title: Out-of-hospital cardiac arrest: significance of symptoms in patients collapsing before and after arrival of paramedics.
abstract: The authors retrospectively studied victims of sudden cardiac death who experienced cardiac arrest before and after arrival of emergency personnel in order to define possible etiologic factors. There were 265 patients in the arrest-after-arrival (AAA) group and 414 patients in the arrest-before-arrival (ABA) group. All patients in the AAA group had symptoms prior to cardiac arrest. Approximately half the patients in the ABA group had symptoms. The presence or absence of symptoms prior to cardiac arrest appeared strongly associated with the cardiac rhythm at time of collapse and with discharge. Of patients with symptoms, 61% were in ventricular fibrillation or ventricular tachycardia, as compared with 93% of patients without symptoms (P less than 0.001); 32% of patients with symptoms were discharged, as compared with 57% of patients without symptoms (P less than 0.001). These data suggest two potential etiologies for sudden cardiac arrest; thrombosis/ischemia (associated with symptoms) and electrical (associated with no symptoms). Inasmuch as the AAA group represented 14% of witnessed cardiac arrests, patients with symptoms of myocardial ischemia or infarction should be aggressively treated.
mesh_terms: D001145:Arrhythmias, Cardiac / Q000150:complications*; D004632:Emergency Medical Services; D004634:Emergency Medical Technicians; D006323:Heart Arrest / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D006352:Heart Ventricles; D006801:Humans; D010343:Patient Admission; D005082:Physical Exertion; D012189:Retrospective Studies; D013610:Tachycardia / Q000150:complications; D014693:Ventricular Fibrillation / Q000150:complications; D014861:Washington