A 70 year old woman complains that she can no longer do her housework or climb the stairs without frequent rests;and she gets very breathless. Her ankle swells as the day progresses, but improve after a nights rest.

On examination the doctor notes that her breathing is rapid, chest auscultation reveals basal crackles. Pulse is regular and arterial pressure normal. Central venous pressure of 18cmH2O.

Chest X ray shows cardiothoracic ratio of 0.69,congested pulmonary vessels and thin horizontal lines of intercepted oedema. ECG is normal.

a) what is the diagnosis

b) what are the chief roles of starling forces in humans

c) what key intracellular parameter triggers cardiac contraction and how does it change in cardiac failure

d) how can cardiac contractility be assessed in humans

e) what causes crepitation of the lungs

f) why does the ankle swelling get worse during the day.