Understanding your tests

Your Zio or Rhythm Monitor

A wearable ECG monitor records your rhythm during everyday life so symptoms and heartbeats can be compared.

Updated

Why wear a monitor?

Palpitations, dizziness or fainting can come and go. A short office ECG may miss an episode. A patch, Holter or event monitor records for the period your clinician selects. Different devices record or transmit data differently.

While wearing it

Follow the instructions for your exact device, including wear time, showering, exercise and return shipping. Log the time of symptoms and what you were doing. If instructed, press the event button as well. Contact the device service or ordering office for a loose patch, skin problems or questions about use.

The manufacturer's MyZio information explains symptom logging for Zio users. Recording a symptom is not the same as requesting urgent help.

Understanding common findings

  • Sinus rhythm: a rhythm starting from the heart's usual pacemaker.
  • PACs and PVCs: early beats from the upper or lower chambers. Their frequency, pattern, your symptoms and heart structure affect their significance.
  • Burden: how much of the recording contains a particular rhythm or type of beat.
  • Runs or episodes: groups of beats described by their rhythm, speed and duration. A short report label does not determine treatment by itself.

Getting the result

Return the device as instructed and ask when and how the report will be reviewed. Your clinician considers the rhythm strips and symptom timing, not just an automated summary. Some monitors are reviewed after they are returned; do not assume yours is watched continuously.

For severe chest pain, fainting, stroke symptoms or severe breathlessness, call 911 instead of waiting for the monitor or its report.

Questions for your next visit

  • What question is this monitor meant to answer?
  • How do I log symptoms and return my device?
  • Which findings matter, and when will we review the results?

References and further reading

  1. AHA: Holter Monitor (2025)
  2. AHA: Cardiac Event Recorder
  3. AHA: Premature Contractions - PACs and PVCs (2024)
  4. iRhythm: MyZio patient app and symptom logging

Use these sources with your own clinician's advice. Recommendations depend on your health history and can change as evidence develops.