The aim of the study was to estimate prevalence of tricuspid dysplasia (TD) in dogs with respect to breed, age, sex, clinical signs, and echocardiographic findings and to compare this data with literature. TD was found in 15 dogs (6.5% of congenital cardiac disease) of 215 dogs with congenital heart defects. All dogs had right heart enlargement on thoracic radiographs, echocardiography, and electrocardiography. Doppler echocardiography revealed tricuspid valve regurgitation. Seven dogs presented no clinical symptoms to date. TD took the form of Ebstein anomaly in all Labrador Retrievers, one Boxer, and one German Shepherd dog. TD predominated in males (11 males vs. three females). The body weight of the affected dogs, with the exception of the Miniature Schnauzer, exceeded 20 kg. Two dogs (Boxer and Bull Terrier) had additional congenital cardiac lesions in the form of mitral valve dysplasia. The most affected breeds in the study were the Labrador Retriever and Boxer.
Electrical cardioversion is a therapeutic procedure used to convert various types of arrhythmias back to sinus rhythm. It is used to restore the sinus rhythm in dogs with atrial fibrillation. The effect of the electrical energy used during cardioversion on red blood cells (RBC) is not fully understood. Studies on humans reported lysis of RBC following electrical cardioversion. Similar studies have not been carried out on dogs. The aim of the study was to assess the effect of electrical cardioversion on chosen RBC parameters.
Material and Methods
The study was carried out on 14 large and giant breed dogs weighing from 30 to 84 kg with lone atrial fibrillation (lone AF). Electrical cardioversion was carried out under general anaesthesia by biphasic shock with 70–360 J of energy. Blood was collected at T0 – during atrial fibrillation, prior to cardioversion, and at T1 – 30 min after electrical cardioversion. Complete blood counts as well as total and direct bilirubin concentrations were evaluated. A maximum output of 360 J was used.
In all cases, electrical cardioversion was effective, and no significant changes in the number of RBC and RBC indices were noted. Similarly, there were no statistically significant differences in the levels of total and direct bilirubin.
Electrical cardioversion in dogs led neither to statistically nor clinically significant RBC lysis.
Introduction: Pacemaker implantation is the only effective symptomatic treatment for life-threatening bradyarrhythmias. Major complications observed after implantation of cardiac pacemakers include lead dislocation, loss of pulse generator function, and inadequate stimulation. The aim of this retrospective single-centre study was to analyse the indications for pacemaker implantation and the incidence and types of complications associated with this procedure in dogs treated for symptomatic bradyarrhythmia.
Material and Methods: The retrospective analysis included 31 dogs with symptomatic bradyarrhythmia, implanted with permanent cardiac pacemakers in 1992–2017. The list of analysed variables included patient age, breed, sex, indication for pacemaker implantation, comorbidities, and the incidence of procedure-related complications along with the type thereof.
Results: The most common indication for pacemaker implantation was 3rd degree AVB, followed by SSS, advanced 2nd degree AVB, and PAS. Pacemaker implantation was associated with a 35% overall complication rate and 6.45% periprocedural mortality. There were no significant differences in terms of procedure-related complications with regard to age, sex, breed, indications for pacemaker implantation, or comorbidities.
Conclusions: Cardiac pacing is the only effective treatment of symptomatic bradycardia, but as an invasive procedure, may pose a risk of various complications, including death.
The influence of docosahexaenoic (DHA) acid obtained from a new generation of eggs on ventricular electrical function of 24 pigs with experimentally induced tachycardiomyopathy was described. Two groups were formed, 12 pigs had experimentally evoked tachycardiomyopathy and were getting standard feed (control group TIC). Twelve pigs with tachycardiomyopathy received feed with an addition of a dietary supplement containing phospholipids isolated from new generation of eggs at a dose of 1,000 mg of DHA/animal/24 h (experimental group TIC). Electrophysiological study was carried out from an external programmer immediately after implantation of the pacemaker. All the tests were carried out in general anaesthesia. After 8 weeks of fast ventricular pacing at 170 bpm in pigs receiving phospholipids obtained from eggs, a statistically significant shortening of ventricular refraction time was observed during sinus rhythm and also during the ventricular pacing of 130 bpm, and 150 bpm in the group of pigs fed standard feed. The ventricular refraction time in the sinus rhythm was significantly longer after 12 weeks of fast pacing and in the pacing at 130 bpm and 150 bpm it was significantly longer after 8 weeks of fast pacing. Phospholipids containing high percentage of n-3 polyunsaturated fatty acids (PUFA) obtained from new generation of eggs may contribute to the shortening ventricular refraction period after its oral administration. The n-3 PUFA obtained from a new generation of hen eggs may be an alternative to fish oil source of DHA and other polyunsaturated fatty acids.
The aim of the study was to assess the atrioventricular conduction in the model of porcine pacing induced tachycardiomyopathy. Fifty-one swine were examined: 27 were paced and 24 served as a control group. Every 4 weeks, the animals were anaesthetised for 1 h and an ECG Holter was performed. Thirty minutes after the onset of anaesthesia, P-R and R-R intervals were measured. Each result was assigned to the subgroup according to the animal’s weight and the presence or absence of previous pacing. P-R interval was longer in animals after at least 4 weeks of rapid ventricular stimulation than in adjusted group of the animals according to the body mass. Multivariate analysis has showed that longer P-R interval was related to male gender, higher body mass, slower heart rate, and history of previous pacing. Chronic ventricular pacing led to the slowing of atrioventricular conduction. The presence of differences in the duration of R-R intervals between groups was only found in swine weighing 120-139 kg. The R-R interval was shorter in paced animals, whereas PR interval was longer in that group, indicating that PR prolongation is related to electrical or structural remodelling of the cardiac conductive tissue but not increased sympathetic nervous system activity, which is expected to produce corresponding changes in PR and R-R intervals.