Myocardial hypertrophy

Question 1

Characteristics of HF on individual cell level

Answer 1

Myocyte loss, myocyte dysfunction and fibrosis

Question 2

What are the 2 targets of HF therapies?

Answer 2

Improve the work load of the heart
- e.g. dilating blood vessels so heart is pumping against reduced resistance
Improve the neurohumoral milieu,
- block increase activity of catacholamines that is characteristic of HF
but do not correct on myocyte level

Question 3

What is concentric hypertrophy

Answer 3

Thickening on LV free wall, intraventricular septum

Can even be right sided and with atrial dilatation

Question 4

Components of concentric hypertrophy

Answer 4

• Myocyte enlargement
• reprogramming of gene expression
• fibrosis
• dysfunction

Question 5

Pathway of getting from normal heart to dilated

Answer 5

Usually through concentric hypertrophy
- apoptosis increased in failing hearts compared to those with CH
but can be direct
Both have stimulus of mechanical load, ichemiac injury or mutations

Question 6

Cell muscle number as a therapeutic target: what are the 4 strategies

Answer 6

1. Block cell death itself/ provide cell survival signals
2. grafting cells that make heart muscle - pluripotent stem cells/endogenous cardiac stem/progenitor cells
3. Directly programming non muscle cells to become myocytes
4. Stimulate proliferation - block cell cycle inhibitors/ induce cell cycle activators