Introduction: Ventricular rhythm disturbances are a common pathology in human and veterinary medicine. In humans, the algorithmic approach is used to differentiate wide QRS complex tachycardia. The most commonly used are the aVR and Brugada algorithms as well as the ventricular tachycardia (VT) score developed by Jastrzębski and coworkers. In veterinary medicine, no such algorithms are available and the only parameter used to describe VT abnormalities is the duration of the QRS complexes. The aim of this analysis was determining whether human medicine algorithms for VT are applicable in veterinary medicine to differentiate wide QRS complex tachycardia in dogs.
Material and Methods: A retrospective analysis was performed on 11 dogs of both sexes and various breeds and age diagnosed with VT. The diagnosis was based on ambulatory ECG, further established based on the reaction to lidocaine or adenosine or an invasive electrophysiological study.
Results: Of the 11 tracings passed through the aVR algorithm, 10 met the VT criteria. The most common criterion was the Vi/Vt ratio (8 out of 11 tracings). Based on the VT score, seven out of eight dogs had a high probability of VT.
Conclusion: Retrospective analysis of ECGs by aVR and VT score indicates that the applied algorithms may be useful in differentiating wide QRS complex tachycardia as a quick, easy, and non-invasive alternative to cardiac electrophysiology.
1. Brugada P., Brugada J., Mont L., Smeets J., Andries E.W.: A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex. Circulation 1991, 83, 1649–1659.
2. de Bakker J.M., van Capelle F.J., Janse M.J., Wilde A.A., Coronel R., Becker A.E., Dingemans K.P., van Hemel N.M., Hauer R.N.: Reentry as a cause of ventricular tachycardia in patients with chronic ischemic heart disease: electrophysiologic and anatomic correlation. Circulation 1988, 77, 589–606.
3. Fox P.R., Sisson D., Moise N.S.: Textbook of Canine and Feline Cardiology, W.B. Saunders, Philadelphia, 1999.
4. Gomes J.A., Dhatt M.S., Damato A.N., Akhtar M., Holder C.A.: Incidence, determinants, and significance of fixed retrograde conduction in the region of the atrioventricular node. Evidence for retrograde atrioventricular nodal bypass tracts. Am J Cardiol 1979, 44, 1089–1098.
6. Jastrzębski M.: A practical approach to differentiating wide QRS complex tachycardia (Praktyczne podejście do różnicowania częstoskurczów z szerokimi zespołami QRS). Przewodnik Lek 2009, 12, 20–29.
7. Jastrzębski M., Sasaki K., Kukla P., Fijorek K., Stec S., Czarnecka D.: The ventricular tachycardia score: a novel approach to electrocardiographic diagnosis of ventricular tachycardia. Europace 2016, 18, 578–584.
8. Josephson M.E.: Clinical cardiac electrophysiology. Electrophysiologic investigation: general aspects. Techniques and interpretations. Sinus node function. Lippincott Williams & Wilkins, Philadelphia, 2002.
9. Noszczyk-Nowak A., Michałek M., Kałuża E., Cepiel A., Pasławska U.: Prevalence of arrhythmias in dogs examined between 2008 and 2014. J Vet Res 2017, 61, 103–110.
10. Sheldon S.H., Gard J.J., Asirvatham S.J.: Premature ventricular contractions and non-sustained ventricular tachycardia: association with sudden cardiac death, risk stratification, and management strategies. Indian Pacing Electrophysiol J 2010, 10, 357–371.
11. Tilley L.P., Smith F.W.K. Jr.: Electrocardiography. In: Manual of Canine and Feline Cardiology, edited by Tilley L.P., Smith Jr F.W.K., Oyama M.A., Sleeper M.M., Elsevier, St Louis, 2016, p. 56.
12. Vereckei A., Duray G., Szénási G., Altemose G.T., Miller J.M.: New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachycardia. Heart Rhythm 2008, 5, 89–98.