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Fatal mitochondrial cardiomyopathy in Kearns-Sayre syndrome
Insights
Kearns-Sayre syndrome can cause fatal mitochondrial cardiomyopathy, leading to heart failure. Mitochondrial anomalies in the heart
Area of Science:
- Cardiology
- Neurology
- Mitochondrial Diseases
Background:
- Kearns-Sayre syndrome is a rare mitochondrial disorder.
- It affects multiple organ systems, including the heart.
Observation:
- A 26-year-old male with Kearns-Sayre syndrome presented with cardiac arrhythmias and congestive cardiomyopathy.
- Postmortem examination revealed an enlarged heart with fibrosis and dilation of the left ventricle.
Findings:
- Histological analysis showed myofibril loss and enlarged mitochondria with abnormal cristae in heart muscle cells.
- Mitochondrial anomalies were also found in the heart's conductive system cells.
Implications:
- This case highlights Kearns-Sayre syndrome as a cause of fatal mitochondrial cardiomyopathy.
- Mitochondrial dysfunction in the conductive system may explain cardiac conduction abnormalities in this syndrome.
Abstract:
The clinical and postmortem findings in a 26 year old man with Kearns-Sayre syndrome are described. In the last years of his life he suffered from cardiac arrhythmias and a congestive cardiomyopathy, dying of cardiac pump failure. The heart was enlarged, especially the left ventricle which was fibrotic and excessively dilated. Histological and fine structural investigation revealed an excessive loss of myofibrils and an increase of enlarged mitochondria with lamellar and atypically tubular cristae in widespread heart muscle cells. Mitochondrial anomalies were also observed in some cells of the conductive system. This patient thus suffered not only from a mitochondrial myopathy with ragged red fibers but also from a fatal mitochondrial cardiomyopathy. The anomalies observed in the mitochondria of the conductive system cells suggest that the well-known conductive abnormalities in patients with Kearns-Sayre syndrome might be at least partly caused by disturbed function of these mitochondria.