Minimally invasive cardiac procedures (sometimes called interventional procedures) are a category of treatments for certain heart conditions that allow the veterinary cardiologist to treat or correct the problem without invasive heart surgery.
These procedures include:
They are performed in a cardiac cath lab. Fluoroscopy (video X-rays) and echocardiography (ultrasound of the heart) provide imaging to help guide the procedure in the cath lab.
The animals are placed under anesthesia and are closely monitored. A catheter is placed into a vein or artery in either the groin or the neck providing access to the vessel. Then a thin guide wire is passed through the catheter into the vessel and is advanced under image guidance to the area of interest in or near the heart.
In most types of minimally invasive cardiac procedures, a long catheter is then passed over the guide wire. Contrast solution is injected through the catheter; this creates a roadmap (angiogram) that is viewed on the fluoroscopy unit. Once the catheter or guide wire is placed, the interventional device is passed into position. This is usually a balloon catheter (if the defect needs to be stretched out), an occluder or coil (if the defect needs to be plugged up) or an electrode (if an abnormal heart rhythm needs to be corrected).
The most common conditions treated this way are several congenital heart defects and some types of arrhythmias. A partial list of conditions treated by minimally invasive cardiac procedures includes:
In the near future, we may also be able to treat degenerative valve disease (the most common type of heart disease in dogs) via a minimally invasive method.
The signs and symptoms vary depending on the underlying heart disease. The symptoms associated with the congenital heart diseases can include:
The various arrhythmias treated with minimally invasive procedures are characterized by either very fast or slow heartbeats. The resulting symptoms include weakness, collapse, and syncope (fainting). In some cases, heart failure can develop which will lead to fluid accumulating in the chest and/or abdomen producing labored breathing.
These various conditions are diagnosed based on a review of the clinical signs and history followed by a physical examination, and a combination of tests including chest radiographs (X-rays), echocardiogram (ultrasound imaging of the heart) and ECG (electrocardiogram). Once the initial testing is performed, a cardiac catheterization may be performed to record pressures across a narrowing or measure the volume of blood being shunted across a defect. In some cases, an angiogram will be needed to determine what size device will be needed to close a defect. The angiogram will also provide the road map to follow to position the device in the proper location.
Once all of the diagnostics and are completed the intervention (treatment) is performed.
After these procedures are completed, the patients are monitored closely overnight and usually discharged the following day.
The prognosis for these different diseases after the procedures have been performed is generally very good but may vary on a case to case basis. The patient’s status should be monitored at regular intervals by the Veterinary Cardiologist to ensure the best possible outcome.