Sick Sinus Syndrome
Sick sinus syndrome is a disturbance
of the normal rhythm of the heart. The electrical
impulse that drives the heart beat starts in the
sinoatrial (SA) node of the heart, and then spreads
through specialized conduction pathways, causing
orderly depolarization and contraction of the heart
muscle. This can be traced on an electrocardiogram.
Sick sinus syndrome is the
name given to a number of arrhythmias (irregular
rhythmns) that arise because of abnormal function
of the SA node. Clinically, the arrhythmias may
cause weakness and fainting.
What breeds are affected
by sick sinus syndrome?
This is seen most often in miniature Schnauzers,
particularly in female dogs.
It occurs less commonly in Pomeranians, dachshunds,
pugs, boxers and cocker spaniels.
For many breeds and many disorders,
the studies to determine the mode of inheritance
or the frequency in the breed have not been carried
out, or are inconclusive. We have listed breeds
for which there is a general consensus among those
investigating in this field and among veterinary
practitioners, that the condition is significant
in this breed.
What does sick sinus syndrome
mean to your dog & you?
The most common clinical signs with this disorder
are weakness and fainting.
How is sick sinus syndrome
The first indication of this disorder may be
that your veterinarian finds your dog has an unusually
slow heart rate, which is not increased by exercise.
To diagnose this further, your veterinarian will
likely perform an electrocardiogram which will show
certain distinguishing features for this condition.
Your dog may have no clinical
signs of this disorder, or may experience fainting