Arrhythmias

Question 1

What are the most common forms of arrhythmias associated with heart disease in cats

Answer 1

Ventricular tachyarrhythmias (VPC)

Ventricular tachycardia (VT)

Question 2

Are healthy cats prone to ventricular arrhythmias

Answer 2

Ventricular arrhythmias appear to be common in healthy adult cats
- their frequency increases with age

Question 3

What would be your differentials for non-cardiac causes of arrhythmias

Answer 3

Non-cardiac causes of arrhythmias include:
- hyperthyroidism
- electrolytes abnormalities (i.e., calcium, potassium, magnesium disorders)
- anemia of any cause
- trauma
- neoplasia (primary or secondary, paraneoplastic syndrome)
- drug related (e.g., anesthetic, toxins)

Question 4

What are the clinical signs of life-threatening arrhythmias

Answer 4

Cats may not show any signs of abnormal cardiac rhythm if the rhythm does not disrupt cardiac output to a significant degree

As cardaic output becomes impaired, clinical signs may manifest as:
- depressed mentation
- weakness
- collapse
- dyspnea/tachypnea
- sudden death

Question 5

How different are ventricular and supra-ventricular arrhytmias on an ECG trace

Answer 5

Ventricular arrhythmias are characterized by wide, bizarre QRS complexes

Supraventricular arrhythmias are characterized by narrow (normal) QRS complexes