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
