Management of Supraventricular Tachycardia (SVT) in Hemodynamically Stable Patients

Initial Management

The American College of Cardiology recommends vagal maneuvers as the first-line intervention for acute treatment of SVT in hemodynamically stable patients, followed by adenosine if vagal maneuvers fail 1, 2
Vagal maneuvers, such as the Valsalva maneuver and carotid sinus massage, have a success rate of approximately 27.7% when switching between techniques, with modified Valsalva having a higher success rate of about 43% 1, 2
Facial application of ice-cold wet towel can also be used as an alternative vagal maneuver 1, 2

Adenosine is recommended as the second-line treatment for SVT, with a success rate of approximately 95% in terminating AVNRT 1, 2
Adenosine serves both therapeutic and diagnostic purposes by unmasking atrial activity in arrhythmias such as atrial flutter or atrial tachycardia 1, 2
Brief side effects (<1 minute) may occur in approximately 30% of patients treated with adenosine 3
Intravenous diltiazem, verapamil, or beta blockers are reasonable options if adenosine fails, with diltiazem and verapamil being particularly effective in converting AVNRT to sinus rhythm 1, 2

In patients with pre-excited AF, ibutilide or intravenous procainamide should be used instead of calcium channel blockers or beta blockers 3, 5
Calcium channel blockers and beta blockers should be avoided in patients with suspected pre-excitation on ECG, as they may enhance conduction over the accessory pathway if SVT converts to AF, potentially leading to ventricular fibrillation 5
Adenosine can help differentiate between different types of SVT by unmasking underlying atrial activity 1, 2