TY - JOUR

T1 - Detection of atrial fibrillation with implantable loop recorders in horses

AU - Buhl, Rikke

AU - Hesselkilde, Eva Melis

AU - Carstensen, Helena

AU - Fenner, Merle Frederike

AU - Jespersen, Thomas

AU - Tfelt-Hansen, Jacob

AU - Sattler, Stefan Michael

N1 - This article is protected by copyright. All rights reserved.

PY - 2021

Y1 - 2021

N2 - BACKGROUND: Cardiac arrhythmias in horses are diagnosed by auscultation or electrocardiogram (ECG), which results in a low sensitivity for detecting arrhythmias that occur sporadically. Implantable loop recorders (ILRs) are small ECG devices placed subcutaneously, to automatically detect arrhythmias in human patients.OBJECTIVES: To test ILRs ability to detect atrial fibrillation (AF) in horses. Further, we hypothesised that anatomical location of the implant site might influence signal quality. Signal quality was evaluated both during exercise and over time.STUDY DESIGN: Experimental study.METHODS: In five Standardbred mares, eleven ILRs were implanted subcutaneously in up to three different positions (Front: pectoral region, Left-6: sixth left intercostal space, Ventral: xiphoid region) and AF induced. The R and T wave amplitudes were measured in all positions over time during AF. AF burden automatically registered by the ILRs over a 2-month period were compared with selected Holter ECG recordings.RESULTS: All three positions had stable R and T wave amplitudes during the study period and were of sufficient quality to allow AF detection at rest. The position Left-6 showed significantly higher R and T wave amplitudes compared to the other positions. During submaximal exercise only the Left-6 position was able to record ECG signals of diagnostic quality. No position yielded diagnostic signals at maximum exercise due to artefacts.MAIN LIMITATIONS: Few horses and ILRs included and no spontaneous AF episodes were studied.CONCLUSIONS: This preliminary study indicates that ILRs can be used for AF detection in horses, but the anatomical location is important for optimal ECG quality. Despite insufficient quality during exercise, ILRs were suitable for AF detection at rest. Therefore, the ILR may be a valuable diagnostic tool for detecting paroxysmal AF in horses.

AB - BACKGROUND: Cardiac arrhythmias in horses are diagnosed by auscultation or electrocardiogram (ECG), which results in a low sensitivity for detecting arrhythmias that occur sporadically. Implantable loop recorders (ILRs) are small ECG devices placed subcutaneously, to automatically detect arrhythmias in human patients.OBJECTIVES: To test ILRs ability to detect atrial fibrillation (AF) in horses. Further, we hypothesised that anatomical location of the implant site might influence signal quality. Signal quality was evaluated both during exercise and over time.STUDY DESIGN: Experimental study.METHODS: In five Standardbred mares, eleven ILRs were implanted subcutaneously in up to three different positions (Front: pectoral region, Left-6: sixth left intercostal space, Ventral: xiphoid region) and AF induced. The R and T wave amplitudes were measured in all positions over time during AF. AF burden automatically registered by the ILRs over a 2-month period were compared with selected Holter ECG recordings.RESULTS: All three positions had stable R and T wave amplitudes during the study period and were of sufficient quality to allow AF detection at rest. The position Left-6 showed significantly higher R and T wave amplitudes compared to the other positions. During submaximal exercise only the Left-6 position was able to record ECG signals of diagnostic quality. No position yielded diagnostic signals at maximum exercise due to artefacts.MAIN LIMITATIONS: Few horses and ILRs included and no spontaneous AF episodes were studied.CONCLUSIONS: This preliminary study indicates that ILRs can be used for AF detection in horses, but the anatomical location is important for optimal ECG quality. Despite insufficient quality during exercise, ILRs were suitable for AF detection at rest. Therefore, the ILR may be a valuable diagnostic tool for detecting paroxysmal AF in horses.

U2 - 10.1111/evj.13301

DO - 10.1111/evj.13301

M3 - Journal article

C2 - 32506470

VL - 53

SP - 397

EP - 403

JO - Equine Veterinary Journal

JF - Equine Veterinary Journal

SN - 0425-1644

IS - 2

ER -