What phenomenon is associated with cardiac tamponade during inspiration?

Pulsus paradoxus is a significant finding associated with cardiac tamponade, particularly noted during phases of respiration. This phenomenon refers to an exaggeration of the normal drop in blood pressure that occurs with inspiration, which can be more pronounced in the presence of cardiac tamponade.

During inspiration, negative intrathoracic pressure increases venous return to the right side of the heart, causing a shift in the interventricular septum towards the left ventricle. In a healthy heart, this slight change may result in a minor decrease in systolic blood pressure. However, in patients with cardiac tamponade, the pericardial fluid exerts pressure on the heart, compromising its ability to fill adequately, especially during diastole. As a result, the systolic blood pressure can drop significantly with inspiration, leading to a pulsus paradoxus, where the difference in systolic blood pressure between expiration and inspiration exceeds 10 mmHg.

This phenomenon is clinically significant as it indicates the severe hemodynamic compromise associated with cardiac tamponade and helps differentiate it from other causes of hypotension. Understanding pulsus paradoxus can assist healthcare professionals in diagnosing and managing patients with cardiac tamponade effectively.