The characterization of troponin I levels post synchronised
direct-current cardioversion in patients with atrial arrhythmias.
Abstract
Cardiac-specific markers of myocardial injury, such as troponin I, are
often elevated following procedures that stimulate the myocardium. The
aim of this study was to determine the effect of synchronised DC
cardioversion of an atrial arrhythmia on myocardial injury 6-hours post
procedure, as measured by cardiac troponin I A total of 73 individuals
(59 men, 14 women) undergoing DC cardioversion of an atrial arrhythmia
agreed to participate in this study. Inclusion criteria included
subjects older 18 who were undergoing DC cardioversion for an atrial
arrhythmia. This included elective and non-elective admissions.
Exclusion criteria included an MI or CABG within the past month,
cardioversion for a ventricular arrhythmia, or any recent shocks by an
implantable internal cardioverter defibrillator. Patients underwent
standard procedure for DC cardioversion with blood work (troponin I and
CRP) performed prior to and six hours post cardioversion. Primary
outcome was change in troponin I. Secondary outcomes included changes in
CRP, relationships between troponin I and cumulative energy and LVM, and
a sub-group analysis stratified by the presence of cardiomyopathy. There
was no significant change in troponin I following cardioversion
(F[1,72]=2.651, p=0.108). There was a significant reduction in
troponin I following cardioversion in the non-cardiomyopathy group
(F[1,58]=6.481, p=0.014). There was no significant relationship
between change in troponin I and cumulative energy or LVM (r=0.137,
p=0.306 and r=0.125, p=0.412 respectively). Synchronised DC
cardioversion of an atrial arrhythmia did not cause myocardial injury
6-hours post-cardioversion. Sub-group analysis suggests that
cardioversion of patients with cardiomyopathy may result in
normalization of tropo