Ventricle works as a converting organ of atrial blood flow: physiological significance of mean ventricular pressure.

The roles and characteristics of the ventricle were examined using mean ventricular pressure (MVP) in ventricular-vascular association. One hundred and two patients with congenital heart diseases who had undergone cardiac catheterization were studied. They were divided into five groups: Group 1, atrial septal defect without pulmonary hypertension (PH); Group 2, ventricular septal defect (VSD) without PH; Group 3, VSD with PH; Group 4, pulmonary valvular stenosis; and Group 5 as a control group. Then, we examined the relationships between mean pulmonary artery pressure (MPAP) and mean right ventricular pressure (MRVP), and also between mean systemic arterial pressure (MSAP) and mean left ventricular pressure (MLVP) among the five groups. Furthermore, we defined new indicators to express the ease of blood flow through each ventricle. They were referred to as a conductance of the right ventricle (CDR) and a conductance of the left ventricle (CDL), respectively. Then they were compared among the five groups. The values of MPAP/MRVP and MSAP/MLVP were kept constant to be about 1.3 and 1.7, respectively. Furthermore, CDR was different between each group according to the property of the pulmonary vascular bed, whereas CDL took almost the same value among the five groups. The ventricle works as a converter of atrial blood flow so that it can achieve efficient blood transport.