Ventricular Fibrillation in Dogs
Ventricular fibrillation (V-Fib) is a disorder where the muscles of the heart’s ventricles start contracting in an erratic manner, causing them to quiver. This disorganized contraction can lead to the cessation of blood circulation within minutes, potentially resulting in fatality. While it can impact dogs of any age, it appears to be more prevalent in older dogs.
Symptoms and Types
- General illnesses linked to heart conditions
- Prior occurrences of irregular heart rhythms (cardiac arrhythmias)
- Sudden collapse
- Fatal outcome
Causes
- Lack of oxygen in inhaled gases, arterial blood, or tissues
- Obstruction of the aorta (aortic stenosis)
- Cardiac surgeries
- Reactions to medications (such as anesthetics, particularly fast-acting barbiturates, digoxin)
- Electric shocks
- Imbalances in electrolytes
- Hypothermia
- Myocarditis (inflammation of the heart muscle)
- Shock
Diagnosis
Unless there is an underlying infection, metabolic issue, or similar condition, routine laboratory test findings are typically normal. Nonetheless, your veterinarian will conduct an ECG (electrocardiogram) to detect V-Fib and other associated heart issues.
Treatment
This constitutes an emergency situation demanding prompt and assertive intervention. Without treatment, most dogs succumb within minutes. Often, electrical cardioversion is employed, utilizing an electrical defibrillator to administer small electrical shocks in order to restore normal heart rhythm. Initially, low-intensity shocks are administered; if the heart does not respond, the attending veterinarian may escalate the voltage.
In the absence of an electrical defibrillator, the veterinarian may opt for a precordial thump, involving a sharp blow to the chest wall over the heart with an open fist. Though seldom effective, it may represent the sole alternative.
Living and Management
After the dog’s heart has restored to a normal rhythm, it will need hospitalization for a few days to complete recovery. Regular follow-up appointments with the veterinarian will also be necessary for monitoring the dog’s progress, usually involving ECG and other diagnostic procedures.