`Name`: an `enzyme` used for patients suffering from `heart` ``attack``.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of an enzyme that is used for patients suffering from a heart attack.

2. **Identifying the Relevant Enzyme**: In the context of heart attacks, one of the key treatments involves the use of enzymes that can help dissolve blood clots that block the flow of blood to the heart.

3. **Naming the Enzyme**: The specific enzyme used in this context is **streptokinase**.

4. **Function of Streptokinase**: Streptokinase acts as a "clot buster," meaning it helps to break down blood clots that can cause heart attacks by restoring blood flow.

5. **Source of Streptokinase**: This enzyme is derived from a type of bacteria known as **Streptococcus**.

6. **Conclusion**: Therefore, the answer to the question is that the enzyme used for patients suffering from a heart attack is **streptokinase**.

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