Arterial Thromboembolism in a Seven-Month-Old Cat with Acute Myocardial Injury

Transient myocardial thickening is an acute myocardial disease characterized by reversible left ventricular wall thickening that mimics hypertrophic cardiomyopathy and is frequently associated with congestive heart failure. Arterial thromboembolism, a well-recognized complication of hypertrophic cardiomyopathy, has been reported only once in association with transient myocardial thickening. The current report describes a 7-month-old male British Shorthair cat that developed dyspnea 36 h after castration, followed by an acute onset of hindlimb paralysis. On clinical examination, the cat exhibited the classical signs of arterial thromboembolism. Echocardiography revealed a mildly dilated left atrium with ventricular walls of normal thickness, while thoracic ultrasonography identified confluent B-lines. Despite intensive medical management, the clinical condition deteriorated rapidly, and the cat died after approximately 34 h after the onset of paralysis. Post-mortem examination confirmed the presumptive diagnosis of acute myocardial injury. To the authors' knowledge, this is the first reported case of acute myocardial damage with transient myocardial thickening-like presentation, developing within 36 h after a stressful event, with normal ventricular wall thickness on the initial echocardiography, complicated by arterial thromboembolism, and confirmed post-mortem.