Myocardial ischaemia in constrictive pericarditis--a morphometric and electron microscopical study.

Area of Science:

• Cardiology
• Pathology
• Cardiac Surgery

Background:

• Constrictive pericarditis (CP) is a condition characterized by impaired cardiac filling due to pericardial thickening.
• The underlying myocardial pathology in CP has been attributed to disuse atrophy from prolonged cardiac compression.

Purpose of the Study:

• To investigate the myocardial pathology in constrictive pericarditis (CP).
• To compare the myocardial structure in CP with normal controls.
• To determine the primary etiological factor in myocardial dysfunction in CP.

Main Methods:

• Morphometric and morphological examination of left ventricular biopsies from CP patients and atrial septal defect (ASD) controls.
• Ultrastructural analysis of myocardial fibers.

Main Results:

• Myocardial fiber diameters in CP were within normal limits morphometrically, but the range was extended.
• Ultrastructural analysis revealed two types of myofibers in CP: normal and large, oedematous fibers.
• Oedematous fibers showed abnormal nuclei, organelles, and myofibrillar dissolution, indicative of ischemia.

Conclusions:

• Myocardial ischemia, characterized by specific ultrastructural changes, is a significant factor in CP.
• Myocardial ischemia appears to be a more critical factor in the etiology of myocardial dysfunction in CP than disuse atrophy.