Open AccessAtrial Premature Depolarization‐Induced Changes in QRS and T Wave Morphology on Resting Electrocardiograms in Horses
Author(s) -
Broux B.,
De Clercq D.,
Decloedt A.,
Van Der Vekens N.,
Verheyen T.,
Ven S.,
Pardon B.,
Loon G.
Publication year - 2016
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.13957
Subject(s) - medicine , qrs complex , cardiology , electrocardiography , sinus rhythm , pr interval , heart rate , atrial fibrillation , blood pressure
Background The electrocardiographic differentiation between atrial ( APD s) and ventricular ( VPD s) premature depolarizations is important. P wave prematurity and normal QRS and T wave morphology generally are used as discriminating criteria for APD s. Hypothesis/Objectives The aim of this study was to determine whether P, Q, R, S, and T wave amplitude, PQ interval, QRS and P wave duration and P and T wave morphology differ between APD s and sinus beats. To determine the relationship between the RR coupling interval and the change in S wave amplitude between sinus beats and APD s. Methods Case–control study. From a modified base‐apex configuration of 30 horses with APD s at rest, sinus beat and APD associated preceding RR interval, P, PQ and QRS duration and P, R, S, and T wave amplitudes were measured. Linear mixed models and logistic regression were used to determine the effect of APD s on the ECG variables studied. Results In comparison to sinus beats, APD s were associated with a significant ( P < .001) change in P amplitude (−0.03 ± 0.01 mV) and increase in S (0.20 ± 0.02 mV) and T (0.08 ± 0.03 mV) amplitude. PQ (−20.3 ± 5.2 ms) and RR (−519 ± 14 ms) interval and P duration (−21.1 ± 3.0 ms) decreased ( P < .001). APD s were significantly associated with a singular positive P wave ( OR : 11.0, P < .001) and were more likely to have a monophasic positive T wave ( OR : 9.2, P < .001). A smaller RR coupling interval was associated with an increased relative difference in S amplitude ( P < .01). Conclusions Atrial premature depolarizations may lead to changes in QRS and T wave morphology. Knowledge of these changes is important to avoid interpreting certain APD s as VPD s.