1.41
Code 1.41 — persistent supraventricular rhythm / tachycardia (Novacode rhythm class 1, equivalent to Minnesota Code 8-4-1). Supraventricular tachycardia (SVT) is an abnormally fast heart rhythm arising from improper electrical activity in the upper part of the heart — the atria or the atrioventricular (AV) node. Code 1.41 describes a supraventricular rhythm with narrow QRS complexes that is present throughout the recording.
Types of supraventricular tachycardia
| Type | Mechanism | Typical ECG |
|---|---|---|
| AV nodal re-entrant tachycardia (AVNRT) | Re-entry circuit within or near the AV node — the most common SVT | Regular narrow QRS, P waves hidden in or just after QRS |
| AV re-entrant tachycardia (AVRT) | Circuit using an accessory pathway (e.g. WPW) | Regular narrow QRS, retrograde P after QRS |
| Focal atrial tachycardia | Rapid firing from one atrial focus | Abnormal P waves before each QRS |
| Atrial flutter (regular conduction) | Macro-re-entry in the right atrium | "Saw-tooth" flutter waves, often 2:1 conduction ≈ 150 bpm |
Symptoms and risks
- Sudden onset and termination of palpitations, often felt in the neck
- Dizziness, shortness of breath, chest discomfort, anxiety, need to urinate after the episode
- Fainting is uncommon but possible at very high rates or with underlying heart disease
- SVT is usually not life-threatening in a structurally normal heart, but persistent tachycardia lasting weeks can weaken the heart muscle (tachycardia-induced cardiomyopathy)
Management
Acute episodes are often stopped by vagal manoeuvres (for example the modified Valsalva manoeuvre); if unsuccessful, intravenous adenosine is used in hospital. Recurrent SVT can be prevented with medicines or, very effectively, cured by catheter ablation. Persistent SVT recorded on the ECG requires assessment by a cardiologist.
if a fast heartbeat is accompanied by chest pain, fainting, severe breathlessness, or does not stop within 15–20 minutes.
References
- Page RL, Joglar JA, Caldwell MA, et al. 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia. Circulation. 2016;133(14):e506–e574. doi:10.1161/CIR.0000000000000311
- Prineas RJ, Crow RS, Zhang ZM. The Minnesota Code Manual of Electrocardiographic Findings. 2nd ed. London: Springer; 2010. doi:10.1007/978-1-84882-778-3
This article is for general information and does not replace a consultation with a doctor. ECG findings must be interpreted by a physician together with symptoms and other tests.
Published on 14 May 2019