Arterial pulse and venous pulse
Arterial Pulse and Venous Pulse
Formation, transmission, examination, pulse tracing, applied physiology and jugular venous pulse.
1 Arterial Pulse
Definition and Formation of Arterial Pulse
During contraction of left ventricle, blood is ejected forcefully into aorta.
It causes distension of aorta and rise in pressure.
So, a pressure wave is produced on the elastic wall of aorta.
This wave travels rapidly from the heart towards periphery.
It can be felt after a brief interval, at any superficial peripheral artery like radial artery at wrist.
Pulse Rate vs Heart Rate
Pulse rate is the accurate measure of heart rate.
Both are similar in all conditions except pulsus deficit.
2 Transmission of Arterial Pulse
Formation and transmission of pulse wave depends upon elasticity of blood vessels.
When walls of arteries are more distensible, the pressure rise is less and transmission of pulse is less.
When arterial wall loses its elasticity and becomes rigid as in elders, the pressure rise is more and transmission of pulse is also more.
Pulse is not transmitted to capillaries because capillaries do not have elastic tissues.
Velocity of Transmission of Pulse
Average velocity at which the pulse wave is transmitted varies between 7 and 9 m/sec.
Pulse wave travels faster than blood flow.
Maximum velocity of blood flow in the body, in larger arteries, is only 50 cm/sec.
3 Arterial Pulse Tracing
Arterial pulse is recorded by using a polygraph.
Pulse is recorded in radial artery or femoral artery as the typical peripheral pulse.
Peripheral pulse tracing has three main features.
1. Anacrotic Limb
Anacrotic limb or ascending limb is due to the rise in pressure during systole.
2. Catacrotic Limb
Catacrotic limb or descending limb is due to the fall in pressure during diastole.
3. Catacrotic Notch
In the upper part of catacrotic limb of pulse tracing, a small notch appears.
This notch is called catacrotic notch or incisura.
Catacrotic notch is produced by backflow of blood during closure of semilunar valves at the beginning of diastolic period, which produces slight increase in the pressure.
4. Pre- and Post-catacrotic Waves
The wave appearing before the notch is called precatacrotic wave.
Wave appearing after the notch is called postcatacrotic wave.
4 Pulse Points
Usually, pulse is palpated on the radial artery because it is easily approachable and placed superficially.
However, arterial pulse can be felt in different areas on the body.
These areas are called pulse points and the area of palpation is given below.
| Pulse Point | Area of Palpation |
|---|---|
| 1. Temporal pulse | Over the temple, in front of ear on superficial temporal artery |
| 2. Facial pulse | On facial artery at the angle of jaw |
| 3. Carotid pulse | On the neck along anterior border of sternocleidomastoid muscle on common carotid artery |
| 4. Axillary pulse | In axilla on axillary artery |
| 5. Brachial pulse | In cubital fossa along medial border of biceps muscle on brachial artery |
| 6. Radial pulse | Over the thumb side of wrist between tendons of brachioradialis and flexor carpi radialis muscles on radial artery |
| 7. Ulnar pulse | Over the little finger side of wrist on ulnar artery |
| 8. Femoral pulse | In the groin on femoral artery |
| 9. Popliteal pulse | Behind knee, in the popliteal fossa on popliteal artery |
| 10. Dorsalis pedis pulse | Over the dorsum of foot on dorsalis pedis artery |
| 11. Tibialis pulse | Over the back of the ankle behind medial malleolus on posterior tibial artery |
5 Examination of Radial Pulse
Pulse represents the heartbeat.
By examining pulse, important information regarding cardiac function such as rate of contraction, rhythmicity, etc., can be obtained.
In addition, an experienced person can determine mean arterial pressure by feeling the hardness of pulse and its amplitude.
Method of Examining Radial Pulse
Subject is made to sit comfortably with forearm placed in the mid-or semi-prone position, with wrist slightly flexed.
