Histologic alterations in tetralogy of Fallot.

Area of Science:

• Cardiology
• Pediatric Cardiac Surgery
• Histopathology

Background:

• Tetralogy of Fallot (TOF) is a congenital heart defect.
• Histologic alterations may exist before complete surgical repair.
• These alterations might impact early postoperative outcomes.

Purpose of the Study:

• Investigate pre-existing histologic alterations in TOF patients at the time of complete repair.
• Evaluate the impact of these alterations on early postoperative outcomes.

Main Methods:

• Compared 14 patients with TOF (7 acyanotic, 7 cyanotic) undergoing complete repair.
• Examined right ventricular biopsies for cardiomyocyte injury, fibrosis, and mitochondrial damage.
• Assessed correlations between histologic findings and postoperative outcomes (inotrope use, ICU/hospital stay).

Main Results:

• Cyanotic TOF patients had higher inotrope scores, longer ICU and hospital stays.
• Cyanotic TOF patients exhibited greater cardiomyocyte injury, mitochondrial damage, and fibrosis.
• No correlation found between histologic alterations and early surgical outcomes.
• History of spells correlated with worse early surgical outcomes.

Conclusions:

• Pre-existing cardiomyocyte injury, mitochondrial damage, and fibrosis are more pronounced in cyanotic TOF.
• Early surgical repair of TOF may prevent the development of histopathologic alterations.