Atrial Tear in Dogs

The heart is divided into four chambers. The upper chambers are called atria (atrium, singular), and the lower chambers are called ventricles. When the atrial wall is forced to expand more than it is capable, a tear may occur. This expansion is typically caused by an increase in volume and pressure to the left atria. Atrial tears are more common in small to medium sized dogs, older dogs, and is particularly prominent in the following breeds: Poodle, Dachshund, the Cocker Spaniel and Shetland Sheepdog.

A tear in the heart produces many symptoms consistent with other heart diseases. If your pet has an existing heart condition, it is possible that this could be a symptom of, or along with, an atrial tear.

• Weakness or collapse – may follow excess activity or excitement
• Cough
• Difficult breathing
• Increased heart rate
• Weakened pulse
• Heart murmurs, arrhythmia, or other common signs of cardiac disease

Types

Tears in the heart are easiest classified by the location and degree of the tear. By distinguishing these factors, possible concerns can be determined.

• Incomplete - If the tear in the atrium isn’t a complete tear, it’s possible that it will be temporarily sealed. From this, the tear will either heal or continue until it is a complete tear.
• Complete - A complete left atrial tear will likely lead to bleeding into the pericardial sac and can be life-threatening.
• Interatrial septum (a wall of tissue dividing the two uppermost atria chambers of the heart) - If the tear occurs on the dividing atrium wall, an atrial septal defect may result.

Atrial tears are typically caused by an increase in volume or pressure to the left atria that forces it to expand more than it is capable. Some conditions that cause this are:

• Mitral valve endocardiosis - which results from the leaking of the mitral valve. The mitral valve is responsible for blood flow to and from the heart.
• Chordae tendineae rupture - which is when the chordae tendineae (strong, fibrous strings that attach to the lower chamber of the heart connecting the papillary muscles and the ventricle) rupture.
• Trauma to the chest - such as blunt force from an object or being hit by a car.
• Cardiac neoplasia - the abnormal growth of tissue in the heart. The most common cardiac neoplasia to cause tears in the atrial wall is hemangiosarcoma.
• Cardiac catheterization - the threading of a catheter to your heart in order to diagnose heart conditions or otherwise monitor health.

Diagnosis may be made through one, many, or all of the below tests, depending on your pet’s symptoms and overall health.

• Physical exam
• Urinalysis
• Laboratory tests to measure NT-proBNP and TnI levels
• X-rays
• Echocardiography, which uses ultrasound to learn about the action of the heart

Your veterinarian will use these tests to determine if your pet suffers from an atrial tear, as well as to rule out other possible heart problems or health issues that could be causing your pet’s symptoms.

Depending on the outcome of the examination and the following diagnosis, treatment may vary.

• In the event of a left atrial tear, pericardiocentesis, a process that uses a needle to remove fluid from the pericardial sac, may be used as a means of treatment, though it will be difficult.
• Your veterinarian may recommend a treatment process that aims to reduce the pressure in the left atrium. This will likely use medication combinations, such as diuretics and arterial vasodilators (used to dilate arteries).
• Surgery may be completed to remove the pressure on the left atrium, but this could be risky.

Recovery and management will vary depending on the course(s) of treatment your veterinarian advises. Your pet will need to be monitored closely following the treatment, specifically for respiratory rate, pulse quality, and heart rate. Blood pressure monitoring may be done if arterial vasodilators are used. Your veterinarian may want to do follow-up with echocardiography to monitor potential clotting. Close follow-up is usually recommended for 2-3 months after. There is a low survival rate for pets with atrial tears. For those who do survive, life expectancy is limited to several months, perhaps longer with close monitoring, management, and cage rest.

The cost will vary depending on the diagnostic tests your veterinarian chooses to run. The total cost for diagnostic tests, which includes a physical exam, urinalysis, lab tests, x-rays, and echocardiography, is expected to be around $850. Treatment may include pericardiocentesis, medications, or pressure removal, coming in around $1,200. Your actual cost will vary depending on diagnosis and treatment courses, as well as pharmacy and veterinarian specifications. If surgery is required, the total estimated cost could reach $3,600, with additional supportive monthly costs ranging from $175 to $250.