Veterinary cardiologists at Surrey-based North Downs Specialist Referrals (NDSR) have performed what is believed to be the first cutting balloon angioplasty on a cat with double chambered right ventricle.

Sylvie, a four-month-old Maine Coon, was referred to NDSR with a loud heart murmur. Scans revealed she was suffering from a severe obstruction on the right side of her heart which was steadily becoming worse.  

Her condition, double chambered right ventricle, is very rare and, until now, could only be corrected by open heart surgery. However, NDSR specialist cardiologist João Loureiro believed this would be too much of a risk for frail Sylvie, so he opted for a cutting balloon angioplasty which had never been applied to cats before because their hearts are so small. 

He and fellow cardiology specialist Joel Silva carried out the procedure, which involved inserting two balloons on a wire into a vein in Sylvie’s neck and on to her heart. The first had four cutting blades, which were manipulated to score the obstruction before the second was gently inflated in order to relieve it. After the wire and balloons had been removed, the incision in Sylvie’s neck required just two stitches and within 48 hours she was well enough to return home. 

A subsequent scan showed the level of obstruction had been reduced from severe to mild and her owner, Dr Bob Baxter, described her as “much more lively”. 

João, who has a special interest in the treatment of congenital heart disease in small animals, said the decision to perform the interventional ballooning was made because of the risks of open heart surgery and the recent development of veterinary applications of the cutting balloon technique. 

João said: "As Sylvie’s condition was so rare, wider application of the technique is limited in terms of the number of cats which could benefit from it. However, it is extremely relevant to those individuals who are affected and could be of use in the treatment of other, more common, conditions."

Joel said: "Cutting balloon angioplasty is routinely used in human medicine for treating narrowed and stiffened blood vessels and has recently been adapted to treat a heart condition in dogs but we believe this may be the first time it has been used to treat this condition in a cat."

Photo: Sylvie recovering with NDSR cardiology nurse Francesca Adams