Anaesthesia of a cat with complex cardiac malformation

A two-year-old Maine Coon queen was diagnosed with a complex cardiac malformation after pre-anaesthetic detection of a heart murmur IV/VI. The cat was found to have a double-chambered right ventricle, a ventricular septal defect as well as a mitral valve dysplasia. For elective ovariectomy, anaesthesia was performed using a balanced technique and close monitoring with respect to the fragile cardiovascular situation. After premedication with intravenous fentanyl, anaesthesia was co-induced with alfaxalone and midazolam and maintained with sevoflurane in oxygen and air, as well as a fentanyl variable rate infusion. In addition, local anaesthetic measures completed the perioperative analgesia. Dopamine was infused at a low rate to support cardiovascular function. After initial mechanical ventilation the cat was able to breathe spontaneously throughout the procedure. Additional support included careful positioning and continuous warming techniques. Invasive blood pressure measurement and arterial blood gas analyses complemented basic monitoring. Buprenorphine was administered for postoperative analgesia. Anaesthesia and recovery were uneventful and the cat was discharged the same day.