Many arrhythmias in horses are normal, and a few are dangerous. The exam tests whether you can tell a vagally mediated second-degree AV block from atrial fibrillation (AF), and whether you know that AF in a performance horse is treated by conversion to sinus rhythm, usually with quinidine.
Key facts
Cardiac arrhythmia at a glance- Species and system: horse; cardiovascular.
- Common and often normal at rest: second-degree AV block, sinus arrhythmia and sinus pauses, from high vagal tone. They should disappear with exercise or excitement (McGurrin 2015).
- AF: a common arrhythmia in horses; it usually occurs without underlying heart disease, and many horses show no signs at rest or in moderate exercise (MSD). It is the most common arrhythmia causing poor performance (Kjeldsen 2022).
- Conversion drug: quinidine sulfate is the drug of choice in horses (MSD); transvenous electrical cardioversion (TVEC) is an alternative.
- Dangerous rhythms: ventricular tachycardia (VT), frequent or exercise-associated ventricular premature complexes, and third-degree AV block.
- Zoonotic: no.
What's inside
12 sections in the full guide- Key facts
- How the NAVLE tests this
- Cause and pathophysiology
- Clinical signs
- Diagnosis
- Differential diagnoses
- Treatment and management
- Prognosis
- Putting it together in practice
- Quick review
- Test yourself
- References
The full guide also has 5 tables, 1 figure, 3 self-test questions and 10 references, available to NAVLE members.
Read the full study guide
The full guide is part of every NAVLE plan, with diagnosis and treatment tables, figures, a quick review and self-test questions. Start a free trial to try the question bank, or log in if you are already a member.