Tachycardia Evaluation and Management

Primary Causes and Diagnostic Approach

The American Heart Association recommends distinguishing between physiological sinus tachycardia and primary cardiac arrhythmias, as management differs completely, in a patient with tachycardia 1
Fever, infection, dehydration, anemia, pain are common causes of sinus tachycardia in young adults and should be identified and corrected first, according to the American College of Cardiology 1, 2
Hyperthyroidism must be excluded with TSH testing, as it commonly presents with persistent tachycardia, as recommended by the Endocrine Society 1, 3
Anxiety and panic disorder are critical pitfalls, as anxiety is frequently the actual diagnosis when SVT is suspected, but conversely, SVT is frequently misdiagnosed as panic disorder, according to the American Psychiatric Association 1, 3

The American College of Cardiology recommends obtaining a 12-lead ECG immediately to document the rhythm, measure QRS duration, identify P-wave morphology and relationship to QRS, and look for pre-excitation (delta waves suggesting WPW) 1, 4, 3
Immediate cardiology referral is required for pre-excitation (WPW syndrome) on ECG, wide-complex tachycardia of unknown origin, syncope during tachycardia or with exercise, and documented sustained SVT, as recommended by the American Heart Association 4, 3

The American College of Cardiology recommends treating the underlying cause, not the heart rate, for physiologic sinus tachycardia, and no specific antiarrhythmic therapy is indicated 1, 4
For acute SVT (hemodynamically stable), vagal maneuvers and/or IV adenosine are recommended (Class I recommendation), according to the American Heart Association 1
For acute SVT (hemodynamically unstable), immediate synchronized cardioversion is recommended, according to the American Heart Association 2, 4