Left Side Heart Failure

Question 1

Describe symptoms

Answer 1

Patient may have SOB
Particularly at night when lying flat when the systemic circulation has been returned to the heart
SOB during lying flat is called Orthopnea
Waking up at night SOB is called paroxysmal nocturnal dyspnea

Irratation of lung parenchyma can cause cough

Expectoration of frothy white secretions due to oedema

Reduced exercise tolerance due to all of the above

Question 2

What are the causes of left side heart failure

Answer 2

Hypertension: this causes unwanted non functional hypertrophy of the left ventricle reducing its ability to eject blood during systole.

MI: an area of non contractile scar tissue may be replaced this reduced ability to contract and stretch as frank starlings law.

Aortic valve stenosis: this could be caused due to hypertension but this further increases the pressure in the ventricles increasing the chance of hypertrophy

Aortic valve regurgitation: this causes an overload on the left ventricle because of too much volume. Hypertrophy

Question 3

What are the complications of left side heart failure

Answer 3

Increases pulmonary pressure which causes an increase burden on the right side of the heart.
Congestive heart failure

Question 4

Describe pathology

Answer 4

Right side still pumps blood to pulmonary circulation
Left side cannot pump to systemic circulation
There is an increase in pressure in left ventricles, this accumulates and eventually back pressure causes increase in blood volume in pulmonary circulation. Once the osmotic pressure of the blood has exceeded that of in the alveoli (capillaries normally 10, alveoli normally 25)
osmosis causes pulmonary oedema as fluid leaks into lung parenchyma