Electrocardiographic findings in healthy Cavalier King Charles Spaniels, Pugs, and English Bulldogs

Abstract

OBJECTIVE To describe the ECG findings in 3 different canine brachycephalic breeds: the Cavalier King Charles Spaniel, the Pug, and the English Bulldog (EB). ANIMALS 135 healthy dogs (50 Cavalier King Charles Spaniels, 50 Pugs, and 35 EBs). PROCEDURES Medical records were retrospectively reviewed to identify healthy dogs ≥ 1 year old that had undergone an ECG. The Mann-Whitney U test or the Student t test were used to compare continuous variables between male and female dogs, whereas the χ2 test was used for categorical variables. Spearman correlation coefficients between ECG measurements and age and body weight were also calculated in the case of continuous variables, whereas the Kruskal-Wallis test was used for categorical ones. RESULTS Electrocardiographic parameters of healthy Cavalier King Charles Spaniels overall fitted with traditional reference intervals cited in textbooks; in contrast, 28% of Pugs and 20% of EBs showed a shift of the QRS-complex mean electrical axis (QRS-MEA). In Pugs and EBs, the mean/median QRS-MEA value was 56° (from 0° to 100°) and 59° (from 20° to 100°), respectively. All axis shifts were left shifts (in Pugs, from 0° to 34°; in EBs, 20° to 39°). Only a few meaningful differences were found when comparing ECG variables between males and females. Similarly, only 1 statistically significant correlation was found between ECG parameters and age and body weight. CLINICAL RELEVANCE Healthy Pugs and EBs present a trend to a left shift of the QRS-MEA. This should be considered when interpreting ECG tracings in these breeds.

Evaluating the accuracy of a six‐lead smartphone‐based electrocardiographic device compared with standard electrocardiography in brachymorphic dogs

“…Specifically, according to both ECG devices, approximately 40% of dogs had a left shift of this parameter. This result is in line with two previous investigations of the ECG features of healthy FBs and EBs that documented a left shift of the QRS complex MEA in 30% of FB 26 and 20% of EBs, 56 respectively, and assumed that such a finding was a physiological characteristic of Bulldogs related to their particular chest conformation rather than a true disturbance of ventricular conduction 26,56 . From a clinical point of view, this result suggests that this six‐lead s‐ECG may be able to detect breed‐related ECG peculiarities similarly to the st‐ECG.…”

“…This result is in line with two previous investigations of the ECG features of healthy FBs and EBs that documented a left shift of the QRS complex MEA in 30% of FB 26 and 20% of EBs, 56 respectively, and assumed that such a finding was a physiological characteristic of Bulldogs related to their particular chest conformation rather than a true disturbance of ventricular conduction. 26,56 From a clinical point of view, this result suggests that this sixlead s-ECG may be able to detect breed-related ECG peculiarities similarly to the st-ECG. However, further studies are needed to demonstrate whether this device is also capable of identifying further breed-related peculiarities in breeds other than Bulldogs.…”