Cardiology
Dr. van Loon's team continues its research in equine cardiology. In this study, an adaptation to the traditional 12-lead resting ECG recording technique, to determine the optimal positioning of Einthoven's triangle in horses, was investigated. The study aims were to standardise ECG acquisition methodology and improve arrhythmia diagnosis.
Eleven electrodes were placed in a multiple triangular horizontal base configuration in the transverse plane, around the thorax of seventy-two healthy Warmblood horses (aged 3–20 years). Electrocardiographic signal processing and analysis was performed using filtering, R peak detection, median complex generation, principal component analysis (PCA) and Euclidean distance measures. The “Delta (Δ) base-down triangular configuration” proved to be the most informative, in terms of amplitude size and diagnostic potential. The transverse positioning of the Delta configuration supports its suitability for 12-lead ECG recording systems and vectorcardiography in an orthogonal framework. Using the Delta configuration as the standardised approach could significantly improve the comparability between ECG data in equine cardiology.
https://doi.org/10.1111/jvim.17179
A further article from Dr. van Loon's team. This study investigated the feasibility of using transthoracic echocardiography to guide multiple electrophysiology catheters to strategic positions within the heart in horses, with the aim of improving minimally invasive arrhythmia characterisation. Eight healthy adult horses each underwent two procedures: catheter placement in the right heart during standing sedation and catheter placement in the left heart under general anaesthesia. Right-parasternal transthoracic echocardiography and 3D electro-anatomical mapping were used to guide the multiple catheters along their trajectory, to the predetermined positions within the heart. Catheter positioning was predominantly successfully achieved in the right heart and left ventricle, whereas positioning in the left atrium and pulmonary veins proved more challenging. This minimally invasive ultrasound-guided multiple catheterisation method may be a potential alternative to 3D mapping for arrhythmia diagnosis.
https://doi.org/10.1111/jvim.17156
This study by Gunter van Loon's team evaluated the clinical outcomes and follow-up of transthoracic echocardiography-guided transseptal puncture (TSP) in horses. Traditionally limited to right-atrial access, TSP enables left-atrial access while avoiding arterial approaches. The procedure was performed in 11 healthy horses under general anesthesia, with serum cardiac troponin I levels monitored pre- and post-procedure. TSP was successful in all cases, with a median duration of 22 minutes. Balloon dilation was required in four horses. Iatrogenic atrial septal defect (iASD) closure was tracked weekly via transthoracic and intracardiac echocardiography for at least four weeks. Atrial arrhythmias were observed in 9 of 11 horses, including atrial tachycardia, fibrillation, and premature depolarisations. Troponin I levels increased post-TSP but remained within reference ranges in most horses. Spontaneous iASD closure occurred within a median of 14 days. These findings confirm the safety of TSP and its potential for diagnosing and managing left-sided arrhythmias in equine patients.
https://doi.org/10.1111/jvim.17158