Ventricular perforation is a serious complication of percutaneous myocardial biopsy. Accurate orientation of the biopsy forceps toward the ventricular septum under fluoroscopy is essential to minimise this risk. However, in paediatric patients, variations in ventricular septal orientation complicate proper forceps alignment. No previous studies have addressed this variability in children.

We retrospectively analysed paediatric patients who underwent myocardial biopsy between January 2019 and June 2023. The angle of the ventricular septum relative to the sagittal plane was measured using cardiac CT. Biopsies were performed under fluoroscopic guidance, with individualised angles adjusted to align with the septum. Fluoroscopic images were used to calculate the angle between the biopsy forceps and the septum and the combined angle relative to the sagittal plane.

Sixteen patients underwent a total of 85 biopsies; only the first biopsy per patient was included in the analysis. The mean angle of the septum was 54.3° (range: 30.0–75.0°), the mean angle between forceps and septum was 21.3° (range: 3.5–53.4°), and the combined angle relative to the sagittal plane was 75.6° (range: 45.0–115.7°). No cases of ventricular perforation were observed.

Ventricular septal orientation varies significantly in paediatric patients. Individualised adjustment of fluoroscopic angles based on pre-procedural CT measurements allows accurate positioning of biopsy forceps and may reduce the risk of severe complications.