Which pulse height falls with inspiration?

Which pulse height falls with inspiration?

• A. Jugular
• B. Carotid
• C. Both
• D. Neither

Answer: (A)

During inspiration, intrathoracic pressure becomes more negative, which increases venous return to the right heart and lowers right atrial pressure. Because the jugular venous pulse reflects right atrial pressure, its height falls with inspiration. The carotid pulse, driven mainly by left ventricular ejection, is not normally affected in height by breathing, so it does not fall with inspiration. Only in certain pathologies (like pulsus paradoxus) would you see a noticeable inspiratory drop in arterial pulse height, but in normal physiology the jugular venous pulse is the one that diminishes with inspiration.

During inspiration, intrathoracic pressure becomes more negative, which increases venous return to the right heart and lowers right atrial pressure. Because the jugular venous pulse reflects right atrial pressure, its height falls with inspiration. The carotid pulse, driven mainly by left ventricular ejection, is not normally affected in height by breathing, so it does not fall with inspiration. Only in certain pathologies (like pulsus paradoxus) would you see a noticeable inspiratory drop in arterial pulse height, but in normal physiology the jugular venous pulse is the one that diminishes with inspiration.