Supraventricular Tachycardia (SVT)
Narrow complex regular tachycardia — vagal maneuvers, adenosine, and cardioversion
Overview
- Narrow complex regular tachycardia — vagal maneuvers, adenosine, and cardioversion
Protocol steps
- id: 1; title: Confirm SVT; detail: Narrow complex (<120ms), regular, rapid rhythm. Heart rate usually 150-250 bpm. 12-lead ECG if stable.; time: ; drugs:
- id: 2; title: Unstable — Synchronized Cardioversion; detail: If hemodynamically unstable: synchronized cardioversion 50-100J. Sedate if time permits.; time: ; drugs:
- id: 3; title: Stable — Vagal Maneuvers; detail: Modified Valsalva: supine, bear down for 15 seconds, then passively raise legs 45 degrees for 15 seconds. More effective than traditional Valsalva.; time: ; drugs:
- id: 4; title: Adenosine — First Dose; detail: Rapid IV push through large-bore proximal IV. Follow immediately with 20mL NS flush. Warn patient: brief chest pressure, sense of doom, flushing — lasts seconds.; time: ; drugs: name: Adenosine; dose: 6mg IV rapid push; interval: with 20mL NS flush
- id: 5; title: Adenosine — Second/Third Dose; detail: If no conversion after 1-2 min, give 12mg. May repeat 12mg once. Record rhythm strip during each dose.; time: ; drugs: name: Adenosine; dose: 12mg IV rapid push; interval: may repeat x1
- id: 6; title: No Conversion — Rate Control; detail: If adenosine fails, consider calcium channel blocker or beta-blocker for rate control.; time: ; drugs: name: Diltiazem; dose: 0.25 mg/kg IV over 2min; name: Metoprolol; dose: 5mg IV q5min x3
- id: 7; title: Post-Conversion ECG; detail: 12-lead ECG after conversion. Evaluate for WPW (delta wave, short PR) or other accessory pathway. If WPW identified: avoid AV nodal blockers, consider procainamide.; time: ; drugs:
Source and review
- AHA ACLS Guidelines 2020; Page et al., Circulation 2016. Last reviewed: 2024-11-01