Which body organ can be fatally affected by a very small amount of electrical current?

The human heart operates using its own very delicate electrical impulses to maintain a steady pumping rhythm. When an external electrical current passes through the body, it can easily disrupt this natural pacemaker. Even a very small amount of current—as little as 30 to 50 milliamperes—can cause the heart to go into ventricular fibrillation, a chaotic and ineffective twitching that stops blood circulation. This is why the heart is uniquely vulnerable compared to other organs like the brain, lungs, or liver, which do not rely on the same type of synchronized electrical triggering to sustain immediate life.