we have estimated that lidocaine prophylaxis would have to be given to about 12 patients in the highest risk group ( patients under age 50 and within six hours of the onset of symptoms ) , compared to about 400 patients in the lowest risk group ( patients above age 70 and more than 24 hours since the onset of symptoms ) , to prevent one episode of primary ventricular fibrillation in each group .
C0023660
lidocaine
C0042510
ventricular fibrillation