The threshold current value associated with heart rhythm problems during electrical exposure is which of the following?

The threshold current value associated with heart rhythm problems during electrical exposure is which of the following?

• A. 50 mA
• B. 75 mA
• C. 100 mA
• D. 150 mA

Answer: (B)

The question is about how much current through the body can start causing heart rhythm problems when exposed to electricity. At standard power-line frequencies (about 50–60 Hz), the heart is particularly vulnerable to currents in the tens of milliamperes, and around 75 mA through the chest is the level where dangerous heart rhythms, such as ventricular fibrillation, can begin to occur. Lower currents tend to cause painful shocks or muscle contractions without reliably triggering fatal heart rhythm disturbances, while higher currents increase the risk of severe injury or death. Therefore, 75 mA is used as the threshold for heart rhythm problems in this context, making it the best choice. The other values are either below or above that threshold, but the key point is the level at which the heart’s rhythm becomes jeopardized.

The question is about how much current through the body can start causing heart rhythm problems when exposed to electricity. At standard power-line frequencies (about 50–60 Hz), the heart is particularly vulnerable to currents in the tens of milliamperes, and around 75 mA through the chest is the level where dangerous heart rhythms, such as ventricular fibrillation, can begin to occur. Lower currents tend to cause painful shocks or muscle contractions without reliably triggering fatal heart rhythm disturbances, while higher currents increase the risk of severe injury or death. Therefore, 75 mA is used as the threshold for heart rhythm problems in this context, making it the best choice. The other values are either below or above that threshold, but the key point is the level at which the heart’s rhythm becomes jeopardized.