MVO2 Determinants HR Wall Tension — FRCA Primary MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: C — Heart rate / wall tension (preload and afterload) / and contractility
Myocardial O2 demand is determined by: heart rate (most important — determines both demand and diastolic perfusion time) / wall tension (Law of Laplace: T = P×r/2h — influenced by preload and afterload) / contractility (inotropy). The rate-pressure product (HR × systolic BP) is a clinical estimate of myocardial O2 demand.
Reference: Power Kam 2018 Principles of Physiology for the Anaesthetist