Characteristics & Patterns of PULSE

Characteristics of Pulse

A pulse is generated because of the pressure waves caused by the pumping action of the heart.

It is the indirect measure of heartbeat and activity of the heart. The normal pulse has a small anacrotic wave on the upstroke which is not felt. This is followed by a big tidal or percussion wave which is felt by the palpating finger.

 =>    Rate

The rate is measured as beats per minute and is calculated by counting the beats for full one minute or counting for half a minute and then multiplying by two. If the rhythm is irregular, the pulse should be counted for a full one minute. The pulse rate can be used to check overall heart health and fitness level. Generally lower is better, but bradycardias can be dangerous. Symptoms of a dangerously slow heartbeat include weakness, loss of energy and fainting.

Mostly, the pulse rate and heart rate are equal but in case of premature beats or atrial fibrillations, the heart rate may be more than the pulse rate. The difference is called the pulse-rate deficit. In adults, the normal pulse appears at regular intervals and has a rate between 60-100 per min. There may be a mild variation in the rate between the two phases of respiration which is called sinus arrhythmia.

newborn (0–3 months old)	infants (3 – 6 months)	infants (6 – 12 months)	children (1 – 10 years)	children over 10 years & adults, including seniors	well-trained adult athletes
99-149	89–119	79-119	69–129	59–99	39–59

 =>    Rhythm

The normal rhythm is regular which indicates that the interval between two beats is always equal. An irregular pulse may be due to sinus arrhythmia, ectopic beats, atrial fibrillation, paroxysmal atrial tachycardia, atrial flutter, partial heart block etc. Intermittent dropping out of beats at pulse is called "intermittent pulse". Examples of regular intermittent (regularly irregular) pulse include pulsus bigeminus, second-degree atrioventricular block. An example of irregular intermittent (irregularly irregular) pulse is atrial fibrillation.

 =>    Force

Pulse force is the force or strength of the pulse felt when palpating. Also known as compressibility of pulse, it is a rough measure of systolic blood pressure. The force provides an idea of how hard the heart has to work to pump blood out of the heart and through the circulatory system.

The force is recorded using a scale

  -    3+ Full, bounding

  -    2+ Normal/strong

  -    1+ Weak, diminished, thready

  -    0 Absent/non-palpable

A 1+ force may reflect a decreased stroke volume [ can be seen in heart failure, heat exhaustion, or hemorrhagic shock, etc]. A 3+ force may reflect an increased stroke volume and is seen with exercise, stress, fluid overload, and high blood pressure.

 =>    Tension

Tension corresponds to diastolic blood pressure. A low tension pulse (pulsus mollis), the vessel is soft or impalpable between beats. In high tension pulse (pulsus durus), vessels feel rigid even between pulse beats.

 =>    Volume

The degree of expansion displayed by artery during diastolic and systolic state is called volume. It is also known as amplitude, expansion or size of pulse.

·   Hypokinetic pulse

A weak pulse signifies narrow pulse pressure. It may be due to low cardiac output (as seen in shock, congestive cardiac failure), hypovolemia, valvular heart disease (such as aortic outflow tract obstruction, mitral stenosis, aortic arch syndrome) etc.

·   Hyperkinetic pulse

A bounding pulse signifies high pulse pressure. It may be due to low peripheral resistance (as seen in fever, anemia, thyrotoxicosis, hyperkinetic heart syndrome [de], A-V fistula, Paget's disease, beriberi, liver cirrhosis), increased cardiac output, increased stroke volume (as seen in anxiety, exercise, complete heart block, aortic regurgitation), decreased distensibility of arterial system (as seen in atherosclerosis, hypertension and coarctation of aorta).

The strength of the pulse can also be reported:

 -    0 = Absent

 -    1 = Barely palpable

 -    2 = Easily palpable

 -    3 = Full

 -    4 = Aneurysmal or bounding pulse

 =>    Form

A form or contour of a pulse is palpatiory estimation of arteriogram. A quickly rising and quickly falling pulse (pulsus celer) is seen in aortic regurgitation. A slow rising and slowly falling pulse (pulsus tardus) is seen in aortic stenosis.

 =>    Pulse Equality

Comparing pulses and different places gives valuable clinical information.

A discrepant or unequal pulse between left and right radial artery is observed in anomalous or aberrant course of artery, coarctation of aorta, aortitis, dissecting aneurysm, peripheral embolism etc. An unequal pulse between upper and lower extremities is seen in coarctation to aorta, aortitis, block at bifurcation of aorta, dissection of aorta, iatrogenic trauma and arteriosclerotic obstruction.

