SSS is diagnosed by performing an electrocardiogram (ECG). Some animals may be asymptomatic in the early stages of the disease and will be detected by a veterinarian during a routine physical examination. This further contributes to a slower than normal and irregular heart rate/rhythm.Īffected animals with SSS will typically present with signs of exercise intolerance, weakness, lethargy (sleeping more) and fainting. When the AV node becomes involved, the electrical signal is blocked and does not enter the ventricles leading to failure of activation of the ventricles. Affected animals may occasionally have periods of tachycardia (fast heart rates). Many animals with SSS will have a slower than normal heart rate with frequent pauses between heartbeats. As a result of this infiltration of the SA node it begins to depolarize haphazardly in an irregular fashion. The exact etiology is unknown, but it has been shown that in affected Schnauzers the pacemaker cells in the SA node are replaced largely by fibrous (scar) tissue. In animals with SSS there is dysfunction of the SA node and in some cases, the AV node is also involved. After the SA node depolarizes (fires), the electrical signal travels through the atria and enter the lower heart muscle chambers (ventricles) through the atrio-ventricular (AV) node. This is considered the pacemaker (command centre) of the heart and sets the rhythm and rate of the heartbeat. In a normal heart, the stimulus to cause the heart to contract originates from a collection of specialized cells called the sino-atrial (SA) node which is located within the right atrium. The Miniature Schnauzer, West Highland White Terrier and Cocker Spaniel are three breeds which are commonly diagnosed with SSS. Sick sinus syndrome (SSS) is an acquired disease of the conduction (electrical) system which is typically diagnosed in geriatric dogs.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |