An enlarged heart can complications in surgery. Enlarged hearts are not specific to a particular breed, but they tend to afflict large and giant breeds as well as dogs who are middle-aged or older. The disease of the heart occurs in young or small dogs as well, but not as commonly. Due to several medical concerns, living with the condition can become tricky when surgery is required because of some other ailment.
Anesthesia and Sedation
Veterinary anesthesia is quite safe, even for most dogs with cardiac disease, when a complete physical exam, pre-anesthetic blood work and cardiac monitoring is performed. The American Animal Hospital Association mandates breathing tubes for all patients undergoing general anesthesia, which allows patients with heart problems to breath comfortably and clearly during surgery. It is also crucial for these patients to receive intravenous fluid therapy before, during and after anesthesia.
Conflicts With Medication
Anesthesics could interfere with various medications a dog may be taking to help with his enlarged heart. If this isn't the case, post-op medications may do the same while the dog is healing.
In an enlarged heart, the capillaries don't refill with blood as quickly as they should, which hurts the exchange of oxygen and carbon dioxide, and causes anemia. Because the heartbeat may be affected by the enlargement of the organ, the flow of blood can be a concern for a dog in surgery, since anemia requires the heart to beat harder to supply the oxygen the body requires. Extended periods under anesthesia can be dangerous for this reason.
If an enlarged heart comes with an arrhythmia, or abnormal heartbeat, complications during surgery may increase. Arrhythmia comes in many forms that can be treated in many ways, from medicinal to surgical. The danger is that an arrhythmia can cause a heart attack or outright heart failure at any moment whether a dog is in surgery or otherwise. Abnormal heartbeats also hinder blood flow and oxygen throughout the body.