> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sonohealth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Heart Attack vs Arrhythmia: What a Home EKG Can and Can't Tell You

> A heart attack and an arrhythmia are different problems. Learn what a single-lead home EKG can detect, what it can't, and the emergency symptoms that mean call 911.

People often expect a home EKG to detect "anything wrong with the heart." In reality, a heart attack and an arrhythmia are different problems, and a single-lead personal EKG is built for one of them. Knowing the difference can be lifesaving.

<Warning>
  A personal EKG cannot reliably detect a heart attack. If you have chest pain or pressure, pain spreading to the arm, jaw, or back, shortness of breath, cold sweat, or nausea, call emergency services (911) immediately. Do not wait to take a reading.
</Warning>

## What is the difference between a heart attack and an arrhythmia?

A **heart attack** is a blood-flow problem — a blocked artery starving heart muscle of oxygen. An **arrhythmia** is an electrical problem — the heart beating too fast, too slow, or irregularly, such as [atrial fibrillation](/ekg/atrial-fibrillation). They can occur together, but they are diagnosed and treated differently.

## What can a single-lead home EKG detect?

A [personal EKG](/ekg/overview) records the heart's electrical rhythm from a single lead. It is designed to **screen for rhythm issues** — including AFib, a fast rate (tachycardia), or a slow rate (bradycardia) — and to capture a tracing you can show your doctor. See [normal heart rate and rhythm](/ekg/normal-heart-rate-rhythm) for what typical looks like.

## Why can't it diagnose a heart attack?

Diagnosing a heart attack typically requires a **12-lead EKG** (which views the heart from many angles) plus blood tests for cardiac enzymes. A single-lead device sees only one view and cannot rule a heart attack in or out. Never use a normal home reading to talk yourself out of seeking emergency care for heart-attack symptoms.

## How should I use my home EKG readings?

Use them to document symptoms — capturing a tracing during palpitations, for instance, gives your doctor valuable information they'd otherwise miss between visits. See [heart palpitations](/ekg/heart-palpitations) and bring your recordings to appointments. The device informs your care; it does not replace your clinician.

## When should I see a doctor (non-emergency)?

Make an appointment if you have frequent palpitations, recurring irregular readings, episodes of feeling your heart race or skip, or fatigue and breathlessness with these symptoms. A cardiologist can interpret your tracings in context.

<Note>
  A personal EKG is a screening and documentation tool, not a diagnostic replacement for clinical testing. When symptoms are severe or sudden, choose emergency care over a home reading every time.
</Note>

**Related:** [EKG Overview](/ekg/overview) · [Atrial Fibrillation](/ekg/atrial-fibrillation) · [Heart Palpitations](/ekg/heart-palpitations) · [When to See a Doctor](/ekg/when-to-see-a-doctor-heart)