Left ventricular dysfunction in patients with repaired tetralogy of Fallot is associated with a poor prognosis. Besides, because ventricular diastolic dysfunction predates systolic dysfunction, it is important to diagnose left ventricular diastolic dysfunction at an early stage. However, the mechanism has not been unclear.
The purpose of this study is to investigate the mechanism of a suction force in the left ventricle of patients with repaired tetralogy of Fallot. They have assessed intraventricular pressure gradient "IVPG" as a suction force of blood from the left atrium LV apex during early diastole and left ventricular deformability by using Echocardiography on 38 patients with repaired tetralogy of Fallot and 101 healthy controls. The results showed that IVPG decreased with decreased left ventricular deformability in patients with repaired tetralogy of Fallot. The results suggested that IVPG is a good indicator to diagnose left ventricular diastolic dysfunction in patients with repaired tetralogy earlier. Our company sells software that can measure such IVPG, named iTEcho. It is a software package, including Echo VFM & IVPG.

Maki Kobayashi, Ken Takahashi, Mariko Yamada, Kana Yazaki, Kotoko Matsui, Noboru Tanaka, Sachie Shigemitsu, Katsumi Akimoto, Masahiko Kishiro, Keisuke Nakanishi, Shiori Kawasaki, Masaki Nii, Keiichi Itatani, Toshiaki Shimizu, "Assessment of early diastolic intraventricular pressure gradient in the left ventricle among patients with repaired tetralogy of Fallot", Heart and Vessels , 32 (2017) 1364-1374.