Mitral valvuloplasty with left atrial appendage closure and pacemaker implantation in a dog with severe myxomatous mitral valve degeneration: a case report

• Published in: BMC veterinary research Vol. 18; no. 1; p. 184
• Main Authors: Yoshida, Tomohiko, Namiki, Ryosuke, Matsuura, Katsuhiro
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 16-05-2022; BioMed Central; BMC
• Subjects: Animals; Arrhythmia; Atrial Appendage - surgery; Atrial Fibrillation - veterinary; Blood clots; Cardiac arrhythmia; Care and treatment; Case Report; Complications; Congestive heart failure; Degeneration; Dog Diseases - surgery; Dogs; Echocardiography; Edema; EKG; Epicardial left atrial appendage closure device; Fentanyl; Health aspects; Heart failure; Heart rate; Heart surgery; Heart valve diseases; Heart Valve Diseases - complications; Heart Valve Diseases - veterinary; Male; Methods; Mitral Valve; Mitral valve repair; Ostomy; Pacemaker, Artificial (Heart); Pacemaker, Artificial - adverse effects; Pacemaker, Artificial - veterinary; Pacemakers; Pancreatitis; Patients; Postoperative; Postoperative Complications - veterinary; Reperfusion; Rheumatic heart disease; Sick sinus syndrome; Sinuses; Surgery; Thromboembolism; Thrombosis; Thrombosis - veterinary; Veins & arteries; Ventricle; Veterinary surgery; Japan; Germany; Epicardial left atrial appendage closure device; Mitral valve repair; Sick sinus syndrome
• ISSN: 1746-6148; 1746-6148
• DOI: 10.1186/s12917-022-03284-7

Mitral valvuloplasty (MVP) has been widely recognized as a treatment option for myxomatous mitral valve disease (MMVD). However, postoperative complications such as thromboembolism, arrhythmia, and pancreatitis in some cases have resulted in death. We treated a dog with severe MMVD complicated by impaired sinus function with MVP and pacemaker implantation. Also, due to an intrinsic procoagulant state and severe arrhythmia after the MVP, left atrial appendage (LAA) closure was performed to reduce the postoperative risk of thrombosis.
An 11-year-old castrated 7.5-kg male Miniature Schnauzer with a history of congestive heart failure was brought to Shiraishi Animal Hospital for MMVD surgical treatment. Echocardiography revealed an enlarged left atrium and ventricle secondary to MMVD. Sinus arrest with 2 to 3-second periods of asystole was identified by electrocardiogram. Mitral valvuloplasty was performed with cardiopulmonary bypass to treat the MMVD. After coronary reperfusion, there was no spontaneous electrical activity. Cardiac arrest continued. Based on this surgical outcome, a permanent pacemaker was implanted. In addition, LAA closure with an AtriClip was performed to prevent intra-atrial thrombus formation. Cardiac remodeling and congestion were ameliorated after surgery. Sinus rhythm was restored 5 days postoperatively; however, the patient continued pacemaker dependent. All cardiac drugs were discontinued 3 months after surgery. The owner reported no postoperative complications (i.e., thrombosis), and the patient was brought for a check-up 4 months after the operation in good health.
For surgical MMVD cases complicated with impaired sinus function, the chances of spontaneous sinus rhythm are low, requiring pacemaker implantation. LAA closure may be considered to protect against decreased atrial function after mitral valvuloplasty and prevent intra-atrial thrombus formation.