Treatment of Supraventricular Tachycardia (SVT)
Acute Management
- The American College of Cardiology recommends that the first-line treatment for SVT should begin with vagal maneuvers, followed by adenosine in hemodynamically stable patients, and synchronized cardioversion for unstable patients or when other methods fail 1, 2
- The American Heart Association suggests determining if the patient is hemodynamically stable or unstable, with signs such as hypotension, altered mental status, signs of shock, chest pain, or acute heart failure 3
- Vagal maneuvers have an overall success rate of approximately 27.7% in converting SVT to sinus rhythm, with the modified Valsalva maneuver being the most effective technique 1, 4
- Adenosine is highly effective, with a 90-95% success rate, for terminating AVNRT and orthodromic AVRT, but may cause brief side effects in approximately 30% of patients 4, 5, 6
- Intravenous calcium channel blockers or beta blockers can be used if adenosine fails, with success rates of 80-98% for conversion to sinus rhythm, but should be avoided in patients with suspected VT, pre-excited AF, or systolic heart failure 3, 4, 7, 8
Special Considerations
- For hemodynamically unstable patients, immediate synchronized cardioversion is highly effective for terminating SVT and should be performed promptly when the patient shows signs of hemodynamic compromise 3, 4, 8
- For stable patients with pre-excited AF, ibutilide or IV procainamide are recommended, while avoiding AV nodal blocking agents that may enhance conduction over the accessory pathway 5, 6
Long-term Management
- The American College of Cardiology recommends catheter ablation as the most effective therapy to prevent recurrent SVT, with success rates of 94.3-98.5% 2
- For patients who decline ablation or are not candidates, pharmacological options include oral beta blockers, diltiazem, or verapamil, as well as flecainide or propafenone for patients without structural heart disease 2