For every minute that passes between collapse and defibrillation, the chance of survival from a witnessed VF sudden cardiac arrest declines by what percent per minute with CPR?

For every minute that passes between collapse and defibrillation, the chance of survival from a witnessed VF sudden cardiac arrest declines by what percent per minute with CPR?

• A. 1-2% per minute
• B. 5-6% per minute
• C. 3-4% per minute
• D. 7-8% per minute

Answer: (C)

The main idea here is that delaying defibrillation in a witnessed VF arrest reduces the chance of survival, but performing high-quality CPR during that delay slows how quickly that chance falls. With CPR ongoing, the survival probability declines by about 3-4% per minute. This reflects how chest compressions help maintain coronary and cerebral perfusion, keeping tissues viable until a shock can restore rhythm. The other options imply a faster or slower decay than what CPR typically allows: 1-2% per minute is too small to reflect the impact of defibrillation delay, while 5-6% or 7-8% per minute would exceed the protective effect CPR provides. So the best answer is 3-4% per minute.

The main idea here is that delaying defibrillation in a witnessed VF arrest reduces the chance of survival, but performing high-quality CPR during that delay slows how quickly that chance falls. With CPR ongoing, the survival probability declines by about 3-4% per minute. This reflects how chest compressions help maintain coronary and cerebral perfusion, keeping tissues viable until a shock can restore rhythm. The other options imply a faster or slower decay than what CPR typically allows: 1-2% per minute is too small to reflect the impact of defibrillation delay, while 5-6% or 7-8% per minute would exceed the protective effect CPR provides. So the best answer is 3-4% per minute.