title: Evaluation of the skin-to-heart distance in the standing adult by two-dimensional echocardiography.
abstract: BACKGROUND
  An electromuscular incapacitating device (EMD) delivers pulses of high-voltage electricity, causing strong muscle contraction. Data from a pig model suggest that an EMD dart tip placed within 17 mm of the epicardial surface can cause ventricular fibrillation. The current study estimates minimum skin-to-heart distance in the adult, to determine whether individuals might be at risk for ventricular fibrillation from an EMD.
  
  
  METHODS
  We performed 2-dimensional echocardiograms in 150 standing adults in the parasternal, apical, and subcostal views. From each view, the shortest linear skin-to-heart distance was measured.
  
  
  RESULTS
  Average skin-to-heart distances were: parasternal 32.1 +/- 7.9 mm; apical 31.3 +/- 11.3 mm; and subcostal 70.8 +/- 22.3 mm. There were 9 (6%) individuals with a skin-to-heart distance less than or equal to 17 mm. The skin-to-heart distance was significantly correlated with body mass index: parasternal r = 0.57, apical r = 0.55 (P < .0001).
  
  
  CONCLUSIONS
  An EMD dart penetrating the skin directly over the heart might put individuals at risk for ventricular fibrillation.
authors.affiliation: University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792, USA. psr@medicine.wisc.edu
authors.forename: Peter S
authors.initials: PS
authors.lastname: Rahko
mesh_terms: D000328:Adult; D015992:Body Mass Index; D004452:Echocardiography; D004558:Electric Stimulation / Q000009:adverse effects* / Q000295:instrumentation; D005260:Female; D006321:Heart / Q000033:anatomy & histology; D006801:Humans; D035846:Law Enforcement; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D012016:Reference Values; D012307:Risk Factors; D012867:Skin / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014693:Ventricular Fibrillation / Q000000981:diagnostic imaging / Q000209:etiology*