From fingertips to the ECG
Physicians in ancient China and Greece felt irregular pulses at the wrist, but seeing the cause became possible only in 1903, when Dutch physiologist Willem Einthoven recorded the electrocardiogram with a string galvanometer—work that earned him the 1924 Nobel Prize. British cardiologist Thomas Lewis then used the ECG to classify rhythms like atrial fibrillation. The first implanted pacemaker (1958), Michel Mirowski's implantable defibrillator (1980), and radiofrequency catheter ablation in the 1990s transformed care, and today smartwatches screen for arrhythmias on your wrist.
Types and symptoms
The most common are premature beats (PVCs or PACs)—a skipped or "flip-flop" feeling that's usually harmless. Among fast rhythms, AFib raises stroke risk about fivefold, while SVT starts and stops abruptly. Ventricular tachycardia and fibrillation, often after a heart attack, can cause sudden cardiac death. Slow rhythms bring dizziness, fainting, and fatigue. Typical triggers include caffeine, alcohol, poor sleep, stress, an overactive thyroid, and electrolyte imbalances.
Testing and treatment
An ECG captured during symptoms is gold; for occasional episodes doctors use a 24–48-hour Holter, a patch monitor, or an implantable loop recorder. Harmless extra beats often just need fewer triggers. Fast rhythms may be controlled with beta-blockers or antiarrhythmics, and frequent recurrences can often be cured by catheter ablation of the faulty circuit. Severe bradycardia calls for a pacemaker, high risk of dangerous ventricular rhythms for an ICD, and AFib frequently for blood thinners to prevent stroke. Seek care right away if palpitations come with fainting or chest pain.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- Can I trust my smartwatch's AFib alert?
- It's fairly accurate for screening, but a medical-grade ECG confirms the diagnosis.
- I'm a runner with a resting rate of 50. Is that a problem?
- Probably not—athletes often have a healthy, slow heart. Dizziness or fainting would change that.
Sources reviewed: 2026-10-26
References
- Zeppenfeld, K., et al. (2022). 2022 ESC Guidelines for ventricular arrhythmias and the prevention of sudden cardiac death. European Heart Journal, 43(40), 3997–4126.
- Joglar, J. A., et al. (2024). 2023 ACC/AHA/ACCP/HRS Guideline for the diagnosis and management of atrial fibrillation. Circulation, 149(1), e1–e156.
- Einthoven, W. (1903). Die galvanometrische Registrirung des menschlichen Elektrokardiogramms. Pflügers Archiv, 99, 472–480.