Acute and Long-term Management of Supraventricular Tachycardia (SVT)

Introduction to SVT Management

The American Heart Association recommends intravenous diltiazem as a first-line pharmacological treatment option for acute treatment of hemodynamically stable SVT, with conversion success rates of 64-98% of patients 1, 2
The American College of Cardiology suggests that vagal maneuvers and adenosine should be considered before intravenous diltiazem for acute treatment of SVT 3, 4

For hemodynamically stable patients, the American Heart Association recommends IV diltiazem or verapamil (Class IIa recommendation) as a second-line pharmacological option 1, 2
The American College of Cardiology recommends synchronized cardioversion (Class I recommendation) when pharmacological therapy fails 1, 2
Ensure tachycardia is not ventricular tachycardia or pre-excited atrial fibrillation before administering diltiazem, as these patients may become hemodynamically unstable 1, 2
Diltiazem should be avoided in patients with suspected systolic heart failure 1, 2
A slow infusion of diltiazem up to 20 minutes may reduce the risk of hypotension 1, 2

Oral diltiazem is a Class I recommendation (highest level) for ongoing management of symptomatic SVT in patients without ventricular pre-excitation 5, 2
Other Class I options include oral beta blockers or verapamil, and electrophysiological study with catheter ablation 5, 2, 3
For patients who cannot undergo or prefer not to have catheter ablation, oral diltiazem provides effective long-term control of SVT symptoms 5

Diltiazem is contraindicated in patients with second or third-degree AV block without pacemaker 4
Diltiazem is contraindicated in patients with severe hypotension 2

Synchronized cardioversion is recommended for hemodynamically unstable SVT when pharmacological therapy is ineffective 6

In pregnant patients, IV verapamil may be reasonable for acute treatment when adenosine and beta blockers are ineffective or contraindicated (Class IIb recommendation) 7, 8
Risk of maternal hypotension is higher with verapamil than with adenosine in pregnant patients 7