Kussmaul’s Sign
Kussmaul’s Sign – Overview
🔹 Definition
Kussmaul’s sign is the paradoxical rise in jugular venous pressure (JVP) during inspiration, instead of the normal fall.
🔬Kussmaul’s Sign- Mechanism
- Normally, inspiration → negative intrathoracic pressure → increased venous return → fall in JVP.
- In Kussmaul’s sign, there is impaired right ventricular filling due to non-compliant or restricted right ventricle, so the venous return cannot be accommodated → JVP rises instead.
📌 Causes of Kussmaul’s Sign
Most Common:
- Constrictive pericarditis
Other Causes:
- Restrictive cardiomyopathy
- Right ventricular infarction
- Severe right heart failure
- Tricuspid stenosis
- Massive pulmonary embolism
- Cardiac tamponade (❌ usually absent, but occasionally seen in advanced cases)
🧾 Kussmaul’s Sign- Clinical Importance
- Indicates right-sided diastolic dysfunction
- Useful sign in differentiating cardiac tamponade (usually absent) from constrictive pericarditis (present)
🩺 Bedside Finding
- Inspect jugular venous pulse (JVP)
- Ask patient to take a deep breath → if JVP rises instead of falling, Kussmaul’s sign is present
📝 Key Differentiation Table
| Feature | Normal Inspiration | Kussmaul’s Sign |
|---|---|---|
| JVP change | Falls | Rises |
| Mechanism | Enhanced venous return handled by RV | RV can’t accommodate ↑ venous return |
| Typical Disease | Normal heart | Constrictive pericarditis, RCM, RV infarct, TS |
Summary of Kussmaul’s Sign
| Point | Key Fact |
|---|---|
| 1 | Kussmaul’s sign = rise in JVP during inspiration. |
| 2 | Normal physiology: JVP falls on inspiration due to ↑ venous return. |
| 3 | Occurs when RV cannot accommodate increased venous return. |
| 4 | Most classic cause = Constrictive pericarditis. |
| 5 | Also seen in restrictive cardiomyopathy. |
| 6 | Seen in right ventricular infarction. |
| 7 | Seen in tricuspid stenosis and severe RV failure. |
| 8 | Usually absent in cardiac tamponade (key differentiator). |
| 9 | But occasionally present in advanced tamponade. |
| 10 | Represents impaired diastolic filling of RV. |
| 11 | Best observed in jugular venous pulse during deep inspiration. |
| 12 | Sign of elevated right atrial pressure with non-compliance. |
| 13 | Indicates advanced right-sided heart dysfunction. |
| 14 | Helps distinguish between pericardial and myocardial disease. |
| 15 | May coexist with pericardial knock in constrictive pericarditis. |
| 16 | Differentiates constrictive pericarditis (present) from tamponade (absent). |
| 17 | Pathophysiology = ventricular interdependence & rigid pericardium. |
| 18 | Can be demonstrated with right heart catheterization. |
| 19 | Not to be confused with pulsus paradoxus (different mechanism). |
| 20 | Clinical pearl: Kussmaul’s sign = “Kusstrictive pericarditis”. |
💡 10 Short Q&A on Kussmaul’s Sign
Q1. What is Kussmaul’s sign?
Ans: Paradoxical rise in jugular venous pressure (JVP) during inspiration.
Q2. What is the normal JVP response to inspiration?
Ans: Normally, JVP falls during inspiration due to increased venous return to the right heart.
Q3. What is the most common cause of Kussmaul’s sign?
Ans: Constrictive pericarditis.
Q4. Name two myocardial causes of Kussmaul’s sign.
Ans: Restrictive cardiomyopathy and right ventricular infarction.
Q5. Is Kussmaul’s sign usually seen in cardiac tamponade?
Ans: No, it is usually absent (helps in differentiation from constrictive pericarditis).
Q6. What is the underlying mechanism of Kussmaul’s sign?
Ans: Impaired right ventricular filling due to a non-compliant pericardium or myocardium.
Q7. Which valvular disease may produce Kussmaul’s sign?
Ans: Tricuspid stenosis.
Q8. How can Kussmaul’s sign be detected clinically?
Ans: By observing the jugular venous pulse (JVP) rise with inspiration.
Q9. What hemodynamic feature corresponds to Kussmaul’s sign on right heart catheterization?
Ans: Elevated right atrial pressure that rises further during inspiration.
Q10. What is a simple memory aid for Kussmaul’s sign?
Ans: “Kusstrictive pericarditis” → Kussmaul’s sign is classically seen in constriction.
