Some problems only appear when you are living your ordinary life. Ambulatory monitoring records the heart continuously while you go about your day, which is the only reliable way to catch an intermittent rhythm disturbance or a blood pressure pattern that behaves differently outside the clinic.
Holter and extended rhythm monitoring
A Holter monitor records every heartbeat over 24 to 48 hours through small adhesive electrodes. Where symptoms are less frequent, longer recorders or event monitors extend the window to weeks, which greatly improves the chance of capturing the episode that matters.
The essential task during monitoring is keeping a symptom diary. A recorded abnormality means little unless it can be matched to what you felt at that moment — and equally, a normal recording during a symptomatic episode is genuinely useful information, because it rules the rhythm out.
Ambulatory blood pressure monitoring
A cuff takes readings automatically through the day and night. It gives a far more accurate picture than clinic measurement, identifies white-coat and masked hypertension, and shows whether blood pressure falls overnight as it should — a pattern with independent prognostic value.
Wearing the device
Carry on as normal; an unusually quiet day defeats the purpose. Keep the electrodes dry, avoid strong magnetic fields, and note the time of any palpitation, dizziness, chest discomfort or blackout, along with what you were doing.
Written and medically reviewed by Dr. Gurbir Singh Gill — Interventional Cardiologist & Diabetologist, Oxford Hospital.
Last reviewed: 1 September 2026