In cats, hypertrophic cardiomyopathy (HCM) development can lead to congestive heart failure, systemic thromboembolism, and cardiac arrhythmia. The histological features of HCM have been well-studied, but the histological features of mild preclinical cases have never been evaluated. A better understanding of the early stages of HCM can help further the understanding of the causes of HCM and how HCM progresses.
This study included 16 cats, 11 normal and 6 diagnosed with preclinical HCM via echocardiogram. The preclinical HCM group was found to have inflammatory cell infiltrates and increased collagen in the myocardium. The left myocardium contained multifocal areas of inflammatory cells, which were mostly lymphocytes, as well as higher numbers of neutrophils. Additionally, the preclinical HCM group had characteristic histological features of HCM, such as arteriolar mural hypertrophy and interstitial fibrosis, as well as myocardial fiber disarray and cardiomyocyte hypertrophy. The authors recommend further studies to investigate the role of inflammation in HCM progression.
