92
CARDIOVASCULAR PHYSIOLOGY CONCEPTS
0
10
20
A
LVEDP (mmHg)
B
LV Volume (ml)
CASE 4-3
Reduced ventricular filling time caused by
tachycardia leads to a decrease in EDV and
SV This preload change alone, however, will
not alter ESV The addition of a fall in arterial
pressure decreases afterload on the ventricle,
which independently increases stroke volume
and reduces ESV This can lead to a further
decrease in EDV The net effect of these two
conditions will be a large reduction in EDV
coupled with a small reduction in ESV, and
large fall in stroke volume. Because of the
hypotension (both systolic and diastolic), the
ejection phase of the pressure-volume loop
starts at a lower pressure, and the peak ven-
tricular systolic pressure is also reduced.
0
80
160
LV Volume (ml)
SUGGESTED RESOURCES
Braunwald E, Ross J, Sonnenblick EH. Mechanisms of
Contraction of the Normal and Failing Heart. 2nd
Ed. Boston: Little, Brown & Co., 1976.
Covell JW, Ross J. Systolic and diastolic function
(mechanics) of the intact heart. In: Page E, Fozzard HA,
Solaro RJ, eds. Handbook of Physiology, vol. 1. Bethesda:
American Physiological Society, 2002; 741-785.
Fuchs F, Smith SH. Calcium, cross-bridges, and the
Frank-Starling relationship. News Physiol Sci
2001;16:5-10.
Katz AM. Physiology of the Heart. 4th Ed. Philadelphia:
Lippincott Williams & Wilkins, 2006.
Lilly LS. Pathophysiology of Heart Disease. 5 th Ed.
Philadelphia: Lippincott Williams & Wilkins, 2011.
Opie LH. The Heart: Physiology from Cell to
Circulation. 4th Ed. Philadelphia: Lippincott
Williams & Wilkins, 2004.
Sagawa K, Maughan L, Suga H, Sunagawa K. Cardiac
Contraction and the Pressure-Volume Relationship.
New York: Oxford University Press, 1988.
Solaro, RJ. Integration of Myocyte Response to Ca2+
with
Cardiac Pump Regulation and Pump Dynamics. Am.
J. Physiol. 1999;277(Adv. Physiol. Educ. 22):
S155-S163.
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