Mia is a very friendly 8 year old Staffordshire bull terrier; she was brought in by her owner with occasional collapse episodes on walks. She didn’t collapse for long and would soon be up on her feet again and didn’t appear unwell in any other way.
When the vet first examined her there was nothing found to be wrong and it remained a mystery until the collapse became more frequent. This time on examination she was found to have an intermittent very slow heart rate, known as bradycardia. Periods of normal heart beats and then abnormal ones or variable heart rate is known as an arrhythmia and this was recorded on an electrocardiogram or ECG. It was thought that this may be the cause of Mia’s fainting problems so she was referred to a cardiology specialist for further tests.
A heart scan ‘echocardiogram’, was normal as was her heart rate on the day so it was necessary to fit her with a halter ECG. This device is worn by the patient and monitors and records the heart rhythm or ‘trace’ over a 24 hour period. This showed there were abnormal periods of heart rate confirming the problem.
As no structural heart abnormalities or diseases were found to explain the condition, she was diagnosed with ‘sick sinus syndrome’, a rare problem with the electrical signal that keeps the heart beating.
The only treatment for this was for Mia to have a pacemaker fitted at Bristol Veterinary School. Similar to those used in humans, this device takes over control of the heart beat and ensures it beats fast enough to allow Mia to enjoy her walks again.
Further check-ups have shown it to be working well and Mia is back to her normal self.