Normal Waveform of the Arterial Pulse

Mechanism of Pulse Formation

Blood ejected into the aorta during systole generates a pressure wave that travels along the arterial wall at approximately 4 m/s in the aorta, 8 m/s in large arteries, and 16 m/s in small arteries. This wave expands the arterial wall as it passes, and that expansion is what we palpate as the pulse. The pressure wave velocity is far higher than actual blood flow velocity. As a result, the radial pulse at the wrist is felt about 0.1 seconds after the peak of systolic ejection into the aorta.

Ganong's Review of Medical Physiology, 26th Ed., p. 542

The Normal Arterial Pressure Waveform

The diagram below (from Miller's Anesthesia) shows the normal waveform alongside the ECG. Each numbered component is labeled:

Normal arterial blood pressure waveform showing systolic upstroke (1), systolic peak (2), systolic decline (3), dicrotic notch (4), diastolic runoff (5), and end-diastolic pressure (6)

FIG. 32.25 - Miller's Anesthesia, 10e. Normal arterial blood pressure waveform and its relation to the ECG R wave.

Components of the Normal Pulse Waveform

#	Component	Description
1	Systolic upstroke (Anacrotic limb)	Rapid rise in pressure as the left ventricle ejects blood into the aorta. The ascending limb is steep in normal individuals.
2	Systolic peak	The highest point of the waveform, corresponding to peak systolic pressure (~120 mmHg normally).
3	Systolic decline (Catacrotic limb)	Pressure falls as ejection slows and ventricular outflow decreases.
4	Dicrotic notch	A small notch/oscillation on the descending limb caused by vibrations when the aortic valve snaps shut (end of systole). It is visible on pressure recordings but not palpable at the wrist.
5	Diastolic runoff	Gradual decline in pressure as blood continues to flow into the peripheral circulation during diastole.
6	End-diastolic pressure	The lowest point of the waveform, corresponding to diastolic pressure (~70-80 mmHg normally).

Miller's Anesthesia, 10e, p. 4774

Key Features of the Normal Pulse on Palpation

A normal arterial pulse (shown leftmost in the chart below, compared with pathological patterns) has:

Arterial pulse waveform patterns showing Normal, HOCM, Severe Aortic Stenosis, Severe Aortic Regurgitation, and Hypokinetic/Shock

Fuster and Hurst's The Heart, 15th Ed. - Arterial pulse waveform patterns.

Sharp systolic upstroke - brisk, rapid rise
Narrow, rounded peak - single well-defined systolic peak (~100 mmHg)
Prominent dicrotic notch on the downstroke
Rapid downstroke back toward baseline
Sabiston Textbook of Surgery, 20e

Pulse Pressure and Wave Strength

The strength of the pulse depends on the pulse pressure (systolic - diastolic), not mean arterial pressure:

Weak/thready pulse: low stroke volume, as in shock
Strong/bounding pulse: high stroke volume (exercise, aortic regurgitation, histamine administration)
Corrigan/water-hammer pulse: seen in aortic regurgitation - very strong upstroke with rapid collapse

Distal Pulse Amplification

As the pressure wave travels from the aorta to peripheral arteries, the waveform changes:

Wider pulse pressure
Delayed systolic upstroke
Slurred, delayed dicrotic notch
More prominent diastolic wave

This is because retrograde reflected waves at the arteriolar level add to the antegrade wave, amplifying the peripheral waveform.

Miller's Anesthesia, 10e, p. 4775

Summary

Parameter	Normal Value
Systolic pressure	~120 mmHg
Diastolic pressure	~80 mmHg
Pulse pressure	~40 mmHg
Pulse wave velocity (aorta)	~4 m/s
Radial pulse delay from aorta	~0.1 sec
Dicrotic notch	Present (visible on recording, not palpable)

The normal pulse has a brisk upstroke, single systolic peak, and dicrotic notch - any deviation from this pattern points toward specific cardiac or vascular pathology.

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