using data from 92 ems systems in three geographically distinct and physically dissimilar regions , the authors found a consistent and significant relationship between the probability of patient survival and cardiac disease severity , age , sex , the presence of a life-threatening arrhythmia , health care resources available to the ems system , citizen-initiated cardiopulmonary resuscitation , ems response time , and the presence of a paramedic on the ambulance responding to the call .
C0018799
cardiac disease
C0003811
arrhythmia