11 18 2014 Cardiomyopathies Flashcards
What are the 3 types of cardiomyopathies
- dilated
- restrictive
- hypertrophic
Dilated cardiomyopathy
Clinical signs?
ventricular chamber enlargement with impaired systolic contractile function
– eccentric hypertension of ventricle
- low forward cardiac output
- fatigue
- lightheadedness
- exertion dyspnea (pulmonary congestion)
- increased risk for thrombotic events
Hypertrophic cardiomyopathy
abnormally thickened ventricular wall with abnormal diastolic relaxation; but usually intact systolic function
restrictive cardiomyopathy
abnormal stiffening of the myocardium leading to impaired diastolic relaxation but systolic contractile function is normal or near normal.
Causes of dilated cardiomyopathy
- viral myocarditis: immune related injury – myocardial distraction and fibrosis
- genetic
- toxic: alcohol (excessive) or doxorubin
Physical Examination of a person with dilated cardiomyopathy?
- cool extremities (owing to peripheral vasoconstriction)
- low arterial pressure
- tachycardia
- rales (pulm)
- S3 is common
- mitral valve regurgitation
Diagnosis of Dilated cardiomyopathy
- chest radiograph
- ECG
- Echo
- enlarged cardiac silhouette
- atrial and ventricular enlargement, arrhythmias (atrial and ventricular: due to damage to muscle fibers)
- 4 chamber cardiac enlargement with little hypertrophy
Treatment for dilated cardiomyopathy
TRANSPLANT (for those that qualify)
- treatment for heart failure
- treatment for arrhythmias
- treatment for thromboembolic events
Clinical findings for hypertrophic cardiomyopathy
- presentation is mid-20’s
- young athletes
- Angina
- Syncope due to arrhythimas (structural abnormalities)
- dyspnea (due to mitral regurgitation)
Physical exam findings for hypertrophic cardiomyopathy
- S4 – due to a non-compliant heart.
- obstruction: crescendo-descrescendo heard beast at the left lower sternal border
- Apex : holosystolic blowing murmur accompanying mitral regurgitation
- Valvular maneuver (“bear down”) increase in inter thoracic pressure decreases venous return and reduces LV size = enhances obstruction murmur.
Causes of hypertrophic cardiomyopathy?
What does it do to the ventricle?
- familial disease – autosomal dominant
- mutation in sarcomere complex (beta-myosin heavy chain, cardiac troponins, and myosin binding protein C) - asymmetric left ventricular hypertrophy that is not caused by chronic pressure overload.
- systolic LV contractile function is vigorous but the thickened muscle is stiff.
MOST COMMON: asymmetric hypertrophy of the ventricular septum
- extensive disorganization of myocardial fiber pattern.
- reduces the compliance and diastolic relaxation of the chamber
Treatment for hypertrophic cardiomyopathy
- beta blockers
- calcium channel antagonists
- anti-arrhythmias
- surgical therapy ( myomectomy) for patients whose symptoms do not respond adequately to medicine
Diagnostic fo hypertrophic cardiomyopathy
- ECG
- Echocardiography
- cardiac catheterization
- left ventricular and atrial enlargement with a Q wave that is prominent in inferior and lateral leads
- degree of LVH
- pressure gradient
Restrictive cardiomyopathy
- how common are they
- anatomy– characterization
- Cause?
- less common that DCM and HCM
- Characterized by abnormally rigid ventricles with impaired diastolic filling but usually normal or near normal systolic function.
* not necessarily thickened walls - Amyloidosis
* use congo red stain to see amyloid fibril deposits (misfolded proteins)
Amyloidosis
- primary
- secondary
- hereditary
- senile amyloidosis
- caused by deposition of immunoglobulin light chains AL fragments secreted by a plasma cell tumor
- presence of AA amyloid due to chronic inflammation ( ex. rheumatoid arthritis)
- autosomal dominant
- happens in elderly patients and they are scattered throughout the vascular system and other systems
Cardiac size on chest radiograph of restrictive cardiomyopathy
usually normal
ECG of restrictive cardiomyopathy will show what?
usually normal systolic contraction; “speckled” appearance in infiltrative disorders
Clinical findings of restrictive cardiomyopathies
- decreased CO
- Fatigue
- Systemic congestion = JVP, peripheral edema, palpable liver (tender)
- Arrhtyhmias : atrial fibrillation
- cardiac conduction block
Physical examination for restrictive cardiomyopathy
signs of right heart failure:
- Systemic congestion = JVP, peripheral edema, palpable liver (tender),
- Rales
Treatment for restrictive cardiomyopathy
phlebotomy and iron chelation therapy
- vasodialtors DO NOT WORK
- anticoagulants since intraventriuclar thrombus formation is common
