Incidence of ventricular fibrillation in patients with out-of-hospital cardiac arrest in Japan: survey of survivors after out-of-hospital cardiac arrest in Kanto area (SOS-KANTO).
BACKGROUND
Although there is a close connection between emergency medical services (EMS) system and the outcome of out-of-hospital ventricular fibrillation (VF), few data are available regarding the situation in Japan.


RESULTS
A prospective multicenter study of out-of-hospital cardiac arrest was conducted according to the Utstein guidelines. A total of 4,383 patients who were given cardiopulmonary resuscitation (CPR) by EMS personnel for out-of-hospital cardiac arrest were enrolled. The proportion of VF or pulseless ventricular tachycardia (VT) as the first cardiac rhythm after cardiac arrest was 16.2% with a mean call-to-initial-recorded-electrocardiogram (ECG) interval of 11.1 min. In a subgroup of patients with witnessed collapse, the predicted incidence of VF or pulseless VT was 62.7% at the time of cardiac arrest, and the decline accelerated with every minute that the collapse-to-initial ECG interval was delayed. Multivariate analysis showed that the odds ratio for VF or pulseless VT after collapse-to-initial ECG interval was 0.91 (95% confidence interval (CI), 0.89-0.94, p<0.001), and 1.54 (95%CI, 1.24-1.97, p<0.001) after bystander CPR.


CONCLUSIONS
In Japan, VF occurred in 63% of cases at the time of cardiac arrest and the performance of bystander CPR appeared to prolong VF.
D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation / Q000379:methods; D003625:Data Collection / Q000379:methods; D005260:Female; D006323:Heart Arrest / Q000401:mortality; D006761:Hospitals; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D014693:Ventricular Fibrillation / Q000401:mortality