Ventricular Rhythms

Observational Study on Cardiac Activity in Rescue Dogs with Holter and Electrocardiogram Methodologies during a Simulated Search Activity

“…An interesting result has been observed during our Holter examination of a 7-year-old Labrador with an ectopic beat. Ventricular ectopic beats are caused by spontaneous depolarization of an ectopic pacemaker located anywhere in the ventricular specialized conduction system or working myocardium [ 14 ]. If the beat originates from the working myocardium, impulse conduction will occur via cell-to-cell depolarization, which is a slow process and will depolarize the ventricles asynchronously.…”

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

“…Then, the HR in beats per minute (bpm) was calculated by determining the number of QRS complexes in a 3‐second interval and multiplying this number by 20. For the purpose of this study, the classification of the heart rhythms/rate included 36–40 : sinus bradycardia: four or more successive sinus complexes at an HR less than 60 bpm; normal sinus rhythm: four or more successive sinus complexes at an HR of 60−180 bpm; sinus tachycardia: four or more successive sinus complexes at an HR greater than 180 bpm; supraventricular premature complexes (SvPC): a premature normal‐appearing QRS complex not preceded by any P wave or conducted by a P wave with abnormal morphology; supraventricular tachycardia: three or more SvPCs at an HR greater than 160 bpm; atrial fibrillation: replacement of isoelectric baseline and sinus P waves by sequential less‐defined deflections varying in amplitude, morphology and cycle length, associated with normal‐appearing QRS complexes and irregular ventricular rhythm; ventricular premature complex (VPC): a premature wide and bizarre looking QRS complex, not associated with a P wave; accelerated idioventricular rhythm: three or more VPCs at an HR of 60−180 bpm; ventricular tachycardia: three or more VPCs at an HR greater than 180 bpm; second‐degree atrioventricular block (AVB): a P wave without an associated QRS complex; third‐degree AVB: evidence of P waves dissociated from QRS complexes with a ventricular rate less than 60 bpm. …”

“…Moreover, SvPCs and VPCs were also characterised as follows 38 : couplet: two consecutive SvPCs/VPCs; triplet: three consecutive SvPCs/VPCs; bigeminy: an SvPC/PVC following every sinus beat. …”

“…Then, the HR in beats per minute (bpm) was calculated by determining the number of QRS complexes in a 3-second interval and multiplying this number by 20. For the purpose of this study, the classification of the heart rhythms/rate included [36][37][38][39][40] :…”