This study investigates the relationship between epicardial adipose tissue (EAT) and pericardial constraint in patients with heart failure with preserved ejection fraction (HfPEF). The authors hypothesized that increased EAT within the pericardial sac is associated with hemodynamic signs of pericardial constraint. They included 64 HfPEF patients who underwent invasive heart catheterization and echocardiography. Key findings include: - 73% of patients had a square root sign on the right ventricular pressure waveform, indicating pericardial constraint. - Patients with the square root sign had higher body mass index (BMI), EAT thickness, and right atrial pressure (RAP). - Women had more EAT than men, despite comparable BMI. - Women with the square root sign had significantly higher EAT, RAP, and RAP/PCWP ratio compared to women without the sign. - Men did not show significant associations between EAT and pericardial constraint. The study suggests that obesity and increased EAT are associated with hemodynamic signs of pericardial constraint in HfPEF, particularly in women. Further research is needed to explore the pathophysiological and therapeutic implications of these findings.This study investigates the relationship between epicardial adipose tissue (EAT) and pericardial constraint in patients with heart failure with preserved ejection fraction (HfPEF). The authors hypothesized that increased EAT within the pericardial sac is associated with hemodynamic signs of pericardial constraint. They included 64 HfPEF patients who underwent invasive heart catheterization and echocardiography. Key findings include: - 73% of patients had a square root sign on the right ventricular pressure waveform, indicating pericardial constraint. - Patients with the square root sign had higher body mass index (BMI), EAT thickness, and right atrial pressure (RAP). - Women had more EAT than men, despite comparable BMI. - Women with the square root sign had significantly higher EAT, RAP, and RAP/PCWP ratio compared to women without the sign. - Men did not show significant associations between EAT and pericardial constraint. The study suggests that obesity and increased EAT are associated with hemodynamic signs of pericardial constraint in HfPEF, particularly in women. Further research is needed to explore the pathophysiological and therapeutic implications of these findings.