Right atrial-related structures in horses of interest during electrophysiological studies.
Authors: Vernemmen Ingrid, Vera Lisse, Van Steenkiste Glenn, Deserranno Bram, Muylle Sofie, Decloedt Annelies, van Loon Gunther
Journal: Equine veterinary journal
Summary
# Editorial Summary: Right Atrial Anatomy for Equine Electrophysiology Catheter-based electrophysiological interventions remain underdeveloped in equine practice largely because detailed anatomical knowledge of the equine heart is lacking, yet arrhythmias are a significant clinical problem in horses. Vernemmen and colleagues conducted a post-mortem examination of 21 Warmblood hearts to characterise key electrophysiologically relevant structures—the coronary sinus, great cardiac vein, and oval fossa—recording their dimensions and anatomical variations in relation to bodyweight and aortic diameter. The coronary sinus ostium was partially obscured by a Thebesian valve in 43% of specimens, whilst the great cardiac vein contained a median of 6.5 valves (range 4–9), and several parameters including oval fossa dimensions showed significant positive correlation with bodyweight and aortic diameter. These reference measurements provide essential baseline data for developing and refining minimally invasive intracardiac procedures in horses, though practitioners should recognise that measurements were obtained ex vivo and therefore do not account for dynamic changes during the cardiac cycle, and that findings are specific to Warmblood horses, potentially limiting applicability to other breeds. The next logical step involves identifying appropriate imaging modalities capable of reliably identifying these landmarks in living horses during procedural guidance.
Read the full abstract on PubMed
Practical Takeaways
- •This anatomical reference data is essential for veterinarians developing catheter-based electrophysiological interventions and ablation procedures in horses with arrhythmias
- •Expect anatomical variation based on horse size and breed; these measurements apply specifically to Warmblood horses and may not translate directly to other breeds
- •Advanced imaging techniques will be needed to visualize these structures in living horses before attempting minimally invasive intracardiac procedures clinically
Key Findings
- •Median dimensions of coronary sinus, great cardiac vein, and oval fossa were established in Warmblood horses for electrophysiological reference
- •A Thebesian valve partially covering the coronary sinus ostium was present in 43% (9/21) of hearts examined
- •Great cardiac vein contained a median of 6.5 valves (range 4-9) that may impact catheter navigation
- •Oval fossa dimensions and great cardiac vein length showed significant positive correlation with bodyweight and aortic diameter