Sinus tachycardia:
Identify and treat underlying cause.
Supraventricular tachycardia:
If adenosine fails, use verapamil 2.5-5mg IV over 2-3min.
NB: NOT if on a B-blocker. If no response, a further 5mg IV over 3min (if age <60yrs).
Alternatives: atenolol 5mg IV or sotalol 20-120mg IV (over 10min); or amiodarone. If unsuccessful, use DC cardioversion.
Atrial fibrillation/flutter:
Manage along standard lines.
Atrial tachycardia:
Rare; may be due to digoxin toxicity: withdraw digoxin, consider digoxin-specific antibody fragments. Maintain K+ at 4-5mmol/L.
Multifocal atrial tachycardia:
Most commonly occurs in COPD.
Correct hypoxia and hypercapnia. Consider verapamil if rate remains >110bpm.
Junctional tachycardia:
Where anterograde conduction through the AV node occurs, vagal manoeuvres are worth trying. Adenosine will usually cardiovert a junctional rhythm to sinus rhythm.
If it fails or recurs, B-blockers (or verapamil (not with B-blockers, digoxin, or class I agents such as quinidine). If this does not control symptoms, consider radiofrequency ablation.
Wolff-Parkinson-White (WPW) syndrome
Caused by congenital accessory conduction pathway between atria and ventricles. Resting ECG shows short P-R interval and widened QRS complex due to slurred upstroke or delta wave. 2 types: WPW type A (+ve R wave in V1), WPW type B (-ve R wave in V1).
Patients present with SVT which may be due to an AVRT, pre-excited AF, or pre-excited atrial flutter. Risk of degeneration to VF and sudden death. [prescription take] flecainide, propafenone, sotalol, or amiodarone. Refer to cardiologist for electrophysiology and ablation of the accessory pathway.
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