Regulation of cardiac output: preload, afterload, contractility and Frank-Starling
How heart rate, preload, afterload and contractility set cardiac output, the Frank-Starling and venous return curves, wall stress, SVR and Fick calculations, and how these explain heart failure treatment, shock haemodynamics and fluid responsiveness.
Tier 1Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Cardiac output = heart rate × stroke volume, about 5 L/min at rest (cardiac index 2.5 to 4 L/min/m²). It can rise about fivefold in exercise.
- Stroke volume depends on preload (end-diastolic stretch), afterload (wall stress during ejection) and contractility (force at a given preload and afterload).
- The Frank-Starling curve links preload to stroke volume. The heart failure curve is flatter and lower.
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Sources
- Maas JJ, Pinsky MR, Geerts BF et al. Estimation of mean systemic filling pressure in postoperative cardiac surgery patients with three methods. Intensive Care Med 2012;38:1452-60Intensive Care Medicine, 2012
- Guyton and Hall Textbook of Medical Physiology (14th ed.)Elsevier (Hall and Hall, 2021), 2021
- Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine (12th ed.)Elsevier (Libby et al., 2022), 2022
- Prediction of fluid responsiveness: an updateAnnals of Intensive Care 2016;6:111 (Monnet, Marik and Teboul), 2016
- Consensus on circulatory shock and hemodynamic monitoring. Task force of the European Society of Intensive Care MedicineIntensive Care Medicine 2014;40:1795-1815 (Cecconi et al.), 2014
- Last updated
- 14 November 2026
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