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Noninvasive determination of atrial fibrillation cycle length by atrial colour tissue D oppler imaging in horses
Author(s) -
Decloedt A.,
Clercq D.,
Vekens N.,
Verheyen T.,
Loon G.
Publication year - 2014
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/evj.12108
Subject(s) - parasternal line , medicine , cardiology , atrial fibrillation , atrial flutter , cardioversion , intracardiac injection
Summary Reasons for performing study Atrial fibrillation cycle length ( AFCL ) is an indicator of atrial electrical remodelling during atrial fibrillation ( AF ). Objectives To compare AFCL measured invasively from an intra‐atrial electrogram ( AFCL EGM ) with AFCL measured noninvasively by atrial colour tissue D oppler imaging ( AFCL TDI ). Study design Prospective descriptive clinical study. Methods 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 EGM was measured from an intracardiac electrogram using a bipolar sensing/pacing electrode inserted into the right atrium. The AFCL TDI 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 EGM and AFCL TDI from the 5 regions were compared using a one‐way repeated‐measures ANOVA with B onferroni correction for multiple comparisons and calculation of the B land‐ A ltman mean bias and limits of agreement of AFCL EGM and AFCL TDI . Results The AFCL EGM was 161 ± 18 ms in 29 AF episodes. Two horses showed atrial flutter and had an AFCL EGM of 244 and 324 ms. The mean bias between AFCL TDI and AFCL EGM ranged from ‐18 to +9 ms depending on the atrial wall region. The AFCL TDI 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). Conclusions Tissue D oppler 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.