Reply to Van den Eyde et al.

Abstract

We read with interest the letter to the editor by Van den Eyde et al. [1] regarding our recently published study presenting the results from serial right ventricular (RV) assessment with cardiovascular magnetic resonance (CMR) in patients with hypoplastic left heart syndrome (HLHS) [2]. First, we would like to thank the authors for their positive comments and their interest in our work. Van den Eyde et al. [1] brought several interesting aspects to our attention, and we agree that it is worth to discuss them. Our study aimed to assess the fate of the RV during follow-up after Fontan completion and we found a significant increase in indexed RV volumes in HLHS patients >10 years but only a mild reduction in RV ejection fraction. As discussed by Van den Eyde et al., physiological changes due to puberty might play an important role in RV deterioration. The raising systolic and diastolic blood pressure and the subsequently increased RV afterload in puberty [3] should be considered as a potential reason for the increase in RV size. Although it seems likely that gender differences in blood pressure during puberty, probably related to a different pattern of sex hormones [3, 4], also impact RV size in HLHS patients, we could not find a difference between boys and girls suggesting that other factors might be more important. In this context, the study by Liu et al. [5] that was cited by Van den Eyde et al. [1] is indeed of great interest as it pays attention to cardiovascular changes during puberty related to hypoxia in patients with congenital heart disease. Cyanosis is common in HLHS patients, if the fenestration in the Fontan tunnel is patent, and is a known factor that contributes to heart failure in congenital heart disease patients [6]. It seems therefore reasonable to consider this aspect and related metabolic changes in future studies.