Atrial fibrillation, atrial flutter and heart rate

In atrial fibrillation, electrical activity in the upper chambers is disorganised, so the pulse is typically irregular. In atrial flutter, those chambers activate in a more organised circuit; the pulse may be fast and can feel regular or irregular depending on how many impulses reach the lower chambers.

A wrist reading shows the pulse reaching the body, not the full electrical pattern inside the heart. The rate can change with activity, illness, dehydration, medicines or the rhythm itself. Palpitations, tiredness, breathlessness and dizziness can accompany either rhythm, while some people notice no symptoms.

Sit down, rest and repeat the pulse measurement after you have settled. Record the reading, whether it felt regular, the time, what you were doing and any symptoms. A wearable alert can be useful context, but it does not establish which rhythm is present.

Arrange clinical assessment for a new, repeatedly fast or persistently irregular pulse. An ECG can distinguish atrial fibrillation from flutter and other rhythms. Management may address the heart rate, attempt rhythm control and assess whether anticoagulation is appropriate to reduce clot-related stroke risk. Do not change a heart medicine or anticoagulant on the basis of a home reading alone.

Seek emergency help for chest pain, severe breathlessness, collapse or near-collapse, or a racing heartbeat with marked weakness. Sudden facial droop, one-sided weakness, trouble speaking, loss of vision or a severe new balance problem can signal a stroke and needs immediate emergency care, even if it clears.

For milder but new palpitations, worsening exercise tolerance or recurrent light-headedness, contact a clinician promptly. The symptoms and their effect on circulation determine urgency; the pulse number by itself does not tell the whole story.

Ask which rhythm the ECG shows, what heart-rate target suits your situation, whether monitoring is needed, and what should trigger an urgent review. Also clarify each medicine's purpose, what to do after a missed dose and whether your stroke-risk assessment supports anticoagulation.