Feline Pericardial Effusion Study Guide

Overview and Clinical Importance

Pericardial effusion (PE) refers to the abnormal accumulation of fluid within the pericardial sac surrounding the heart. While this condition is relatively uncommon in cats (reported prevalence of 1-2.3% in necropsy studies), it carries significant clinical importance because it can lead to life-threatening cardiac tamponade. Understanding the unique aspects of feline pericardial effusion is essential for NAVLE success, as the etiology, presentation, and management differ substantially from canine patients.

Unlike dogs, where neoplasia (particularly hemangiosarcoma) is the most common cause, feline pericardial effusion is most frequently associated with congestive heart failure secondary to cardiomyopathy, particularly hypertrophic cardiomyopathy (HCM). In cats with CHF, mild pericardial effusion is present in approximately 46-49% of cases, though it is often an incidental finding that rarely causes cardiac tamponade.

Pericardial Anatomy and Physiology

The pericardium is a thin, translucent membrane that surrounds the heart and attaches at the heart base. It consists of two layers: