Knocking on Heaven’s Door: A Left-Atrial Ball-Like Thrombus in a Cardiomyopathic Cat with Cardioimyopathy, Atrila Fibrillation and Triplegia

Congestive heart failure (CHF) and systemic arterial thromboembolism (ATE) are the most common clinical complications in cats with hypertrophic cardiomyopathy (HCM). We describe a 7-year-old, male castrated domestic short hair cat with a free floating ball thrombus (FFBT) in the left atrial cavity. The cat was diagnosed with HCM, atrial fibrillation, suspected myocardial infarction, ATE affecting three limbs, and a large, sonographically heterogenic, counterclockwise-rotating, left atrial FFBT. An intra-cardiac FFBT is a rare finding in cardiomyopathic cats with a pro-thrombotic state, some of which present with co-morbidities. This condition likely further increases the already high risk of thromboembolization. Systemic embolization can lead to multiple fragments lodging in one or several downstream coronary and systemic arteries, resulting in devastating complications, and likely worsening prognosis.