Pulse

Pulse

Definition

The pulse is a wave of blood created by contraction of the left ventricle of the heart. Pulse wave represent the stoke volume output or the amount of blood that enters the arteries with each ventricular contraction

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.