Kussmaul Sign

Kussmaul Sign is a physical finding related to the heart and veins in the neck. It occurs when the veins in the neck, called the jugular veins, become more swollen instead of less swollen during deep breathing in. Normally, these veins should collapse slightly when a person inhales deeply. This sign indicates a problem with the heart's ability to fill properly with blood, often due to stiffness or restriction of the heart muscle. It is commonly seen in conditions affecting the heart's right side, such as constrictive pericarditis or right heart failure. The presence of this sign helps doctors understand how well the heart is functioning and can guide further testing and treatment.

Kussmaul Sign is defined as a paradoxical increase in jugular venous pressure (JVP) during inspiration, reflecting impaired right ventricular filling. It is typically caused by conditions that restrict right heart expansion, such as constrictive pericarditis, restrictive cardiomyopathy, or severe right ventricular failure. Normally, inspiration decreases intrathoracic pressure, enhancing venous return and lowering JVP, but in these pathologies, the rigid pericardium or dysfunctional myocardium prevents right ventricular compliance, causing venous pressure to rise instead. This sign is clinically significant as it helps differentiate constrictive pericarditis from other causes of heart failure and guides management. It is a key physical exam finding indicating elevated right atrial pressure and impaired diastolic filling.