cardiomyopathies Flashcards
In DCM, is systolic dysfunction generalised or region-specific?
In humans the degree of systolic dysfunction depends on whether there is an ischaemic nature and the distribution of this. However, even non-ischemic DCM has a regional distribution of systolic dysfunction, usually with the proximo inferior and posterior walls having relatively preserved ejection fraction.
Causes of high-output cardiomyopathy ?
Tachycardia- mediated
Thyrotoxicosis
Nutritional ( beriberi, thiamine, taurine, L-aspartate deficiency)
peripheral right->left shunt lesions
Anemia
What types of concentric hypertrophy have been reported in humans?
Assymetric septal hypertrophy
Obstructive vs non obstructive
concentric hypertrophic
isolated apical hypertrophic
atypical hypertrophic
what are causes of DCM in humans?
Idipathic
Familial
Noncapmpacted myocardium
Peripartum
Hemochromatosis (iron overload)
Infectious
Toxic
what are causes of infectious DCM in humans
Postviral myocarditis
HIV
Legionella
Sepsis (gram negative)
what are toxic causes of DCM in humans ?
Adriamycin
alcohol
carbon monoxide
stimulant drugs (eg cocaine, amphetamines)
All anthracycline chemotherapy
what are causes of restrictive cardiomyopathy in humans?
Idiopathic
Infiltrative (amyloidosis, glycogen storage disease, hemochromatosis)
post-radiation
endocardial fibroelastosis
As DCM progresses, what chamber shape changes occur, and what are their effects?
We see spherification of the chamber which results in a reduction in contraction efficiency
What is the sphericity index?
It is a ratio which determines how spherical the ventricle has become in DCM and is a proxy for systolic dysfunction.
Normal hearts have long axis:minor axis of 1.6:1. A sphericity index of <1.5:1 implies pathological remodelling
How does functional mitral regurgitation occur in DCM?
As the chamber becomes more spherical you have lateral deviation of the papillary muscles and dilation of the annulus which result in defective coaptation -> regurgitation
what features may giveaway for ischaemic DCM?
Local segmental wall thinning at the site of the ischemia
What is EPSS?
The distance in millimiters of the valve from the anterior septum at maximal early opening of the mitral valve
How is EPSS an indirect estimator of ejection fraction ?
Lv dimensions are proportional to the diastolic left ventricular volume, and the maximal diastolic excursion of the mitral valve is proportional to itral stroke volume, the ratio of the two dimensions will be proportional the the ejection fraction
How is EPSS an indirect estimator of ejection fraction ?
Lv dimensions are proportional to the diastolic left ventricular volume, and the maximal diastolic excursion of the mitral valve is proportional to itral stroke volume, the ratio of the two dimensions will be proportional the the ejection fraction
What is ventricular non-compaction?
During development, the ventricle myocardium begins as a series of sinusoids that then compress, or compact, into organized myocardial fibers. Occasionally, this fails, and the foetal ventricular myocardium persists in the non compacted state which does not allow for adequate contraction or filling.
