What Causes a Narrow Pulse Pressure?

Small pulse pressure—the difference between systolic and diastolic blood pressure—is a clinically meaningful finding that often signals underlying cardiovascular pathology. A narrow pulse pressure, typically defined as less than 25 mmHg, reflects reduced stroke volume or impaired left ventricular ejection, rather than isolated arterial stiffness or peripheral resistance changes.

One of the most common causes is severe aortic stenosis, where calcified or fibrotic aortic valve leaflets restrict forward flow during systole. This results in diminished cardiac output and a blunted systolic pressure rise, while diastolic pressure remains relatively preserved—leading to a compressed pulse pressure. Similarly, advanced heart failure with reduced ejection fraction (HFrEF) can produce low stroke volume and elevated systemic vascular resistance, further narrowing the pressure gradient.

Other important etiologies include hypovolemic shock, particularly in acute settings such as major hemorrhage or sepsis-induced distributive shock with myocardial depression; severe cardiogenic shock post-myocardial infarction; and marked bradycardia due to high-grade atrioventricular block, which compromises ventricular filling time and stroke volume. In some cases, chronic severe mitral regurgitation may also contribute by reducing effective forward stroke volume despite preserved left ventricular contractility.

Clinically, a narrow pulse pressure warrants prompt evaluation—including physical examination for signs like delayed carotid upstroke, paradoxical splitting of S2, or a soft or absent S1—and targeted diagnostics such as echocardiography to assess valvular anatomy, ventricular function, and hemodynamic parameters. It should never be interpreted in isolation but integrated with clinical context, vital signs, and laboratory findings to guide timely intervention.