Management of Asymptomatic Tachycardia

Initial Assessment and Rhythm Classification

The American College of Cardiology and the American Heart Association recommend evaluating for physiologic causes first, checking oxygen saturation via pulse oximetry, and assessing for signs of increased work of breathing in patients with asymptomatic tachycardia at 120 bpm 1, 3
The American Heart Association suggests attaching a cardiac monitor, measuring blood pressure, and establishing IV access in patients with asymptomatic tachycardia at 120 bpm 3
The American College of Cardiology recommends obtaining a 12-lead ECG to define the rhythm and determine QRS duration, as narrow complex tachycardia is most likely sinus tachycardia or supraventricular tachycardia 2, 3
The American Heart Association states that wide complex tachycardia should be assumed to be ventricular tachycardia until proven otherwise, even in young healthy patients 5, 3
Sinus tachycardia is characterized by gradual acceleration/deceleration and normal P-wave morphology, and requires no specific antiarrhythmic treatment, with therapy targeting the underlying cause 4, 1, 2

The American College of Cardiology recommends identifying and treating reversible causes, such as fever, dehydration, anemia, and hypotension, in patients with asymptomatic tachycardia at 120 bpm 1, 4, 3
The American Heart Association suggests providing supplementary oxygen if hypoxemia is present, and avoiding attempts to "normalize" the heart rate pharmacologically 3, 1, 6
The American College of Cardiology recommends trying vagal maneuvers, such as the Valsalva maneuver, for paroxysmal supraventricular tachycardia, and using adenosine 6 mg rapid IV push, followed by 12 mg if needed, if vagal maneuvers are unsuccessful 5, 2, 3

The American Heart Association warns against treating the number without identifying the rhythm and underlying cause, and against using calcium channel blockers or beta-blockers empirically, as they can cause hemodynamic collapse in patients with ventricular tachycardia with aberrancy 1, 3, 5
The American College of Cardiology recommends against assuming narrow complex means benign, and against cardioverting stable, asymptomatic patients, reserving synchronized cardioversion for hemodynamically unstable patients 1, 3

The American College of Cardiology recommends referring patients with paroxysmal supraventricular tachycardia to a cardiac arrhythmia specialist for consideration of catheter ablation, especially if recurrent or the patient desires freedom from medications 4
The American Heart Association suggests encouraging patients to obtain a 12-lead ECG during any future episodes to establish a definitive diagnosis 4