Combined pressure and volume loading for left ventricular training in patients with congenitally corrected transposition of the great arteries

Objective: Patients with congenitally corrected transposition of the great arteries may require left ventricular training before the double switch operation. We evaluated the effects of combined pressure and volume loading.

Methods: We performed a retrospective study of patients with congenitally corrected transposition of the great arteries who underwent left ventricular training between 2012 and 2022.

Results: Fifteen patients underwent left ventricular training at a median age of 1.5 years (interquartile range [IQR], 0.7-5.6). Their median left ventricular mass index was 21 g/m² (IQR, 18.9-36.6), left ventricular end-diastolic volume index was 65.1 mL/m² (IQR, 40.6-84.6), and systolic left ventricular/right ventricular pressure ratio was 0.35 (IQR, 0.31-0.5). In addition to pulmonary artery banding, atrial septectomy was performed in 12 patients (80%). Two patients already had a relevant shunt. One patient required systemic ventricular assist device implantation and heart transplantation. After a median of 1.9 years (IQR, 0.8-4.4), left ventricular mass index had increased to 38.5 g/m² (IQR, 25-49, P = .002), left ventricular end-diastolic volume index to 71.4 mL/m² (IQR, 50.1-94.4, P = .13), and systolic left ventricular/right ventricular pressure ratio to 0.94 (IQR, 0.84-1.1, P = .002). Older patients demonstrated a lower increase in left ventricular pressure. Six patients (6/14, 43%) have met eligibility criteria for the double switch operation (5 performed). Their age at the time of pulmonary artery banding was 1.7 years (IQR, 0.5-3.7), and the time between pulmonary artery banding and double switch operation was 3.1 years (IQR, 1.5-5.2). One patient required double switch operation takedown due to left ventricular failure. Two older patients were considered nonresponders to left ventricular training.

Conclusions: Combined pressure and volume loading resulted in a significant increase in left ventricular mass index and left ventricular pressure. Among older patients, there were nonresponders who remained not suitable for the double switch operation.