressive
- Atrial and ventricular arrhythmias are common
- Sudden death may occur at any age
What is the main problem in dilated cardiomyopathy as opposed to hypertrophic and restrictive?
Dilated involves decreased systolic function and ejection fraction while hypertrophic and restrictive have more problems with diastole since stiffer ventricles are harder to fill
What are some (potentially reversible) causes of dilated cardiomyopathy?
- Alcohol
- Ischemia
- Hypertension
- Cocaine
- Medications
- Endocrine
- Nutritional
- Electrolyte imbalance
- Iron (hemachromatosis or congenital anemias)
- Tachycardia
- Sleep apnea
- Infections (Chagas/viral)
- Autoimmune
- Sarcoidosis
**Most common causes
What is the pathophysiology behind alcohol causing ___ cardiomyopathy? Reversible or irreversible?
Alcohol -> DCM
- Associated with heavy, prolonged use
- Often evident as asymptomatic LV dysfunction
- Direct toxic effects of alcohol and nutritional deficiencies; in addition to a higher than expected incidence of HTN
**Potentially reversible after alcohol abstinence!**
What is the pathophysiology behind ischemia causing ___ cardiomyopathy? Reversible or irreversible?
Ischemia -> DCM
- Revascularization restores function in chronically ischemic (hibernating) myocardium
Practical implication:
- Coronary angiography or stress testing is recommended in most pts presenting with dilated cardiomyopathy to exclude or confirm CAD as a possible etiology
(b/c it is potentially treatable)
What are some (irreversible) causes of DCM?
- Idipoathic
- Post MI Scarring
- Familial
- HIV
**Differentiate between hibernation and scarring**
What may cause hypertrophic cardiomyopathy (HCM)? Characterstics? Involves what?
Genetic disease
- Autosomal dominant
- Involves sarcomere
What are the different phenotypes of HCM?
There are numerous phenotypes of HCM
- Obstructive
- Non-obstructive
- Regional
What physical characteristics are seen in HCM?
- Problem with what function of the heart?
- Arrhythmias?
- Consequences?
- Thick walls and filling abnormalities
- Arrhythmias common
- Sudden death at a younger age
What does this show?
Apical HCM
- Hypertrophy mainly at ventricular apex
- Classic T wave inversions on EKG
- “Yamaguchi syndrome”
- Thought to be a more benign variant of HCM
- Not too much trouble with ventricle emptying (since apex is mainly affected), but may become symptomatic in later stages
What does this show?
Asymmetric septal hypertrophy (ASH/IHSS)
Characteristics of HCM: SAM (systolic anterior motion) and LVOT (left ventricular outflow tract) obstruction
- Altered left ventricle geometry
- Abnormal mitral valve pathology: long anterior MV leaflet
- Venturi effect: systolic anterior motion of the mitral leaflet: SAM (if leaflet flows through restricted area, turbulence increases but pressure decreases, sucking leaflet towards the septum where it may hit and transiently stop blood)
What is this showing?
SAM and LVOT (with HCM?)
- Very mosaic pattern is turbulence created in obstruction in LVOT
- Left ventricular pressure must increase significantly to push blood through this obstruction
Pressure characteristics of HCM with SAM and LVOT?
- Higher ventricular pressure proximal to the LVOT compared to the aortic valve
- May help differentiate from aortic stenosis???
What are some clinical manifestations of HCM?
Symptoms are common; there is impaired filling of the heart
- Dyspnea
- Chest pain
- (Pre)syncope
- Outflow obstruction:at rest or with exertion only
- Arrhythmias
- Fatigue
- Edema
- Normal systolic function
- Mitral insufficiency
Dyspnea, palpitations, syncope, chest pain in about 30-50%
What is the natural history of HCM?
Bimodal:
- Early developing during puberty
- Later evident age > 60 yo
Annual mortality is about 2% (4-6% during adolescence)
- Most deaths are sudden: ventricular arrhythmias (may start as SVT); exertional
Endocarditis
What is restrictive CM (RCM)?
- Non-dilated ventriclewith normal wall thickness (or increased) and systolic function
- Dilated atria
- Myocardium is rigid; ventricles fill at high pressures only (diastolic dysfunction)
Causes of restrictive CM?
- Idiopathic
- Amyloidosis
- Sarcoidosis
- Hemochromatosis (often dilated CMP)
- Radiation
- Hypereosinophilic syndrome
- Endomyocardial Fibrosis
- Chloroquine therapy
How does restrictive CM present?
Any age
Dyspnea and edema most common!
- High venous pressures
—Elevated jugular venous pressures
—Pulmonary venous congestion
Later: fatigue, weakness with low CO
Comparison of cardiomyopathies in terms of LVEF, WTH, LVEDV, and LA size
Anatomy of cardiomyopathies
Congestive
- Dilated LV
- Decreased systolic function
Restrictive and hypertrophic
- Normal LV size
- Normal or increased systolic function
- Decreased diastolic function
