Narrow pulse pressure: signs, symptoms, and causes

Pulse pressure is calculated as systolic blood pressure minus diastolic blood pressure. The normal value is 40 mmHg. Each variation in vascular blood pressure has distinct clinical significance. The determination of pulse pressure is very complicated. The determining factors are arterial resistance, arterial properties, and stroke volume/cardiac output

Flowchart of Mechanism of Narrow pulse pressure

Description

Blood pressure less than 20 mmHg.

Cause

Popular

Heart failure.

Aortic stenosis.

Hypovolemic shock.

Rarely

Hypertrophic cardiomyopathy.

Mitral valve stenosis.

Mechanism

It must be remembered that systolic pressure is the greatest pressure during systole, while diastolic pressure is the smallest pressure in the arteries during diastole. Decreased cardiac output and increased systemic resistance are the most common pathways to narrow pulse pressure.

In practice, this means that any condition that reduces cardiac output (systolic blood pressure) with constant arterial resistance will cause narrow pulse pressure

Heart failure

In heart failure, low stroke volume leads to increased sympathetic reflexes and increased vascular resistance to maintain blood pressure and help venous return to the heart. Thus, systolic blood pressure is reduced (due to decreased cardiac output) and diastolic pressure is maintained (due to increased vascular resistance), creating narrow pulse pressure

Shock

In the early stages of hypovolemic shock, catecholamine levels are high as the body tries to increase peripheral resistance to maintain venous blood return to the heart. Increased peripheral resistance increases diastolic blood pressure, and as a result, blood pressure constriction.

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