Congestive heart failure after enterotomy in a cat with asymptomatic transient myocardial thickening

Transient myocardial thickening (TMT) is characterised by reversible left ventricular myocardial thickening. A 2-year-old castrated male British Shorthair was presented with a history of severe vomiting for 2 days. Based on abdominal radiography and ultrasonography, the cat was diagnosed with an obstructive gastrointestinal foreign body. Preoperative echocardiography revealed an increased maximum left ventricular wall thickness (LVWT: 6.9 mm, measured at end-diastole) and ratio of the left atrium to the aortic root (LA/Ao: 2.1), indicative of a hypertrophic cardiomyopathy phenotype. An enterotomy was performed, and the foreign body was found to be an almond. Immediately after surgery, the cat became tachypnoeic, and thoracic radiography revealed pulmonary oedema. The cat was then treated with cardiac medications. Five days after surgery, the cat's condition clinically normalised. Two months after the first presentation, repeated echocardiography revealed a decreased LVWT (4.8 mm) and LA/Ao (1.58). The cat was diagnosed with TMT, and all cardiac medications were discontinued. The cat remained clinically well for 14 months after the last presentation. This is the first case report to demonstrate that foreign body ingestion may cause TMT, and that congestive heart failure (CHF) can develop after enterotomy in cats with subclinical TMT. The possibility of TMT should be considered in cats with foreign body ingestion that requires anaesthesia and/or surgery because it may trigger CHF, which could ultimately lead to death.