2025 Volume 31 Issue 1 Article ID: oa.25-00077
Purpose: The study investigated the importance of left ventricular volume assessment before primary repair in asymptomatic tetralogy of Fallot (TOF) patients.
Methods: Forty-two asymptomatic TOF patients who underwent preoperative cardiac catheterization at a median age of 4.7 months interquartile range [IQR], 4.0–5.3) between 2013 and 2023 were enrolled. Asymptomatic TOF was defined as room air oxygen saturation ≥85% without duct-dependent circulation. Left ventricular end-diastolic volume (LVEDV) as a percentage of predicted normal (LVEDV%N) was measured using the single-plane area–length method. Correlation with echocardiographic parameters was assessed.
Results: The median LVEDV%N was 107% (IQR, 87.5–139.5). Five patients (11.6%) had LVEDV%N ≤80%. One patient with the lowest LVEDV%N (62%) underwent a modified Blalock–Taussig shunt instead of primary repair. The remaining four patients had a small pulmonary valve annulus (PVA) (Z-score −4.2 to −6.6) and underwent transannular patch repair. Seven additional patients underwent transannular patch repair due to total conal ventricular septal defect (n = 5) or patent ductus arteriosus with small PVA (n = 2). LVEDV%N showed a weak correlation with 1-month echocardiographic parameters (R2 = 0.27–0.347).
Conclusions: Left ventricular volume assessment prior to primary repair is essential in asymptomatic TOF patients. There were cases with small LV for whom primary repair was deferred, or whose PVA was also small; therefore, transannular patch repair was selected.
