Editorial: Pericardial mass: Unusual interference with the right ventricular function

Right ventricular (RV) diastolic dysfunction is an important indicator for the assessment of heart failure. Abnormalities in RV diastolic function underlie many pathologies. However, the underlying mechanisms remain poorly described, because the term is used to describe many variants in diastolic pathophysiology and function. Since the right ventricle is coupled to the pulmonary circulation with a lower intracavity pressure and had a thin wall, the right ventricle is more compliant than the left ventricle. Thus, the RV volume overload as well as pressure overload may lead to RV distension, which would be restricted by the pericardium. Thus, RV diastolic dysfunction can be caused by any combination of abnormalities in the physiological properties of RV muscle including relaxation as well as compliance, ventricular interdependence [1], and pericardial constraint. RV dysfunction due to the worsening of RV muscle relaxation or RV muscle compliance may occur in the conditions such as RV infarction, restrictive cardiomyopathy, and arrhythmogenic RV cardiomyopathy. However, it is rare that the main cause of RV diastolic dysfunction is due to the impairment of RV muscle itself. Since the right ventricle is surrounded by the pericardium and the RV pressure is much lower compared with left ventricular (LV) pressure, the intrapericardial pressure would practically affect the RV geometrical changes and RV filling. The pericardium has a restrictive effect on the dilated and damaged right ventricle, while the right ventricle could be remarkably distended in the absence of the pericardium [2]. Thus, the pericardium is essential to regulate the RV hemodynamics. The muscle fibers of the RV free wall are orientated transversely and squeeze the blood within the ventricle in a circumferential compression motion [3]. The connections between the muscle fibers of the right ventricle and left ventricle tether the ventricles together through the interventricular septum. The concept of ventricular interdependence is that the size, shape, and compliance of one ventricle can directly affect the size, shape, and hemodynamics of the contralateral ventricle through septal wall reconfiguration, along with the pericardial constraint.