Pulse, Abnormal

Pulse is the rhythmic expansion of the arterial wall that is dependent on myocardial contractions and elasticity of the wall. Pulse is examined using palpation and auscultation of superficial arteries. The following arteries are palpated (bilaterally) in adults: common carotid, radial, brachial, femoral, popliteal, dorsalis pedis, and tibialis posterior. Examination of pulse includes assessment of its rate (rapid, slow), rhythm (regular, irregular), amplitude (can be equated with pulse pressure; high amplitude, low amplitude), and duration of the systolic wave (quick, delayed).

Causes of abnormal pulse:

1) Low-amplitude delayed pulse (pulsus parvus et tardus): Aortic stenosis.

2) Thready pulse (quick, very fine): Shock, rarely fever or cardiac tamponade.

3) Hypokinetic pulse: Reduced left ventricular stroke volume (heart failure, impaired left ventricular outflow), increased peripheral vascular resistance.

4) Quick high-amplitude pulse (pulsus magnus et celer): Aortic regurgitation, patent ductus arteriosus, hyperdynamic circulation.

5) Hyperkinetic pulse: Aortic regurgitation, patent ductus arteriosus, hyperdynamic circulation, hypertrophic cardiomyopathy with obstruction of the left ventricular outflow tract (LVOT), mitral regurgitation.

6) Bisferious pulse (pulsus bisferiens; 2 strong systolic peaks): Hypertrophic cardiomyopathy with obstruction of the LVOT, combination of aortic regurgitation and stenosis.

7) Dicrotic pulse (one peak during systole and another at the beginning of diastole): Cardiac tamponade, severe heart failure, hypovolemic shock; it may rarely occur in healthy young individuals.

8) Paradoxical pulse (pulsus paradoxus): Normally blood pressure declines during inhalation (increase in blood inflow and volume of the right atrium with decreased compliance of the left atrium and subsequent decreased blood flow to the left ventricle); such decreases are <10 mm Hg. Pulsus paradoxus occurs as an exacerbation of this process and is seen during steady respiration: the pulse significantly decreases or disappears during inspiration and is accompanied by a decrease >10 mm Hg in systolic blood pressure. Pulsus paradoxus can be measured using a sphygmomanometer and is present when the first Korotkoff sound appears only during expiration. It can occur in patients with cardiac tamponade (majority of cases), constrictive pericarditis, massive pulmonary embolism, shock, asthma, and severe chronic obstructive pulmonary disease (COPD) (due to large fluctuations in the intrathoracic pressures).

9) Alternating pulse (pulsus alternans; alternating high- and low-amplitude pulse waves): Left ventricular failure.

10) Bigeminal pulse (a ventricular premature beat occurs after each normal systole): Ventricular premature beats in a patient with sinus rhythm, Mobitz type I (Wenckebach) second-degree atrioventricular block with 3:2 conduction and a nonconducted supraventricular premature beat appearing after every other sinus beat.

11) Pulse deficit (difference between the number of heart beats and the number of palpated pulses per minute): Rapid atrial fibrillation, numerous ventricular premature beats.

12) Differences in pulse amplitudes on symmetric arteries: Arterial stenosis (most frequently due to atherosclerosis), aortic dissection, aortic aneurysm, Takayasu disease, coarctation of the aorta, supravalvular aortic stenosis.