Assessment of early diastolic intraventricular pressure gradient in the left ventricle among patients with repaired tetralogy of Fallot

Abstract

Assessment of left ventricular (LV) dysfunction is vital in patients with repaired tetralogy of Fallot (rTOF). The early diastolic intraventricular pressure gradient (IVPG) in the LV plays an important role in diastolic function. IVPG is calculated as the intraventricular pressure difference divided by the LV length, which allows to account for differences in LV size and therefore calculate IVPG in children. We aimed to investigate the mechanisms of LV diastolic dysfunction by measuring mid-to-apical IVPG as an indicator of the active suction force sucking blood from the left atrium into the LV. We included 38 rTOF patients and 101 healthy controls. The study population was stratified based on age group into children (4-9 years), adolescents (10-15 years), and adults (16-40 years). IVPGs were calculated based on mitral inflow measurements obtained using color M-mode Doppler echocardiography. Although total IVPGs did not differ between rTOF patients and controls, mid-to-apical IVPGs in adolescents and adults were smaller among rTOF patients than among controls (0.15 ± 0.05 vs. 0.21 ± 0.06 mmHg/cm, p < 0.05; 0.09 ± 0.07 vs. 0.17 ± 0.05 mmHg/cm, p < 0.001; respectively). Additionally, only mid-to-apical IVPG correlated linearly with peak circumferential strain (ρ = 0.217, p = 0.011), longitudinal strain (ρ = -0.231, p = 0.006), torsion (ρ = -0.200, p = 0.018), and untwisting rate in early diastole (ρ = -0.233, p = 0.006). In rTOF, the mechanisms underlying diastolic dysfunction involve reduced active suction force, which correlates with reduced LV deformation in all directions.

Impact of pulmonary valve replacement on left ventricular rotational mechanics in repaired tetralogy of Fallot

“…Our findings support and expand upon a small number of previously published works, mostly using speckle-tracking echocardiography [ 20 , 21 , 24 – 31 , 47 ] and a couple using CMR [ 23 , 48 ], that have shown that rotational mechanics are impaired in rTOF. Several studies found that abnormalities in basal rotation were predominantly driving the impairment in torsion [ 20 , 23 , 26 , 29 ].…”

“…More advanced measures of LV myocardial mechanics such as deformation, synchrony, and rotational mechanics may be more sensitive markers of LV dysfunction [ 18 – 23 ]. Rotational mechanics, such as twist and torsion, have been less well studied, but prior reports have indicated that these measures are abnormal in rTOF patients [ 20 , 24 – 31 ], and are associated with adverse outcomes [ 21 ]. Most of these studies used echocardiography to measure rotational parameters which may be technically limited by reduced acoustic windows, particularly in post-operative patients.…”

Changes in left ventricular blood flow during diastole due to differences in chamber size in healthy dogs

“…Intraventricular pressure gradient (IVPG). IVPD was calculated using in-house code written in MATLAB (The MathWorks, Natick, MA) as previously described 13 . Briefly, for the analysis of IVPG, color M-mode apical four chamber views were stored.…”

“…IVPG was calculated by dividing the IVPD by the LVL. To evaluate the segmental pressure difference of each part of the heart, the left ventricle was trisected as previously described 13 . The apical side of the heart was named "apical", the middle part was named "mid", and the basal part was named "basal".…”

Cardiac Function in Infants Born to Mothers With Gestational Diabetes ― Estimation of Early Diastolic Intraventricular Pressure Differences ―

“…The total IVPD was further separated into the basal and mid and apical segments (hereafter, basal and apical segments), as previously described (Figure 2). 8 Furthermore, to overcome differences in LV size, we calculated the IVPG as IVPD/LV length. 8-10, 21 The basal segment was defined as one-third of the total LV length from the mitral valve, whereas the apical segment was defined as the remaining two-thirds.…”