QuestionSBA
QuestionChoice
In a non-failing heart, the increased contraction of the ventricle clears the increased end-diastolic volume. This prevents a significant increase in right atrial pressure. However, in a failing heart, contraction cannot increase sufficiently, thus increasing right atrial pressure as insufficient blood is cleared. This causes the release of atrial natriuretic peptide from the atrium and B-type natriuretic peptide (BNP) from the ventricles. BNP and NT-pro-BNP are therefore used as markers of heart failure.
10001188
c
A significant rise in right atrial pressure
QuestionChoice
When pre-load is increased, the increased venous return causes the right atrium and ventricle to be more distended by the end of diastole. The contraction of the right ventricle is increased by this distension. Pulmonary venous return is increased by the same proportion, increasing the distension of the left ventricle. The same increase in contraction occurs, therefore increasing cardiac output to the same amount as the venous return.
10001187
b
Decreased cardiac output
QuestionChoice
The Anrep effect describes how increased stretch on a cardiomyocyte causes increased calcium entry into the cytoplasm, increasing the contraction of the ventricles. This explains why increased end-diastolic volume during increased pre-load causes increased contraction and increases cardiac output in accordance with Starling's law.
10001189
d
Decreased calcium entry into cardiomyocytes
QuestionChoice
When pre-load is increased, the increased venous return causes the right atrium and ventricle to be more distended by the end of diastole. The contraction of the right ventricle is increased by this distension. Pulmonary venous return is increased by the same proportion, increasing the distension of the left ventricle. The same increase in contraction occurs, therefore increasing cardiac output to the same amount as the venous return.
10001186
a
Increase in end-diastolic volume of the ventricles
QuestionChoice
Peripheral oedema would occur in a failing heart due to the inability of the heart to maintain a low right atrial pressure upon increased pre-load. This increases venous pressure and decreases re-absorption of fluid at the venous end of capillaries, resulting in peripheral oedema. Furthermore, the decreased ability to increase cardiac output in heart failure results in the renal retention of fluid, increasing pre-load further and worsening peripheral oedema.

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10001190
e
Peripheral oedema
Concept
Chapter
2693
3892
The Frank-Starling curve
Topic
159
Cardiovascular physiology
12784
According to Starling's law, an increase in pre-load in a non-failing heart will cause what?
a