Briefly describe the cardiovascular events that occur during ventricular diastole.
One possible way to answer this question is to offer a definition of the diastolic
period then to split the events up for description into mechanical events, ECG
events and electrical/ionic events.
Few candidates defined the diastolic period, and whilst many talked about
opening and closing of valves, there was generally a poor understanding of the
sequence of events whereby the left ventricle comes to be filled with blood. The
better answers included a description of the ionic events that occurred at the
various stages of diastole. Many answers lacked any reference to the ECG
events in diastole.
The major weakness in answers was again the failure to include sufficient
information to achieve a pass mark. This was probably as a result of the lack of a
systematic approach when answering a question of this nature.
Syllabus: C1b, 2d,e and C1c, 2e,f
Recommended sources: Textbook of Medical Physiology, Guyton & Hall, Chp 9 – 11
and Review of Medical Physiology, Ganong, Chp 31
Definition of diastole
Events during diastole:
Wiggers, Carl J. "Studies on the consecutive phases of the cardiac cycle: I. The duration of the consecutive phases of the cardiac cycle and the criteria for their precise determination." American Journal of Physiology-Legacy Content 56.3 (1921): 415-438.
Braunwald, Eugene, ALFRED P. FISHMAN, and AndrÉ Cournand. "Time relationship of dynamic events in the cardiac chambers, pulmonary artery and aorta in man." Circulation research 4.1 (1956): 100-107.
Luisada, Aldo A., and Donald M. MacCanon. "The phases of the cardiac cycle." American heart journal 83.5 (1972): 705-711.