The observer must stand by the right side of subject.
Tips of middle three fingers (index finger, middle finger and ring finger) of the observer are placed over radial artery of the subject at wrist below the base of thumb.
Light pressure is applied by the fingers until the pulse is felt.
If necessary, fingers are moved around till the pulse is felt.
Index finger is used to occlude blood flow from radial artery.
Ring finger is used to occlude retrograde flow of blood from ulnar artery through palmar arch.
Middle finger is used to assess the pulse.
Pulse Rate at Different Ages
| Age | Pulse Rate (per min) |
|---|---|
| In fetus | 150 to 180 |
| At birth | 130 to 140 |
| At 10 years of age | 90 |
| After puberty | 72 |
Observations During Examination of Pulse
- Rate
- Rhythm
- Character
- Volume
- Condition of blood vessel wall
- Delayed pulse
1. Rate
Pulse rate is the number of pulses per minute.
It must be counted at least for 30 seconds.
Pulse rate in adults is 72/min.
Pulse rate is different at different ages.
Variations of Pulse Rate
Conditions When Pulse Rate Increases
- Exercise
- Pregnancy
- Emotional conditions
- Fever
- Anemia
- Hypersecretion of catecholamines
- Hyperthyroidism
Conditions When Pulse Rate Decreases
- Sleep
- Hypothermia
- Hypothyroidism
- Incomplete heart block
2. Rhythm
Rhythm is the regularity of pulse.
Under normal conditions, the pulse appears at regular intervals.
Rhythm of the pulse becomes irregular in some pathological conditions such as atrial fibrillation.
Irregular rhythm of pulse is of two types:
- Regularly irregular
- Irregularly irregular
3. Character
Character of pulse is observed while examining the pulse.
It denotes the tension on vessel wall produced by the waves of pulse.
4. Volume
Volume is the determination of movement of the vessel wall produced by transmission of pulse wave.
It is also a measure of pulse pressure.
It depends upon condition of the blood vessel.
5. Condition of Wall of Blood Vessel
Condition of wall of the blood vessel is assessed by feeling and rolling the radial artery against the underlying bones.
Normally, wall of the vessel is not palpable in children and young adults.
However, in elders wall of the vessel becomes rigid and palpable.
In abnormal conditions like arteriosclerosis, it is felt as a hard rope.
6. Delayed Pulse
Sometimes the arrival of pulse in certain peripheral arteries is delayed.
It is an important feature to be noted because it is useful in diagnosis of certain diseases.
For example, while palpating radial pulse and femoral pulse simultaneously, there is a short delay in the arrival of femoral pulse wave.
It is called femoral delay, radial-femoral delay or radiofemoral delay.
6 Applied Physiology: Abnormal Arterial Pulse
1. Pulsus Deficit
Pulsus deficit is an abnormal condition in which pulse rate is less than the heart rate.
Pulsus deficit occurs during atrial fibrillation.
Atrial fibrillation is the type of arrhythmia (irregular heartbeat) characterized by rapid and irregular atrial contractions at the rate of 300 to 400 beats per minute.
2. Pulsus Alternans
Pulsus alternans is an abnormal condition characterized by alternation of strong and weak pulse.
It is commonly seen in severe myocardial diseases.
3. Anacrotic Pulse
Anacrotic pulse is an abnormal pulse, characterized by slow ascending limb which has a notch called anacrotic notch.
It is produced in aortic stenosis (narrowing).
4. Thready Pulse
Thready or weak pulse is the abnormally weak and feeble pulse because of its low volume.
It is hardly felt at the arteries.
It usually occurs during severe hemorrhage or severe chills.
5. Pulsus Paradoxus
Pulsus paradoxus is a condition characterized by weak pulse with marked decrease in volume during inspiration caused by fall in systolic blood pressure by 10 mm Hg.
The pulse becomes normal or stronger with increase in volume during expiration.
It occurs in many cardiac diseases and respiratory diseases.
