HF and hypertrophy Flashcards
The response of the heart to acute hemodynamic and adrenergic stimuli?
- Altered P/V relationships
- Altered inotropy
- Altered chronotropy
The adult heart is able to alter its_____ in response to chronic stresses
size and shape
physiological hypertrophy is caused by
chronic exercise or pregnancy
physiological hypertrophy will result in
- myocyte length increasedin more than width
- no fibrosis
- no cardiac dysfunction
pathological hypertrophy is caused by
chronic hypertension or
aortic calve stenosis
pathological hypertrophy will result in
- myocyte wider than it is long
- fibrosis
- can have cardiac dysfunction
Cardiac dilation is caused by
- myocardial infarction
- DCM
- pathological hypertrophy can also lead to this
Cardiac dilation is can lead to
- myocyte length increasing much more than width
- excessive fibrosis
- myocyte death
- advanced cardiac dysfunction
Myosin Heavy Chain Isoforms
- α and β MHC isoforms are found in the heart:
- The heterodimers (αα, αβ and ββ) have distinct ATPase activity (and functional properties)
- The ratio of these isoforms varies across species and throughout development
α and β MHC are encoded by
different genes and their expression is transcriptionally regulated
pathological hypertrophy results in ____ in ATPase and ___ in ___ MHC
decrease in ATPase
increase in BB MHC
physiological hypertrophy results in ____ in ATPase and ___ in ___ MHC
increase in ATPase
increase in aa MHC
Cardiac adaption is a
dynamic process that involves not only architectural but also structural modifications
In response to stress, both the
quantity and the quality of the contractile elements is altered
The heart has
phenotypic and genotypic plasticity
Programmatic alterations in gene and protein expression occur in response to
pathologic or physiologic triggers
The phenotypic adaptions may involve both
transcriptional and post-translational modifications
The functional adaptations are generally
adaptive but over time can result in ventricular dysfunction
LVH : Cellular mechanisms
- Likely increase in Ca current via L-type Ca channel
- Reduced SR pump fxn
(↑ PLB/SERCA2 ratio) - Impaired myofilament relaxation
- Altered (increased) cytosolic calcium and new steady-state
_____ is Sufficient to Correct Mechanical Defects in Cardiocytes From Patients with Heart Failure
SERCA2 Gene Transfer
Concept of positive feed-back mechanisms that ____
amplify disease severity
