Flashcards in Heart Failure and Hypertrophy (Chronic Cardiac Adaptation) Deck (13):
What MHC isoforms are found in the heart?
α and β MHC isoforms
T or F: different MHC heterodimers have distinct ATPase activity
True, and functional properties
How is the expression of α and β MHC regulated?
What changes are seen in phenotypically distinct models of cardiac hypertrophy?
Myosin isoform and ATPase shifts
What specific changes are seen in pathological hypertrophy?
Decrease in ATPase
and increase ββ MHC
What specific changes are seen in physiological hypertrophy?
Increase in ATPase
and in αα MHC
What causes pathological hypertrophy?
Aortic valve stenosis
What causes physiological hypertrophy?
T of F: In response to stress, both the quantity and the quality of the contractile elements is altered
The phenotypic adaptions may involve what?
both transcriptional and post-translational modifications (Most imp point in this lecture)
T or F: The functional adaptations can lead to ventricular dysfunction over time
What are the cellular mechanisms behind left ventricular hypertrophy (LVH)?
-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