 =>    Condition of Arterial Wall

A normal artery is not palpable after flattening by digital pressure. A thick radial artery which is palpable 7.5–10 cm up the forearm is suggestive of arteriosclerosis.

Patterns of Pulse

Several pulse patterns can be of clinically significance. These include:

  -    Dicrotic pulse

Dicrotic pulse is characterized by two beats per cardiac cycle, one systolic and the other diastolic. Physiologically, the dicrotic wave is the result of reflected waves from the lower extremities and aorta. Conditions associated with low cardiac output and high systemic vascular resistance can produce a dicrotic pulse.

  -    Pulsus Alternans

Pulsus alternans is characterized by a strong and weak beat occurring alternately, probably due to alternate rather than regular contraction of the muscle fibers of the left ventricle. Causes are left ventricular failure, toxic myocarditis, paroxysmal tachycardias. It may occur for several beats following a premature beat.

It is an ominous medical sign that indicates progressive systolic heart failure. To trained fingertips, the examiner notes a pattern of a strong pulse followed by a weak pulse over and over again. This pulse signals a flagging effort of the heart to sustain itself in systole.

  -    Pulsus Bigeminus

Pulsus bigeminus is the coupling of the waves in a pair, followed by a pause. It is seen in alternate premature beats, A.V. block, and sinoatrial block with ventricular escape. It indicates a pair of hoofbeats within each heartbeat. Concurrent auscultation of the heart may reveal a gallop rhythm of the native heartbeat.

  -    Pulsus Bisferiens

Pulsus bisferiens is a rapidly rising, twice beating pulse where both the waves are felt during systole. It is characterized by two beats per cardiac cycle, both systolic, unlike the dicrotic pulse. It's an unusual physical finding typically seen in patients with aortic valve diseases if the aortic valve does not normally open and close. Trained fingertips will observe two pulses to each heartbeat instead of one.

  -    Pulsus Parvus ET Tardus

Pulsus Parvus ET Tardus is a slow rising pulse like the anacrotic pulse but the anacrotic wave is not felt. It is seen in aortic stenosis. It is caused by a stiffened aortic valve that makes it progressively harder to open, thus requiring increased generation of blood pressure in the left ventricle.

  -    Pulsus Paradoxus

Systolic blood pressure normally falls by 3-10 mm Hg during inspiration. This is because though there is increased venous return to the right side of the heart, there is relative pooling of the blood in the pulmonary vasculature as a result of lung expansion and more negative intrathoracic pressure during inspiration.

This decreases the venous return to the left atrium and ventricle and subsequently causes a fall in left ventricular output thereby decreasing the arterial pressure. When the drop is more than 10 mmHg, it is referred to as pulsus paradoxus. During inspiration, the pulse is erroneously called pulsus paradoxus although it is merely an exaggeration and not a reversal of the normal.

The paradox of this phenomenon is that in extreme cases the peripheral pulse can disappear on inspiration while paradoxically, heart sounds remain audible during the “missed beats”. A reverse pulsus paradoxus may occur in patients receiving continuous airway pressure on a mechanical ventilator. Pulsus paradoxus is seen in superior vena cava obstruction, lung conditions like asthma, emphysema or airway obstruction, cardiac conditions like pericardial effusion, constrictive pericarditis and severe congestive cardiac failure.

  -    Tachycardia

Tachycardia is an elevated resting heart rate. In general an electrocardiogram (ECG) is required to identify the type of tachycardia.

  -    Pulsatile

Pulsatile description of the pulse implies the intrinsic physiology of systole and diastole. Scientifically, systole and diastole are forces that expand and contract the pulmonary and systemic circulations.

  -    Anacrotic

Anacrotic pulse is a slow rising, twice beating pulse where both the waves are felt during systole. The waves that are felt are the anacrotic wave and the tidal wave. It is best felt in the carotid artery in aortic stenosis.

  -    Thready Pulse

Thready pulse rate is rapid and the pulse wave is small and disappears quickly. This is seen in shock especially cardiogenic.

  -    Waterhammer Pulse

Waterhammer pulse is a large bounding pulse associated with an increased stroke volume of the left ventricle and a decrease in the peripheral resistance, leading to wide pulse pressure. The pulse strikes the palpating finger with a rapid, forceful jerk and quickly disappears. It is best felt in the radial artery with the patient’s arm elevated. It is caused by the artery suddenly emptying because some of the blood flows back from the aorta into the ventricle.