A case of Left Ventricular endocardial fibrosis in a cat

1. A8-034732 A case of Left Ventricular endocardial fibrosis in a cat Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only Leonardo Susta, DVM JanildoLudolf Reis, DVM Elizabeth W. Howerth, DVM, Ph.D

2. Signalmentand History • 5 yr, female, DSH cat • Acute onset of illness • Respiratory distress • Died soon after presentation at the veterinary clinic Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

3. Gross Findings • Petechiation on the lung • Pulmonary edema • Mottled liver with accentuation of lobular pattern • Heart was moderately enlarged and rounded Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

4. Microscopic findings • Heart The left ventricular endocardium is severely expanded by a thick layer of fibrosis Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

5. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

6. Microscopic findings The underlying myocardium shows: • extensive myofiber loss • replacement by fibrosis • increased number of small vessels • scattered infiltrating lymphocytes and macrophages are present Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

7. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

8. Masson Trichrome Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

9. Microscopic findings • In the remaining parenchyma, there are multiple foci of fibrosis • Multifocally, the myocardial fibers show disarray Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

10. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

11. Microscopic Findings Lungs: • Multifocally, the alveolar septa are thickened by a moderate amount of fibrous tissue and type II cells hyperplasia. • Rare bronchioles and alveolar ducts are filled by foamy macrophages which give to the lung a patchy consolidated appearance. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

12. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

13. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

14. Anatomic Diagnosis • Heart: Left ventricular endocardial fibrosis and hypertrophic cardiomyopathy. • Lung: multifocal to coalescing interstitial pneumonia with type cell II hyperplasia and fibrosis Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

15. Discussion • Left endocardial ventricular fibrosis (LEVF) was previously named as restrictive cardiomyopathy • It is the less common cardiomyopathy in cats • It cause diastolic deficit with decreased cardiac output • Two forms of restrictive cardiomyopathy are present: - Subendocardial fibrosis - Eccess of moderator bands that trasverse the left chamber • The subendocardial fibrosis has been associated with endomyocarditis Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

16. Discussion • In an extensive survey, 28% of cats suffering from LEVF had interstitial pneumonia • Causation or concomitant underlying cause for both the lesions? • In our case LEVF was associated with histological lesions of cardiac hypertrophy. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

17. Acknowledgment: Dr. Janildo L. Reis Dr. Raquel Rech Dr. Elizabeth W. Howerth Dr. Corrie Brown Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

18. Questions? Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only Thank you!