Left Ventricular Torsion Obtained Using Equilibrated Warping in Patients with Repaired Tetralogy of Fallot.

Patients after surgical repair of Tetralogy of Fallot (rTOF) may suffer a decrease in left ventricular (LV) function. The aim of our study is to evaluate a novel method of assessing LV torsion in patients with rTOF, as an early indicator of systolic LV dysfunction. Motion tracking based on image registration regularized by the equilibrium gap principle, known as equilibrated warping, was employed to assess LV torsion. Seventy-six cases of rTOF and ten normal controls were included. The group of controls was assessed for reproducibility using both equilibrated warping and standard clinical tissue tracking software (CVI42, version 5.10.1, Calgary, Canada). Patients were dichotomized into two groups: normal vs. loss of torsion. Torsion by equilibrated warping was successfully obtained in 68 of 76 (89%) patients and 9 of 10 (90%) controls. For equilibrated warping, the intra- and interobserver coefficients of variation were 0.095 and 0.117, respectively, compared to 0.260 and 0.831 for tissue tracking by standard clinical software. The intra- and inter-observer intraclass correlation coefficients for equilibrated warping were 0.862 and 0.831, respectively, compared to 0.992 and 0.648 for tissue tracking. Loss of torsion was noted in 32 of the 68 (47%) patients with rTOF. There was no difference in LV or RV volumes or ejection fraction between these groups. The assessment of LV torsion by equilibrated warping is feasible and shows good reliability. Loss of torsion is common in patients with rTOF and its robust assessment might contribute into uncovering heart failure in an earlier stage.

Home Monitoring Program Reduces Mortality in High-Risk Sociodemographic Single-Ventricle Patients.

A clinician-driven home monitoring program can improve interstage outcomes in single-ventricle patients. Sociodemographic factors have been independently associated with mortality in interstage patients. We hypothesized that even in a population with high-risk sociodemographic characteristics, a home monitoring program is effective in reducing interstage mortality. We defined interstage period as the time period between discharge following Norwood palliation and second-stage surgery. We reviewed the charts of patients for the three-year period before (group 1) and after (group 2) implementation of the home monitoring program. Clinical variables around Norwood palliation, during the interstage period, and at the time of second-stage surgery were analyzed. There were 74 patients in group 1 and 52 in group 2. 59 % patients were Hispanic, and 84 % lived in neighborhoods where over 5 % families lived below poverty line. There was no significant difference in pre-Norwood variables, Norwood discharge variables, age at second surgery, or outcomes at second surgery. There were more Sano shunts performed at the Norwood procedure as the source of pulmonary blood flow in group 2 (p value <0.05). There were more unplanned hospital admissions and percutaneous re-interventions in group 2. Patients in group 2 whose admission criteria included desaturation had a 45 % likelihood of having an unplanned re-intervention. Group 2 noted an 80 % relative reduction in interstage mortality (p < 0.01). In a multiple regression analysis, after accounting for ethnicity, socio-economic status, and source of pulmonary blood flow, enrollment in a home monitoring program independently predicted improved interstage survival (p < 0.01). A clinician-driven home monitoring program reduces interstage mortality even when the majority of patients has high-risk sociodemographic characteristics.