Listen to your (pet's) heart: heart block in pets

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Posted by Dr. Nina Mantione on Aug 15 2012



Did you know that dogs and cats can sometimes need pacemakers? It is rare, but there are pets who have some help to keep their hearts beating in a normal rhythm – including Emma, a 5-year-old Greyhound whose pacemaker was covered by her Petplan pet insurance.

Emma’s device was implanted to correct heart block, the condition that typically leads to the need for pet pacemakers. Heart block occurs when there is an abnormality in the rhythm of the heartbeat that creates a prolonged pause between beats.
Instead of the comforting sound of “lub-dub,lub-dub, lub-dub,” the heart experiencing heart block may sound something like, “lub-dub, lub-dub………..lub-dub,” or the pet’s heart rate might be drastically slow. There are different types of heart block, depending on how the rhythm of the heart is affected, and likewise, there are a number of different causes.
Sometimes, heart block is caused by a primary abnormality of the heart itself, an aberrant electrical pathway that the pet was either born with or developed during his life. It can also be caused by outside influences such as pulmonary disease, inflammation or infections within the chest or heart, medications and other underlying heart disease.

In some cases, a pet with heart block may be asymptomatic, and the condition is only picked up by chance on a physical exam or a preoperative ECG. In more severe cases, it causes symptoms ranging from weakness, lethargy, exercise intolerance and collapse from fainting.
Treatment depends on the severity of the arrhythmia and the underlying cause, which, if one exists, always needs to be addressed. For cases without an underlying cause, or one in which it is impossible to address, the only successful management is with an implanted pacemaker. This device acts as a failsafe to keep the heart beating in a regular rhythm, even when its own electrical conduction fails.

Heart block is a condition that absolutely should be evaluated by a veterinary cardiologist. It can be life-threatening and difficult to manage, and pacemaker implantation and management is best done by a board-certified specialist.