💓 What is a 24-Hour ECG (Holter Monitor)? A standard ECG shows how your heart is working at one specific moment in time — but heart rhythm changes don’t always happen when you’re sitting in the clinic. A 24-hour ECG, also known as a Holter monitor, records your heart’s electrical activity continuously while you go about your normal daily life. This helps us see what’s happening when you’re exercising, resting, sleeping, or experiencing symptoms. It’s particularly helpful for investigating: ✔️ p