Pulse
Definition
Cardiac
Output is the volume of blood pumped into the arteries by the heart and
equals the result of the stroke volume (SV) times the heart rate (HR) per
minute
Peripheral Pulse/ Point of maximal impulse
Pulse located away from the heart (E.g.
Foot or wrist). The apical pulse is a central pulse; that is located at the
apex of the heart.
Physiology and Regulation
1. Electrical
impulses originating from the sinoartrial (SA) node travel through heart muscle
to stimulate cardiac contraction. Approximately 60 to 70 ml of blood enters the
aorta with each ventricular contraction (stroke volume). With each stroke
volume ejection, the walls of the aorta distend, creating a pulse wave that
travels rapidly toward the distal ends of the arteries.
2. The
pulse is the palpable bounding of the blood flow in the periphery artery. The
number of pulsing sensations occurring in I minute is the pulse rate.
3. The
volume of blood pumped by the heart during 1 minute is the cardiac output, the
product of HR and the stroke volume (S V) of the ventricle.
4. Mechanical,
neural and chemical factors regulate the strength of ventricular contraction
and its stroke volume. But when these factors are unable to alter stroke
volume, a change in HR
results in a change in cardiac output, which affects BP.
As HR increases, there is
less time for the heart to fill. As HR increases without a change in stroke
volume, BP decreases. As HR slows, filling time is increased and BP increases.
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