title: Early repolarization in patients with spinal cord injury: prevalence and clinical significance.
abstract: OBJECTIVE
  The objective was to examine the prevalence of early repolarization in a spinal cord injury (SCI) clinic and the relationship of level of injury to this electrocardiogram (ECG) finding.
  
  
  BACKGROUND
  ST elevation on the resting ECG can be either a normal variant or a sign of acute ischemia, evolving myocardial infarction, or pericarditis. It is frequently seen as a normal variant (early repolarization) in healthy individuals, but has also been reported in individuals with SCI. While the etiology of benign ST elevation (early repolarization) has not been clearly defined, current opinion is that this finding is seen in individuals with high vagal tone.
  
  
  METHODS
  Retrospective analysis was made of 31 5 individuals with SCI at T5 or above (140 with complete injuries), and 1 98 with SCI at T6 or below, and who had ECGs in the computerized database at the Palo Alto VA Medical Center. A comparison cohort of 32,841 able-bodied male controls also was identified in the same ECG database. Patient demographics and computerized ST measurements were analyzed.
  
  
  RESULTS
  The prevalence of ST elevation was significantly higher in both the total high-level injury group (19%) and the complete high-injury group (24.5%) than in either the low-injury (6.5%) or control groups (13%), with P < 0.001 for comparisons between both high- and low-injury groups and high injury vs control. The magnitude of ST elevation was also higher in the high-injury groups vs the low-injury and control groups.
  
  
  CONCLUSIONS
  There is a higher prevalence of early repolarization in individuals with SCI at levels of injury that can disrupt central sympathetic command of the heart. It appears that either enhanced vagal tone or loss of sympathetic tone is responsible for ST elevation.
authors.affiliation: Department of Cardiology, Stanford University, California, USA.
authors.forename: Rachel R
authors.initials: RR
authors.lastname: Marcus
authors.forename: Damayanthi
authors.initials: D
authors.lastname: Kalisetti
authors.forename: Vinod
authors.initials: V
authors.lastname: Raxwal
authors.forename: B Jenny
authors.initials: BJ
authors.lastname: Kiratli
authors.forename: Jonathan
authors.initials: J
authors.lastname: Myers
authors.forename: Inder
authors.initials: I
authors.lastname: Perkash
authors.forename: Victor F
authors.initials: VF
authors.lastname: Froelicher
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D013904:Thoracic Vertebrae / Q000503:physiopathology; D013997:Time Factors; D015599:Trauma Severity Indices