What symptom is associated with hypocalcemia?

The symptom associated with hypocalcemia is an increase in neuromuscular excitability, which can manifest as increased muscle contractions and potentially lead to symptoms such as muscle spasms, tetany, and a heightened heart rate. This phenomenon, often termed "fast everything," includes a faster heart rate due to the overexcitability of the nervous system when calcium levels are low. The body responds to low calcium by stimulating the heart more vigorously, thus increasing the heart rate, which aligns with the symptom of being "fast" overall. Therefore, the correct choice reflects the characteristic increase in activity and excitability that occurs with hypocalcemia.