Cardio 7 Flashcards
What is the number one cause of death for men and women?
Heart disease (8750 women per year)
How much is the onset of heart disease delayed in women and why?
~10 years - protected from heart disease pre-menopuase
What kind of women are more likely to have heart disease?
Diabetics
What is different about the costs and hospital stays for heart disease between men and women?
Women stay in hospital for longer but are less likely to have heart procedures and 20% more money is spent on men in hospital
What is PDE5 inhibitor efficacy dependent on and how does this affect treatment for women with heart disease?
It is oestrogen dependent so the women who are post-menopausal may not be receptive to the treatment (not good because this is the group of women who are most likely to develop heart disease)
What converts testosterone to oestrogen?
Aromatase
How do the levels of estradiol and testosterone change in males?
Estradiol increases gradually in males and stays stable through adulthood, testosterone increases in puberty and then stays at a high level and slowly reduces in late adulthood
How do the levels of estradiol and testosterone change in females?
In females estradiol increases from puberty to around 50 (menopause) and then drops to low levels, testosterone increases in puberty, but drops off later in life
What are the oestrogen receptors?
ER alpha, ER beta, GPER
What is the androgen receptor?
AR
What is the pathway for testosterone action?
Testosterone – AR – MAPK – phosphorylation of downstream targets – protein synthesis – hypertrophic growth – genomic effects
What is the effect of oestrogen on cardiomyocyte shortening?
Extent of shortening is less in females than males. The influence of oestrogen is to reduce the extent of contraction - due to smaller calcium transients. Calcium transient downregulated in the presence of oestrogen
What are men and women most likely to die of due to ischemia?
Men more likely to die of sudden cardiac death and pre menopausal women more likely to have subsequent heart failure
What is the downside of reperfusion in treating ischemia?
Reperfusion – calcium overload – contractile dysfunction (myocytes contract so hard that they rip open the sarcolemma and cell dies), fatal arrhythmias (erratic electrical activity and excitation), cardiomyocyte death
What happens after 25 mins of ischemia?
Substantial but not complete injury
What happens if the heart is vulnerable to ischemic damage?
It won’t recover
What happens if the heart is protected from ischemic damage?
It will recover well
What gender has a greater proportion of cardiac function recovery?
Females
What gender has reduced ventricular arrhythmias and necrotic activity?
Females
What happens to females after an ovariectomy?
Loss of ischemic cardioprotection
What are the features of the langendorff perfused heart?
Retrograde flow - drainage into coronary vessels
What is the amount of oestrogen dependent on?
Amount of testosterone
What does bone production of oestrogen protect against?
Osteoperosis in males
What cardiac region produces oestrogen?
Ventricle and pericardial fat
What is the expression of aromatase dependent on?
Age, sex, disease state of heart
What happens to the level of aromatase in the ventricle (age and sex)?
Greater in females and greater with age
What happened when aromatase was increased in males and reduced in females?
Males - reduced recovery
Females - increased recovery
What is important to maximise potential for recovery?
Crucial to get the right balance of testosterone and oestrogen to maximise potential for recovery
What structure is estradiol important for?
Prostate
What are the pathways in ECC?
- Calcium in L type channels
- Calcium out via ATP
- 1 Calcium out 3 Na in
- 3Na out 2 K in
- H out Na in
Why do females have less contraction in myocytes?
Oestrogen reduces contraction by reducing calcium transients and inhibiting myocyte handling
What % of Australians have heart failure and what % have CVD?
1.3%
17%
