Without a plateau extending the refractory period in cardiac muscle, sarcomeres might be stimulated so quickly that they would contract and not relax and instead would experience a sustained contraction, also called .

The answer is - Tetany

Explanation:

Tetany is a sustained contraction which can either be fused (one smooth sustained contraction plateau) or unfused (incomplete due to wavering contraction). Tetany occurs when the muscle contracts uncontrollably and can also be as a result of electrolyte imbalance such as low calcium, magnesium deficiency, low potassium. When the sarcomeres are stimulated so quickly causing a sustained contraction it is called tetany.

TETANY

Explanation: Generally,TETANY (tetanic seizure) is a medical sign or condition that is characterised by intermittent involuntary muscle spasm/contraction.

Tetany is caused by malfunction of the parathyroid gland(leading to low level of calcium in the blood) and a subsequent deficiency of calcium(hypocalcemia).

Symptoms of tetany are spasms of the hands and feet, cramps, spasm of the voice box (larynx), and overactive neurological reflexes.

TETANY can also be caused magnesium and potassium deficiency.

Treatment of tetany is with intravenous or oral administration of calcium to replace the deficiency in the blood and the administration of vitamin D supplements.

answer:

it could come from a variety of sources.

explanation:

..although it was most likely developed through zoonotic transmission, where an infectious disease which usually afflicts when animals jump to humans.