A 1.5-year-old, female-spayed mix-breed dog was presented with recurrent episodes of shaking and excessive panting attributed to drug-refractory ventricular arrhythmia (VA) characterized predominantly by incessant periods of ventricular bigeminy. The VA had a narrow QRS morphology, suggestive of an origin near the His bundle or fascicular system. Diagnostic evaluation found no structural heart disease or underlying etiology. Three-dimensional electroanatomic mapping and radiofrequency catheter ablation were pursued. Voltage mapping demonstrated normal bi-ventricular voltage (≥1.5 mV) without any fractionated or multicomponent electrograms, indicating the absence of ventricular myocardial scar. Pace mapping identified an endocardial origin of the VA at the basal anterior septum of the left ventricle, distal to the His bundle and near the left bundle branch. Two ablation lesions were delivered to this site, and a left bundle branch block was temporarily induced. The dog recovered uneventfully. One month later, the owners reported a remarkable improvement in clinical signs, and follow-up 48-h Holter monitor found complete resolution of VA.

一只 1.5 岁的雌性绝育混种狗出现反复发作的颤抖和过度喘气，这归因于药物难治性室性心律失常 (VA)，其主要特征是室性二联律的持续时间。VA 具有狭窄的 QRS 形态，提示其起源于希氏束或束状系统附近。诊断评估未发现结构性心脏病或潜在病因。进行了三维电解剖标测和射频导管消融。电压映射显示正常的双心室电压 (≥1.5 mV)，没有任何分次或多分量电图，表明没有心室心肌瘢痕。起搏标测确定了左心室基底前间隔处 VA 的心内膜起源，希氏束远端和左束支附近。将两个消融病灶送至该部位，暂时诱导左束支传导阻滞。狗平安无事地康复了。一个月后，业主报告临床症状显着改善，后续 48 小时动态心电图监测发现 VA 完全消退。