Luis Pasteur Zoonosis Institute,, Buenos Aires, Argentina.
Veterinaria UCIcoop, Buenos Aires, Argentina.
Open Vet J. 2021 Jul-Sep;11(3):468-470. doi: 10.5455/OVJ.2021.v11.i3.20. Epub 2021 Sep 4.
Myocardial infarction (MI) is an important cause of death and disability among humans worldwide. Few studies have reported the occurrence of MI in small animals as well. Reports in human medicine indicate that up to 30% of patients with clinical signs compatible with myocardial ischemia suggestive of coronary disease exhibit normal epicardial arteries at angiography. These symptoms have been associated with a syndrome characterized by alterations in cardiac microvasculature, known as coronary microvascular dysfunction (CMD).
This study aimed to describe the necropsy findings and clinical-pathological characterization (when available) of cats with histopathological findings suggesting CMD.
Necropsy records of cats presenting histopathological diagnosis compatible with acute and/or chronic MI, with normal epicardial arteries and microvascular disorders were evaluated.
Twenty animals met the inclusion criteria. Eight cats (40%) exhibited findings compatible with mild hypertrophic cardiomyopathy (HCM) without left atrial enlargement, one (5%) presented restrictive cardiomyopathy, and another one (5%) had lesions consistent with histiocytoid cardiomyopathy. The remaining cats (50%) showed alterations compatible with severe HCM with left atrial enlargement. In all cases, epicardial arteries were normal (without obstruction). All the evaluated hearts exhibited myocardial multifocal fibrosis along with replacement of cardiomyocytes by adipose tissue and blood vessels with hyperplasia and hypertrophy of the muscular layer with protrusion of the nuclei of the endothelial cells.
These findings suggest the presence of microvascular dysplasia of the coronary arteries. Further studies are necessary to confirm and clinically characterize these results.
心肌梗死（MI）是全球人类死亡和残疾的重要原因。少数研究也报道了小动物发生 MI 的情况。人类医学报告表明，多达 30%的临床症状符合心肌缺血、提示冠心病的患者在血管造影时表现出正常的外膜动脉。这些症状与一种以心脏微血管改变为特征的综合征有关，称为冠状动脉微血管功能障碍（CMD）。
本研究旨在描述组织病理学检查发现符合 CMD 的猫的剖检结果和临床病理特征（如有）。
评估了具有组织病理学检查诊断为急性和/或慢性 MI、正常外膜动脉和微血管紊乱的猫的剖检记录。
20 只动物符合纳入标准。8 只猫（40%）表现出符合轻度肥厚型心肌病（HCM）的表现，无左心房扩大，1 只（5%）表现出限制型心肌病，另 1 只（5%）表现出组织细胞型心肌病的病变。其余猫（50%）表现出严重 HCM 伴左心房扩大的改变。在所有情况下，外膜动脉均正常（无阻塞）。所有评估的心脏均表现出心肌多灶性纤维化，伴有脂肪组织和血管替代心肌细胞，以及血管平滑肌层增生和肥厚，内皮细胞核突出。
这些发现提示存在冠状动脉微血管发育不良。需要进一步研究来证实和临床描述这些结果。
