Journal of Pediatric Cardiology and Cardiac Surgery

Background: The crochetage pattern is an important finding in atrial septal defect (ASD); however, the reason for this pattern is unclear. We hypothesized that the crochetage pattern is related to the right ventricle stretch direction.

Methods: Stretch values were calculated in eight ASD patients with the crochetage pattern, eight ASD patients without the crochetage pattern, and eight controls who underwent cardiac catheterization. The right ventricle systolic area was subtracted from the right ventricle diastolic area in posteroranterior (PA) and left lateral views on right ventricle angiography. The area was divided into three parts at the position of the tricuspid valve and adjusted according to body surface area.

Results: ASD patients with the crochetage pattern did not have significantly higher pulmonary/systemic blood flow ratios or right ventricle end diastolic volume indices than those without the crochetage pattern. Stretch values towards the left were higher in ASD patients with the crochetage pattern than in controls. Stretch values in the lower direction in the PA view were higher in ASD patients with the crochetage pattern than in those without the crochetage pattern. Multiple regression analysis revealed that stretch values in the lower direction in the PA view influenced the number of crochetage patterns.

Conclusion: ASD patients with the crochetage pattern have significantly higher stretch values in the lower and left directions in the PA view than those without the crochetage pattern and controls. Stretch values in the lower direction of the right ventricle are associated with the crochetage pattern in ASD patients.