Noninvasive determination of atrial fibrillation cycle length by atrial colour tissue Doppler imaging in horses. (30th August 2013)

• Record Type: Journal Article
• Authors: Decloedt, A.; de, D.; van der, N.; Verheyen, T.; van, G.
• Is Part Of: Equine veterinary journal. Volume 46:Number 2(2014:Mar.)
• Page Start: 174
• Page End: 179
• Publication Date: 2013-08-30
• Subjects: Horses -- Diseases -- Periodicals; 636.108905
• DOI: 10.1111/evj.12108
• Languages: English
• ISSNs: 0425-1644

Abstract

<abstract abstract-type="main"> <title>Summary</title> <sec id="evj12108-sec-0001" sec-type="section"> <title>Reasons for performing study</title> <p>Atrial fibrillation cycle length (AFCL) is an indicator of atrial electrical remodelling during atrial fibrillation (AF).</p> </sec> <sec id="evj12108-sec-0002" sec-type="section"> <title>Objectives</title> <p>To compare AFCL measured invasively from an intra‐atrial electrogram (AFCL<sub>EGM</sub>) with AFCL measured noninvasively by atrial colour tissue Doppler imaging (AFCL<sub>TDI</sub>).</p> </sec> <sec id="evj12108-sec-0003" sec-type="section"> <title>Study design</title> <p>Prospective descriptive clinical study.</p> </sec> <sec id="evj12108-sec-0004" sec-type="section"> <title>Methods</title> <p>Measurements were performed in 31 episodes of AF or flutter in 29 horses (588 ± 61 kg bwt, 9 ± 3 years old) admitted for transvenous electrical cardioversion. The AFCL<sub>EGM</sub> was measured from an intracardiac electrogram using a bipolar sensing/pacing electrode inserted into the right atrium. The AFCL<sub>TDI</sub> was measured from atrial colour tissue velocity curves in the following 5 regions: 1) left atrial free wall from a right parasternal 4‐chamber view, 2) left atrial free wall from a short‐axis view, 3) left atrial free wall from a left parasternal long‐axis view, 4) interatrial septum, and 5) right atrial dorsal wall near the tuberculum intervenosum. The AFCL<sub>EGM</sub> and AFCL<sub>TDI</sub> from the 5 regions were compared using a one‐way repeated‐measures ANOVA with Bonferroni correction for multiple comparisons and calculation of the Bland‐Altman mean bias and limits of agreement of AFCL<sub>EGM</sub> and AFCL<sub>TDI</sub>.</p> </sec> <sec id="evj12108-sec-0005" sec-type="section"> <title>Results</title> <p>The AFCL<sub>EGM</sub> was 161 ± 18 ms in 29 AF episodes. Two horses showed atrial flutter and had an AFCL<sub>EGM</sub> of 244 and 324 ms. The mean bias between AFCL<sub>TDI</sub> and AFCL<sub>EGM</sub> ranged from ‐18 to +9 ms depending on the atrial wall region. The AFCL<sub>TDI</sub> was significantly shorter in the left atrial free wall from the right parasternal 4‐chamber view and short‐axis view than in the other regions (P<0.001).</p> </sec> <sec id="evj12108-sec-0006" sec-type="section"> <title>Conclusions</title> <p>Tissue Doppler imaging allows noninvasive measurement of AFCL in horses with AF and is able to identify spatial differences within the equine atria. Atrial fibrillation cycle length is an indicator of atrial electrical remodelling and is an important parameter to study AF pathophysiology or the effect of antiarrhythmic drugs.</p> </sec> </abstract>