6. Water Hammer Pulse
Water hammer pulse or collapsing pulse is an abnormal pulse, characterized by a rapid upstroke and an equally rapid downstroke.
In other words, it is a bounding forceful pulse that quickly increases in volume and subsequently decreases in volume resulting in collapse.
It is seen in patent ductus arteriosus and aortic regurgitation.
7. Abnormal Pulse in Patent Ductus Arteriosus
Pulse during patent ductus arteriosus is a strong hammer pulse.
Patent ductus arteriosus is the persistence of the ductus arteriosus.
8. Abnormal Pulse in Aortic Regurgitation
Pulse during aortic regurgitation is also a strong water hammer pulse.
Aortic regurgitation is the backflow of blood from aorta into left ventricle.
It is due to incompetence of semilunar valve in aorta.
7 Venous Pulse
Definition and Importance of Venous Pulse
Venous pulse is observed only in larger veins near the heart such as jugular vein.
Evaluation of the venous pulse is an integral part of the physical examination because it reflects right atrial pressure and hemodynamic events in right atrium.
Significance of Venous Pulse Recording
- Venous pulse recording is used to determine rate of atrial contraction, just as the record of arterial pulse is used to determine rate of ventricular contraction.
- Many phases of cardiac cycle can be recognized by venous pulse tracing.
- It is the simple and accurate method to measure duration of different phases in diastole.
- It also represents the atrial pressure changes taking place during cardiac cycle.
8 Examination of Venous Pulse
Inspection of jugular vein pulsations is routinely done in bedside examination of neck veins.
It provides valuable information about cardiac function.
To observe the pulsation of internal jugular vein, head of the subject is tilted at 45°.
However, in patients with increased venous pressure, the head should be tilted as much as 90°.
Pulsation of jugular vein can be noticed when light is passed across the skin overlying internal jugular vein with neck muscles.
Simultaneous palpation of the left carotid artery helps the examiner confirm venous pulsations.
9 Jugular Venous Pulse Tracing
Recording of jugular venous pulse is also called phlebogram.
It is similar to intra-atrial pressure curve.
Phlebogram has three positive waves and three negative waves.
‘a’ Wave
It is the first positive wave.
It is due to rise in atrial pressure during atrial systole.
It precedes ventricular systole.
‘x’ Wave
‘x’ wave is a negative wave due to fall in atrial pressure.
It coincides with atrial diastole and beginning of ventricular systole.
‘c’ Wave
This positive wave is due to rise in atrial pressure during isometric contraction period.
During this period, atrioventricular valves bulge into atria and increase the pressure in atria slightly.
Earlier, it was thought that this wave was due to transmission of pulse from this carotid artery.
Hence, it was called ‘c’ wave.
‘x₁’ Wave
This negative wave is due to fall in atrial pressure during ejection period.
During ejection period, the atrioventricular valve is pulled towards ventricles causing distention of atria.
So, the atrial pressure falls.
‘v’ Wave
‘v’ wave is a positive wave due to rise in atrial pressure.
Pressure increases because of filling of atria (venous return).
It is obtained during isometric relaxation period or during atrial diastole.
‘y’ Wave
This negative wave denotes fall in atrial pressure due to opening of atrioventricular valve and emptying of blood into ventricle.
It appears during rapid and slow filling periods.
‘y’ wave is followed by ‘a’ wave and the cycle is repeated.
10 Applied Physiology: Abnormal Venous Pulse
1. Elevated Jugular Venous Pulse
Elevated jugular venous pulse indicates the rise in right ventricular pressure.
Conditions When Jugular Venous Pulse is Elevated
- Bradycardia
- Pericardial effusion
- Constrictive pericarditis
- Tricuspid stenosis
- Pulmonary hypertension
2. Kussmaul’s Sign
Kussmaul’s sign is the increase in venous distention and venous pressure.
Normally, it occurs during inspiration.