Review of cardiac arrhythmias in dogs
Cardiac arrhythmia is a violation of the heart rhythm in dogs. These disorders are classified based on the area of the heart in which they occur. They originate either from the upper parts of the heart, the lower parts of the heart, the region of the heart responsible for the heartbeat, or from the electrical conductivity system in the heart.
Each heartbeat arises as an electrical impulse in the upper right heart chamber (sinoatrial [SA] node). Then the impulse passes through the upper chambers of the heart (atrium) to the intermediate station (atrioventricular [AV] node), and, finally, in the lower chambers of the heart (ventricles). An electrical impulse generates a typical pattern observed on an electrocardiogram (ECG or ECG). Disruption in the generation or transmission of an electrical impulse to the heart causes cardiac arrhythmia. Some cardiac arrhythmias are temporary and do not cause disease. Others are serious and can be life-threatening.
Heart rhythm disorders can affect dogs of any age or gender. They can also affect any breed, but there are some breeds that are more at risk for developing arrhythmias than others. Giant dog breeds are more prone to the type of arrhythmia, known as atrial fibrillation, which is a rapid abnormal heartbeat that occurs in the atria. Labrador retrievers tend to supraventricular tachycardia, which is a rapid heartbeat that occurs directly above the ventricles. Pinchers and Doberman boxers are prone to ventricular tachycardia, which is a rapid abnormal heartbeat that occurs in the ventricles. Sinus node weakness syndrome is an anomaly that affects the SA node: it is most common in miniature schnauzers, dachshunds, cocker spaniels and West Highland White Terriers. Spaniels, German Shepherds and Labrador Retrievers are prone to certain types of heart block.
The prognosis (prognosis) for animals with cardiac arrhythmia depends on the type of arrhythmia, the main cause of the arrhythmia, as well as the type and extent of any existing heart disease. In dogs with congestive heart failure, the prognosis is poor.
What to watch
- Slow heart rate
- Fast heart rate
- Unstable Heart Rate
- Labored breathing
- Lack of appetite
Diagnosis of heart arrhythmias in dogs
A blood test, including a complete blood test and biochemical profile, should be performed to detect any major abnormalities. Some dogs may be anemic, have an increased number of white blood cells, or have organ dysfunction. Some diseases, such as hypothyroidism, can cause heart arrhythmias.
Cardiac arrhythmias are diagnosed using an electrocardiogram (ECG, ECG). The type of arrhythmia can be diagnosed using an ECG oscilloscope or a trace printout.
A chest x-ray (radiography) can help determine the presence of heart failure or heart failure.
An ultrasound of the heart (echocardiogram) is sometimes performed to determine the assessment of cardiac function and to detect any underlying heart disease.
Treatment of cardiac arrhythmias in dogs
Treatment depends on the severity of the arrhythmia and the presence of any underlying disease. There are various cardiac arrhythmias, and each is managed differently. Some of them are serious and require treatment or even electric shock treatment. Others are harmless and require no treatment at all.
In addition to treating cardiac arrhythmias, any underlying heart disease or other disease should also be considered.
Home Care and Prevention
There is no home care for a heart rhythm disorder, except that you must take any medications that your vet prescribes. If you suspect your dog has an abnormal heart rhythm or rhythm, you should immediately contact your veterinarian.
Cardiac arrhythmias are difficult to prevent, but early diagnosis and treatment of predisposing causes may reduce the risk of arrhythmias.
Detailed information about canine arrhythmias
Normal heart rhythms begin in the sinoatrial (SA or sinus) node, which is located in the right upper chamber (atrium) of the heart. While sinus abnormalities are usually caused by a systemic disorder, such as hypo or hyperthyroidism, primary sinus disease is common and can lead to a type of arrhythmia known as sinus syndrome. Other arrhythmias may occur that occur outside the SA node. One of the most serious of these is atrial fibrillation. Ventricular arrhythmias include premature ventricular contractions and ventricular tachycardia. More serious arrhythmias sometimes lead to cardiac decompensation and acute or chronic heart failure. Some arrhythmias are exacerbated before fibrillation and, ultimately, without any heartbeat (asystole).
A cardiac arrhythmia can lead to a very slow heartbeat (potentially just as slow at 40 beats per minute), called bradycardia; very fast heartbeat (potentially more than 200 beats per minute in a dog), called tachycardia; or irregular heartbeat. Different types of arrhythmias can occur. Here are some of the most common:
- Atrial fibrillation
- Atrial tachycardia
- Ventricular escape rhythm
- Ventricular premature complex
- Ventricular tachycardia
- Ventricular fibrillation
- First degree heart block
- Second degree heart block
- Third degree heart block
Often, cardiac arrhythmias are associated with underlying heart disease, such as dilated cardiomyopathy, congestive heart failure, or congenital heart defects. In addition, various other diseases or events can cause heart rhythm disorders, including:
- Hypothyroidism (with active thyroid)
- Chronic lung disease
- Overdose of certain medications such as digoxin, drugs, xylazine
- Introduction of anesthetics
- High or low blood potassium levels
- Heart tumors
- Toxicity such as chocolate poisoning
- Hypoadrenocorticism (Addison’s Disease – Adrenal Disease)
- Urinary Obstruction
- Lyme disease
- Inhalation of smoke
- Head injury
- Low blood pressure (hypotension)
- Gastric dilated volvul
- Spleen diseases
- Severe infections
Cardiac arrhythmias are often detected during physical examination. Your vet will listen to your dog’s heart with a stethoscope to determine if his heart rate is too slow, too fast, or unstable. If an arrhythmia is detected or suspected, this is confirmed by an electrocardiogram (ECG, ECG). Your dog will be located on the right side, and clamps or gaskets will be attached to its arms and legs. This procedure is painless. Then the ECG is turned on and the electrical activity of the heart is monitored. Tracing is checked to determine heart rate and rhythm.