We’ve all been there. Your car starts with a strange hitch every day for a week, but the morning you visit the mechanic it fires right up. Your toddler coughs up a storm all night long, but seems right as rain in the pediatrician’s exam room. Your dog has an abnormal heart rhythm (arrhythmia) during his wellness exam, but at a follow up visit your vet can’t detect any abnormalities….

Your dog’s heart is an incredible machine! It beats because an electrical impulse travels along a set path through a collection of “nodes”, causing the heart muscle to contract in a particular place at a particular time. These contractions of the heart muscle cause blood to pump through each of the four chambers of the heart, and out into the body. When this electrical impulse is disturbed, your dog may experience symptoms of an arrhythmia. These can include lethargy, exercise intolerance, low blood pressure, or even fainting/collapse (syncope).

The term “cardiac arrhythmia” (an abnormal heartbeat) can refer to a heart rate that is too slow, a heart rate that is too fast, or a rhythm that “skips beats”. Relatively common in dogs, cardiac arrhythmias are not always cause for concern. However, some arrhythmias can indicate serious underlying heart disease, such as Dilated Cardiomyopathy  or Sick Sinus Syndrome. Certain breeds, including Boxers, Dobermans, and Schnauzers, are more prone to dangerous arrhythmias than others.

For aid in diagnosing cardiac arrhythmias, your veterinary cardiologist may recommend a 24-hour Holter monitor. Whereas a typical ECG records approximately 2 minutes of heart rhythm, the wearable Holter device records a full 24-48 hours of information. This gives your dog’s medical team a more complete picture of the typical heart rhythm as your pet goes about their normal daily activities. The results of Holter monitoring may help your veterinarian detect dangerous arrhythmias, which are not always obvious through echocardiography (ultrasound of the heart) or standard ECG monitoring.

The Holter monitor can help your veterinarian:

  • Record heart rate variability during normal activity, exercise, and rest or sleep.
  • Diagnose the type of arrhythmia in order to determine the correct treatment.
  • Determine how well prescribed medications are correcting your pet’s arrhythmia.

The Holter is a simple, non-invasive device about the size of a deck of cards. It attaches to your pet’s chest with either 5 or 7 wire leads, and sticky ECG conductor pads. To ensure the leads are reliably recording your pet’s heart rate, your veterinary team may shave your pet’s chest (underneath the armpits) to establish skin contact, though shaving for short haired dogs is not always necessary. Often your pet will get to wear home a trendy lycra or spandex vest, which covers the electrical leads and holds the monitor in place. Your dog should be able to move comfortably while wearing the monitor, and most dogs forget they are wearing them.

conductor pasAt Cardiology Northwest, we give you the option of removing the monitor at home, or bringing your dog back to our office so our staff can remove it. The sticky ECG pads can be easily removed with an adhesive remover, such as Detachol. We strive to call you with results 5-7 days after the monitor is returned to our office, and will make recommendations for medical management and follow up care at that time.

Holter monitoring can be an invaluable tool in diagnosing and managing your pet’s cardiac arrhythmia! If you have questions about how preventative or diagnostic holtering may benefit your pet’s health plan, contact our office for more information.