Analysis of haematological and biochemical blood parameters after electrical cardioversion of atrial fibrillation in dogs

Abstract

Introduction: 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. Results: 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 st atistically significant differences in the levels of total and direct bilirubin. Conclusion: Electrical cardioversion in dogs led neither to statistically nor clinically significant RBC lysis.

Right atrial thrombus formation in a dog after successful electrical cardioversion for atrial fibrillation

“…Why atrial thrombus formation in dogs with atrial fibrillation is much less frequent compared to people is unknown 15 . A study of dogs with atrial fibrillation found no differences in various blood test results before and after electrical cardioversion, but coagulation parameters were not determined 16 . A possible explanation for the absence of thrombus formation after electrical cardioversion in dogs is that electrical cardioversion is a much less frequently performed procedure in dogs compared to humans and, even when it is performed, postcardioversion echocardiography is not routinely performed.…”

“… 15 A study of dogs with atrial fibrillation found no differences in various blood test results before and after electrical cardioversion, but coagulation parameters were not determined. 16 A possible explanation for the absence of thrombus formation after electrical cardioversion in dogs is that electrical cardioversion is a much less frequently performed procedure in dogs compared to humans and, even when it is performed, postcardioversion echocardiography is not routinely performed. Furthermore, most dogs develop atrial fibrillation secondary to structural heart disease, with severe mitral valve insufficiency being the predominant structural lesion, which may limit blood stasis, lessening thrombotic risk.…”

Acute Renal Failure and Hemolytic Anemia After Electrical Cardioversion In A Patient With Paroxysmal Atrial Fibrillation.

“…Indeed this information refers to the action of high voltage electrical energy, much higher than EC, to restore Afb. Moreover, Noszczyk-Nowak et al [12] suggested that low voltage EC in dogs did not affect red blood cells either clinically or statistically after the successful restoration of Afb. A limitation of their study was that blood sampling was done immediately after the shock, so the EC's effects might differ after a more extended period.…”