Выражение встречается в следующем контексте:

System
The following are cardiac B-Mode System measurements:
One distance
measurements
Interventricular Septum Thickness
Diastolic (IVSd)
Systolic (IVSs)
Inferior Vena Cava (IVC)
Main Pulmonary Artery Diameter (MPA Diam)
Systemic Vein Diameter (Systemic Diam)
Patent Ductus Arterosis Diameter (PDA Diam)
Patent Foramen Ovale Diameter (PFO Diam)
Pericard Effusion Diastole (PEd)
Ventricular Septal Defect Diameter (VSD Diam)
Atrial Septal Defect Diameter (ASD Diam)
Заранее спасибо