Describe the factors affecting left ventricular function

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College Answer

Candidates often misinterpreted the question and described determinants of cardiac output. The answer should have focussed on factors affecting/contributing to normal LV function - not pathological states. Some answers showed a lack of appreciation that normal left ventricular function is afterload independent, due to compensatory reflexes. Answers needed to consider intrinsic and extrinsic factors affecting LV function - the latter (e.g. SNS, PSNS, hormones, drugs) was often left out. Answers needed to consider both systolic and diastolic function. An excellent answer included physiological phenomena such as the Treppe effect, Anrep effect and baroreceptor and chemoreceptor reflexes. Mention of normal conduction and pacing as well as blood supply limited by diastole scored additional marks.