Combined pressure and volume loading for left ventricular training in patients with congenitally corrected...

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.

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

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.

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.