Right ventricular myocardium in Fallot's tetralogy: a light microscopic, morphometric and ultrastructural study

Area of Science:

• Cardiovascular Pathology
• Pediatric Cardiology
• Surgical Pathology

Background:

• Tetralogy of Fallot (TOF) presents significant hemodynamic challenges to the right ventricle (RV).
• Understanding RV myocardial changes is crucial for managing TOF patients.
• Peroperative assessment can offer insights into disease severity and prognosis.

Purpose of the Study:

• To analyze peroperative RV myocardium biopsies in TOF using light microscopy, morphometry, and electron microscopy.
• To determine the extent of hypertrophy and degenerative changes.
• To correlate these myocardial alterations with clinical and hemodynamic parameters.

Main Methods:

• RV myocardium samples from TOF patients undergoing surgical correction were analyzed.
• Age-matched control samples were used for comparison.
• Light microscopy, morphometry (mean cell diameter), and transmission electron microscopy were employed.

Main Results:

• Hypertrophy was characterized by mitochondrial changes and increased nuclear convolutions.
• Most patients exhibited mild to moderate degenerative changes; severe degeneration correlated with irreversibility.
• Morphological changes significantly correlated with clinical and hemodynamic parameters.

Conclusions:

• Peroperative histomorphometric and ultrastructural evaluation of RV myocardium in TOF reflects hemodynamic stress effects.
• These findings correlate with clinical cardiac dysfunction.
• This evaluation may assist in determining optimal surgical timing and predicting patient outcomes.