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. On the following downstroke there is a notch (dicrotic notch) followed by a wave (dicrotic wave) both of which are not normally palpable.

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.

Anacrotic Pulse

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 carotids in aortic stenosis.

Pulsus Bisferiens

Pulsus bisferiens is a rapid rising, twice beating pulse where both the waves are felt during systole. Here the percussion wave is felt first followed by a small wave. It is seen in:

1. Idiopathic hypertrophic subaortic stenosis: Here initially there is no obstruction to the outflow and about 80 percent of the stroke volume is ejected in the early part of systole. The obstruction occurs in midsystole when aortic valve approximates the hypertrophied septum. Hence, there is a dip, as suddenly the flow ceases, followed by a secondary rise as the L.V. overcomes the obstruction.
2. Severe A.I. with mild A.S.: The volume flow is initially increased due to severe. A.I. mild A.S. causes an extra high velocity jet to be shot out resulting in the second wave.

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.

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 fibres of the left ventricle.

Causes

1. Left ventricular failure
2. Toxic myocarditis
3. Paroxysmal tachycardias
4. For several beats following a premature beat

Pulsus Paradoxus

Pulsus paradoxus normally systolic blood pressure falls by 3-10 mm. 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 decreasing the arterial pressure. When the systolic blood pressure falls more than 10 mm. Hg. During inspiration the pulse is erroneously called pulsus paradoxus although it merely is 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.

Causes

1. Superior vena cava obstruction
2. Lung conditions

Asthma

Emphysema

Airway obstruction

3. Cardiac

Pericardial effusion

Constrictive pericarditis

• Severe congestive cardiac failure

Pulsus Bigeminus is coupling of the pulse waves in pair, followed by a pause.

Causes

1. Alternate premature beats
2. A.V. block, every third sinus impulse being blocked
3. Sinoatrial block with ventricular escape

Thready Pulse

The 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 increased stroke volume of the left ventricle and decrease in the peripheral resistance, leading to a 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.

Causes

Physiological

1. Fever
2. Alcohol
3. Pregnancy

High output states

1. Anemia
2. Beriberi
3. Cor pulmonale
4. Cirrhosis of liver
5. Paget’s disease
6. Arteriovenous fistula
7. Thyrotoxicosis

Cardiac lesions

1. Aortic regurgitation
2. Rupture of sinus of Valsalva into the heart chambers
3. Patent ductus arteriosus
4. Aortopulmonary window
5. Bradycardia
6. Systolic hypertension