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Flashcards in Acute stress Deck (10)
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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


Myosin isoform and ATPase shifts are seen in

phenotypically distinct models of cardiac hypertrophy


pathological hypertrophy changes are

1. myocyte length increases LESS than the width
2. fibrosis
3. potentially cardiac dysfunction
4. decrease in ATPase
5. increase in BB MHC


physiological hypertrophy changes are

1. myocyte length increases MORE than width
2. NO fibrosis
3. NO cardiac dysfunction
4. increase in ATPase and aa MHC


contemporary view on heart changes

1. Cardiac adaption is a dynamic process that involves not only architectural but also structural modifications
2. In response to stress, both the quantity and the quality of the contractile elements is altered
3. The heart has phenotypic and genotypic plasticity
4. 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 mechanism

1. Likely increase in Ca current via
L-type Ca channel
2. Reduced SR pump fxn
(↑ PLB/SERCA2 ratio)
3. Impaired myofilament relaxation
4. Altered (increased) cytosolic calcium and new steady-state


SERCA2 Gene Transfer is Sufficient to

Correct Mechanical Defects in Cardiocytes From Patients with Heart Failure