Relate the surface electrocardiogram (ECG) to the events of the cardiac cycle (60% of marks). Briefly describe the mechanism of the effects of digoxin, and the mechanism of the effects of amiodarone, on the ECG (40% of marks)

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College Answer

Candidates were expected to provide sufficient detail in answers. Extra marks were
awarded for diagrams relating the ECG accurately to pressure events during the
cardiac cycle. Time intervals, units of measurement and clear labels were essential
for diagrams.
Mechanisms pertaining to ion flux and ion channels needed to be specifically
explained. Discussion of mechanisms needed to be accurate and relevant to the
effect on the ECG. For example, better answers noted that AV conduction was
depressed by Digoxin, predominantly due to an increase in Vagal tone
Syllabus: Cib2c C2c2b
Recommended sources: Principles of Physiology for the Anaesthetist, Power and
Kam, pages 107-110, Pharmacology and Physiology in Anaesthetic Practice,