Answer:
A- Heart failure may be caused by different health problems including high blood pressure or coronary artery disease
B- Systolic heart dysfunction is caused by the absence of normal heart contractions, while diastolic dysfunction is produced by dysfunction in the period of relaxation
C-These symptoms are because the heart can't pump blood well
D-The patient needs to eat low amounts of salt and saturated fats in order to decrease blood pressure
E- It has been shown that a low-salt diet helps to maintain a normal blood pressure. You can read this article by Hummel et al. (2009): "Recommendation of low-salt diet and short-term outcomes in heart failure with preserved systolic function. The American journal of medicine, 122(11), 1029-1036"
No, it's because we need to breathe. Your body needs oxygen. Air pressure has little to nothing to do with it as far as I know.
The arteries carry blood full of oxygen rich from the heart and the veins return oxygen-poor blood back to the heart