title: Cardiac changes after simulated behind armor blunt trauma or impact of nonlethal kinetic projectile ammunition.
abstract: BACKGROUND
  Cardiac-related injuries caused by blunt chest trauma remain a severe problem. The aim of this study was to investigate pathophysiological changes in the heart that might arise after behind armor blunt trauma or impacts of nonlethal projectiles.
  
  
  METHODS
  Sixteen pigs were shot directly at the sternum with "Sponge Round eXact I Mpact" (nonlethal ammunition; diameter 40 mm and weight 28 g) or hard-plastic ammunition (diameter 65 mm and weight 58 g) to simulate behind armor blunt trauma. To evaluate the influence of the shot location, seven additional pigs where exposed to an oblique heart shot. Physiologic parameters, electrocardiography, echocardiogram, the biochemical marker troponin I (TnI), and myocardial injuries were analyzed.
  
  
  RESULTS
  Nonlethal kinetic projectiles (101-108 m/s; 143-163 J) did not cause significant pathophysiological changes. Five of 18 pigs shot with 65-mm plastic projectiles (99-133 m/s; 284-513 J) to the front or side of the thorax died directly after the shot. No major physiologic changes could be observed in surviving animals. Animals shot with an oblique heart shot (99-106 m/s; 284-326 J) demonstrated a small, but significant decrease in saturation. Energy levels over 300 J caused increased TnI and myocardial damages in most of the pigs.
  
  
  CONCLUSIONS
  This study indicates that nonlethal kinetic projectiles "eXact iMpact" does not cause heart-related damage under the examined conditions. On impact, sudden heart arrest may occur independently from the cardiac's electrical cycle. The cardiac enzyme, TnI, can be used as a reliable diagnostic marker to detect heart tissue damages after blunt chest trauma.
authors.affiliation: Department of Forensic Medicine, Ludwig-Maximilians University Munich, Germany. sebastian.kunz@med.uni-muenchen.de
authors.forename: Sebastian N
authors.initials: SN
authors.lastname: Kunz
authors.forename: Ulf P
authors.initials: UP
authors.lastname: Arborelius
authors.forename: Dan
authors.initials: D
authors.lastname: Gryth
authors.forename: Anders
authors.initials: A
authors.lastname: Sonden
authors.forename: Jenny
authors.initials: J
authors.lastname: Gustavsson
authors.forename: Tashi
authors.initials: T
authors.lastname: Wangyal
authors.forename: Leif
authors.initials: L
authors.lastname: Svensson
authors.forename: David
authors.initials: D
authors.lastname: Rocksén
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D004452:Echocardiography; D004562:Electrocardiography; D044709:Forensic Ballistics; D006335:Heart Injuries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007700:Kinetics; D011481:Protective Clothing; D018709:Statistics, Nonparametric; D013552:Swine; D019210:Troponin I / Q000097:blood; D014949:Wounds, Nonpenetrating / Q000000981:diagnostic imaging / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D019210:Troponin I