The medical assistant can assist Shirley in the following ways:
1. Explain the importance of the ECG test and how it can help detect any heart problems that she may have.
2. Reassure Shirley that the test is quick and painless, and that she will not feel any discomfort during the procedure.
3. Provide Shirley with information on what to expect during the test, including how long it will take and what she needs to do to prepare for it.
4. Answer any questions that Shirley may have about the test, and provide her with any additional information or resources that she may need.
5. Offer to stay with Shirley during the test to provide her with emotional support and reassurance.
6. If Shirley is still anxious about the test, the medical assistant can speak to the doctor to see if there are any alternative tests or procedures that can be done to assess Shirley's heart health.