Cardiomyopathies

Question 1

Dilated Cardiomyopathy

Answer 1

•most common — 60%
•dilated, globular, spherical shaped LV with decreased LV systolic function [diffuse dilation & systolic dysfunction w/ increased wall stress]
•MR from restriction of MV leaflets during systole (Type IIIb) — papillary muscles displaced to outside of heart
•etiology: idiopathic, peripartum, infection, genetic, toxins
•prognosis is poor:
50% mortality 2 years
75% mortality 5 years
25% improve
EDD > 4 cm/m^2 = higher mortality

Question 2

Hypertrophic Cardiomyopathy

Answer 2

•2nd most common
•autosomal dominant disease w/ variable penetrante and expression
•asymmetric hypertrophy — 4 different patterns (in all types the basal inferolateral or basal posterior wall is normal)
•outflow tract obstruction in 25% (HOCM, SAM)
—> turbulent flow in LVOT
—> MR w/ posterior directed jet (restricted leaflet with jet directed away from effected leaflet)
•all have diastolic dysfunction
•normal systolic function
•thick, stiff, non compliant myocardium that is metabolically challenged —> subendocardial ischemia & ventricular arrythmias w/ sudden death
•CWD — flow acceleration in late systole when heart is empty and LVOTO worst created dagger shaped profile
•M-mode — characteristic premature closure of AV leaflets

Question 3

Infiltrative (restrictive) cardiomyopathy

Answer 3

•least common
•etiology:
-Primary: Loeffler’s hypereosinophilic endocarditis, endomyocardial fibrosis, idiopathic
-Secondary: amyloidosis (most common), sarcoidosis, glycogen storage disease, hemochromatosis, drugs, radiation
•infiltration of abnormal substances within the myocardium — walls appear granular
•abnormal stiff non compliant myocardium
•all have diastolic dysfunction
•restrictive TM inflow velocities
•decreased mitral annular TDI velocities (lateral E’ < 8)
•initially normal systolic function and abnormal diastolic function
•prognosis related to thickness of walls, degree of diastolic and systolic dysfunction, development of symptoms —> 2-3 yr survival < 50%
•restrictive vs constrictive:
Lateral annular mitral tissue doppler differentiates
E’ > 8 cm/s in CP w/ normal myocardium
E’ < 8 cm/s in RICM

Question 4

4 different types of HOCM

Answer 4

• Sigmoidal 40-50%
• Reverse curve 30-40%
• Apical 10%
• Neutral 10%

*different shapes of LV cavity lead to different hydraulics and determine LVOTO