Perego Manuela, Maffei Alessandra, Cavallini Damiano, Santilli Roberto
Clinica Veterinaria Malpensa Anicura, Samarate, Italy.
Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
Front Vet Sci. 2025 May 20;12:1579951. doi: 10.3389/fvets.2025.1579951. eCollection 2025.
The differentiation between ventricular tachycardias (VT) and supraventricular tachycardias (SVT) with bundle branch block (BBB) is clinically challenging. The aim of the study was to define by the 12-lead-electrocardiogram the QRS complex morphology in monomorphic VT (MVT) and in BBB.
Twelve-lead-electrocardiograms were blindly retrospectively analyzed and categorized in four groups: sinus rhythm with left bundle branch block (SR-LBBB), sinus rhythm with right bundle branch block (SR-RBBB), MVT with RBBB configuration (MVT-RBBB), MVT with LBBB configuration (MVT-LBBB). Measurements were not normally distributed, and they were normalized by Box-Cox transformation. Repeated-measures linear mixed-effects models were constructed according to the 3 measurements performed.
A total of 103 12-lead-electrocardiograms were retrospectively analyzed: 18 SR-RBBB, 18 SR-LBBB, 33 MVT-RBBB, 34 MVT-LBBB. Limb leads concordance was found in 100% of SR-RBBB, 100% of SR-LBBB, 54.5% of MVT-RBBB, 70.6% of MVT-LBBB. Precordial leads discordance was present in 100% of SR-RBBB, 100% of SR-LBBB, 78.8% of MVT-RBBB, 88.2% of MVT-LBBB. The transition point was located at V1-V2 in 100% of SR-RBBB, 100% of SR-LBBB, 50.5% of MVT-RBBB and 71.5% of MVT-LBBB. Positive V1 with M shape morphology was detected in 100% of SR-RBBB and 12% of MVT-RBBB. The mean electrical axis on the frontal plane was -108.15° (-118.29 / -101.52) in RSSR-RBBB, 75.42° (71.78-80.46) in RSSR -LBBB, -93.46° (-102.75/-78.49) in MVT-RBBB and 82.27° (76.85-88.95) in MVT-LBBB.
In case of inability to identify signs of atrioventricular dissociation, the presence of standard limb leads discordance, precordial leads concordance or discordance with transition point other than V1-V2, left limb leads and left precordial leads discordance, aVR and V1 discordance and absence of M shape configuration of the QRS complex in lead V1 is likely to be MVT.
室性心动过速（VT）与伴有束支传导阻滞（BBB）的室上性心动过速（SVT）之间的鉴别在临床上具有挑战性。本研究的目的是通过12导联心电图确定单形性室性心动过速（MVT）和束支传导阻滞时QRS波群的形态。
对12导联心电图进行盲法回顾性分析，并分为四组：窦性心律伴左束支传导阻滞（SR-LBBB）、窦性心律伴右束支传导阻滞（SR-RBBB）、右束支传导阻滞图形的单形性室性心动过速（MVT-RBBB）、左束支传导阻滞图形的单形性室性心动过速（MVT-LBBB）。测量值不呈正态分布，通过Box-Cox变换进行标准化。根据进行的3项测量构建重复测量线性混合效应模型。
共回顾性分析了103份12导联心电图：18份SR-RBBB、18份SR-LBBB、33份MVT-RBBB、34份MVT-LBBB。100%的SR-RBBB、100%的SR-LBBB、54.5%的MVT-RBBB、70.6%的MVT-LBBB出现肢体导联一致性。100%的SR-RBBB、100%的SR-LBBB、78.8%的MVT-RBBB、88.2%的MVT-LBBB出现胸前导联不一致。100%的SR-RBBB、100%的SR-LBBB、50.5%的MVT-RBBB和71.5%的MVT-LBBB的移行点位于V1-V2。100%的SR-RBBB和12%的MVT-RBBB检测到V1导联呈M形的正向波。额面平均电轴在SR-RBBB中为-108.15°（-118.29 / -101.52），在SR-LBBB中为75.42°（71.78 - 80.46），在MVT-RBBB中为-93.46°（-102.75 / -78.49），在MVT-LBBB中为82.27°（76.85 - 88.95）。
在无法识别房室分离迹象的情况下，出现标准肢体导联不一致、胸前导联一致性或与V1-V2以外的移行点不一致、左上肢导联和左胸前导联不一致、aVR和V1不一致以及V1导联QRS波群无M形图形，很可能是室性心动过速。
