12.11.29 Pulses

Unequal or Delayed

• • Obstructive arterial diseases

    • Most commonly atherosclerosis

  • Aortic dissection

  • Aortic aneurysm

  • Takayasu's disease

  • Supravalvular aortic stenosis

    • Right carotid, brachial, and radial pulses are larger in amplitude and volume than those on the left side

    • Due to preferential streaming of the jet toward the innominate artery

  • Coarctation of the aorta

    • Delay in onset of femoral pulse

Pulsus alternans

• • Definition

    • Variation in pulse amplitude occurring with alternate beats due to changing systolic pressure

  • Aetiology

    • Left ventricular failure

  • Other rare causes

    • Hypertrophic cardiomyopathy and a significant rest or provocable outflow gradient

    • Cardiac tamponade

    • Severe aortic regurgitation

  • Apparent pulsus alternans

    • Due to bigeminal rhythm

  • Mechanism unclear

    • Alternating preload (Frank-Starling mechanism) and incomplete relaxation have been proposed

    • Changes in afterload, which is lower after preceding the strong beat, may also contribute

Pulsus paradoxus

• • Definition

    • Inspiratory decrease in arterial pressure exceeding 20 mmHg

  • Aetiology

    • Cardiac tamponade

    • COPD

    • Hypovolemic shock

    • Constrictive pericarditis

    • Restrictive cardiomyopathy

  • Mechanism

    • Inspiratory decline of left ventricular stroke volume due to an increase in right ventricular end-diastolic volume and decreased left ventricular end-diastolic volume

Pulsus bisferiens

• • Definition

    • Two systolic peaks of the aortic pulse during left ventricular ejection separated by a midsystolic dip

  • Aetiology

    • Aortic regurgitation

    • Common in patients with combined aortic stenosis and aortic regurgitation

    • PDA or arteriovenous fistula

  • Mechanism

    • Unclear

    • Appears to be related to a large, rapidly ejected left ventricular stroke volume associated with increased left ventricular and aortic dp/dt

  • Pitfalls

    • Difficult to establish with certainty that the two peaks are occurring in systole

    • (One peak in systole and the other in diastole = Dicrotic pulse)

Dicrotic pulse

• • Definition

    • Accentuated diastolic dicrotic wave that follows the dicrotic notch

  • Aetiology

    • Severe heart failure

    • Hypovolemic shock

    • Cardiac tamponade

    • Conditions associated with a decreased stroke volume and elevated systemic vascular resistance

  • Mechanism

    • Tends to occur when the dicrotic notch is low (decreased systemic arterial pressure and vascular resistance)

  • Pitfall

    • Frequently confused with pulsus bisferiens at the bedside

    • It is almost impossible to distinguish between these two types of pulse configurations without a pulse recording

Corrigan pulse

• • Definition

    • Abrupt, very rapid upstroke of the peripheral pulse (percussion wave), followed by rapid collapse

  • Aetiology

    • Chronic, hemodynamically significant aortic regurgitation

  • Mechanism

    • Rapid ejection of a large left ventricular stroke volume into a low resistance arterial system

Anacrotic pulse

• • Definition

    • Interruption of the upstroke of the carotid pulse

  • Aetiology

    • Aortic stenosis

Pulsus tardus

• • Definition

    • Delayed upstroke of the ascending limb

  • Aetiology

    • Aortic stenosis

  • Mechanism

    • Prolonged left ventricular ejection time

Notes

• Dicrotic notch

  • Coresponds to aortic valve closure

  • Just as the ventricles enter into diastole, the brief reversal of flow from the aorta back into the left ventricle causes the aortic valves to shut

  • This results in the slight increase in aortic pressure caused by the elastic recoil of the semilunar valves and aorta