Define cardiac preload and describe its determinants.
This question required synthesis and application of knowledge derived from multiple sources
rather than regurgitation of a published list in a text. Many candidates failed to recognise that
venous return is not the only determinant of preload. Most candidates failed to discuss
determinants of venous return. Factors such as contractility, afterload or chamber filling and
emptying can all impact preload. In addition to listing determinants the question required an
explanation of their relationship with preload (e.g. the direction of change).
A discussion about the determinants of cardiac output was not asked for as did not score marks.