Effect of transvenous electrical cardioversion on plasma cardiac troponin I concentrations in horses with atrial fibrillation.

The research paper investigates the impact of transvenous electrical cardioversion (TVEC), a procedure for correcting heart arrhythmias, on plasma cardiac troponin I concentrations in horses and checks whether this process inflicts damage to heart cells. It finds a statistically significant increase in cTnI, a marker for heart cell damage, post-procedure but suggests this increase is probably not clinically significant.

Research Objective

• The main purpose of the research was to assess the effects of TVEC—a procedure used to restore heart’s rhythm—on the levels of plasma cTnI in horses. cTnI is a biomarker which, at high concentrations, signals cardiac muscle injury or damage.

Methods

• The study was an observational one, conducted with data collected from a total of 14 horses brought to the Cornell University Hospital for Animals for cardioversion of atrial fibrillation, a type of heart rhythm disorder.
• The study period ran from May 2006 to October 2008.
• In total, there were 16 procedures conducted on the 14 horses.
• The plasma cTnI concentrations in the horses were monitored both before and after they underwent TVEC.

Results

• The median cTnI concentration recorded in these horses rose from 0.045 ng/mL before the procedure to 0.11 ng/mL after the procedure. This increase was found to be statistically significant (P=.036).
• The study did not find a relationship between the increase in cTnI levels and factors like the number of shocks delivered, the maximum energy administered, the total energy administered, how long the horse had had atrial fibrillation before the procedure, or how the catheter was placed in the pulmonary artery during the procedure.

Conclusions

• Although the study found a significant increase in cTnI levels following TVEC, it posited that this increase is unlikely to be clinically important, meaning it probably does not indicate a harmful degree of cardiomyocyte (cardiac muscle cell) damage.
• The paper suggested that the rise in cTnI might have a correlation with a continued dysfunction of the atria following TVEC. Consequently, it recommended a possibly longer recovery period for horses after the procedure.