Final answer:
Tall, peaked T waves on an ECG can indicate hyperkalemia, which is an elevated blood potassium level. Hyperkalemia affects the function of the heart and can be fatal. Hypokalemia, hypercalcemia, and hypocalcemia do not typically cause tall, peaked T waves.
Step-by-step explanation:
Tall, peaked T waves on an ECG can indicate different conditions. One of these conditions is hyperkalemia, which is an elevated blood potassium level. Hyperkalemia can impair the function of the heart by causing partial depolarization of cardiac cells, leading to an inability to repolarize and relax after a contraction. This can result in the heart seizing and stopping pumping blood, which can be fatal within minutes.
Hypokalemia, on the other hand, which is low blood potassium level, does not cause tall, peaked T waves. In hypercalcemia (high blood calcium level) and hypocalcemia (low blood calcium level), the T wave may be widened, but it is not necessarily tall and peaked.