*3.1. Clinical and Cardiological Characteristics*

Patient demographics and outcomes are shown in Table 1 and Figure 1. Overall, 53 patients (25 males and 28 females) were enrolled in this study. Their age at diagnosis ranged from 0 to 14 years (median: 0.3 months). The median follow-up period was 3.0 years (0.5–17.0 years). A total of 11 patients (20.8%) reported a family history of cardiomyopathy; 23 (43.4%) were diagnosed with CHF, 14 with heart murmur (26.4%), and 6 with cyanosis (11.3%). During the observation period, 31 patients (58.5%) experienced CHF and 13 (24.5%) developed arrhythmias such as ventricular tachycardia, supraventricular tachycardia, and atrioventricular block. No patient had a history of thrombosis. Other systemic malformations were observed in 10 patients (18.9%; Table S3).


**Table 1.** Comparison of physical findings of patients with LVNC and VSD.


**Table 1.** *Cont.*

LVNC-CHD; left ventricular noncompaction with congenital heart disease, VSD; ventricular septal defect, CM; cardiomyopathy, VT; ventricular tachycardia, SVT; supra ventricular tachycardia, CAVB; complete AV block, AFL; atrial flatter, HF; heart failure, ASD; atrial septal defect, PDA; patent ductus arteiosus, Ebstein; Ebstein's anomaly, DORV; double outlet of right ventricle, CoA; coarctation of aorta, PS; pulmonary valve stenosis, AS; aortic valve stenosis, hypo RV; hypoplastic right ventricle, PV; pulmonary valve, IAA; interruption of aortic arch, MA; mitaral vavle atresia, PA; pulmonary valve atresia, TA; tricuspid valve atresia, TGA; transposition of the great arteries, TOF; tetralogy of Fallot, TS; tricuspid valve stenosis, BVR; biventricular repair, PAB; pulmonary artery banding, bil PAB; bilateral pulmonary artery banding, PTPV; percutaneous transvenous pulmonary valvuloplasty, PTAV; percutaneous transvenous artery valvuloplasty, LBBB; left bundle branch block, RBBB; right bundle branch block, LQT; long QT. Continuous variables between the group of LVNC with VSD and the group of VSD were compared using the unpaired t-test, non-parametric Mann–Whitney test, or one-way analysis of variance, and categorical variables were compared using χ<sup>2</sup> statistics or Fisher's exact test, as appropriate.

According to the type of CHD, 29 patients (54.7%) had VSDs, 17 (32.1%) had atrial septal defects, 10 had patent ductus arteriosus (PDA), and 7 (13.2%) had Ebstein's anomaly and double outlet right ventricle.

A total of 30 patients underwent surgery at, on average, 11.2 months of age; 19 underwent biventricular repair (BVR); and 2 underwent pulmonary artery banding (PAB), bilateral PAB, and PDA ligation. Moreover, 13 patients (43.3%) were diagnosed with LVNC postoperatively (Figure 1).

Upon electrography, fragmented QRS was frequently observed in 16 patients (40.0%), followed by right bundle branch block (25.0%), T-wave abnormality (20.0%), Q wave (17.5%), J wave (17.5%), ST-segment depression (12.3%), and long QT syndrome (12.5%).

**Figure 1.** Flowchart of included and excluded patients. Thirty patients underwent surgery and the condition of 8 worsened postoperatively. Adverse events were noted in 4 patients.
