Initial Workup of Symptomatic Tachycardia

Immediate Stabilization and Assessment

The American Heart Association recommends immediate assessment of hemodynamic stability in patients with symptomatic tachycardia, and proceeding directly to synchronized cardioversion without delay for diagnostic workup if the patient shows acute altered mental status, ischemic chest pain, acute heart failure, hypotension, or shock 1, 2
Attach cardiac monitor, obtain vital signs, establish IV access, and assess oxygen saturation in patients with symptomatic tachycardia 3, 2
Provide supplemental oxygen if hypoxemia or respiratory distress is present in patients with symptomatic tachycardia, as hypoxemia commonly drives tachycardia 3, 2

For unstable patients with symptomatic tachycardia, perform immediate synchronized cardioversion, and sedate if conscious and time permits 1, 2
For witnessed, monitored unstable VT, consider precordial thump only if defibrillator not immediately available 1, 2
Do not delay cardioversion to obtain 12-lead ECG in unstable patients with symptomatic tachycardia 1, 2
Presume wide-complex tachycardia is ventricular tachycardia and cardiovert immediately in unstable patients 2

If pre-excitation is present on resting ECG with history of paroxysmal regular palpitations, presume AVRT and refer to electrophysiology without needing to capture the arrhythmia 4
Pre-excitation with irregular paroxysmal palpitations suggests atrial fibrillation, requiring urgent EP evaluation due to sudden death risk 4

Never delay cardioversion in unstable patients while obtaining 12-lead ECG 2
Never use AV nodal blocking agents in pre-excited atrial fibrillation, as this accelerates ventricular response 2
Never give adenosine for irregular or polymorphic wide-complex tachycardia 2
Never normalize heart rate in compensatory tachycardia where cardiac output depends on the rapid rate 2
Never combine multiple AV nodal blocking agents with overlapping half-lives, as this causes profound bradycardia 2

Wide-complex tachycardia of unknown origin requires referral to a specialist 4
Clear history of paroxysmal regular palpitations requires referral to a specialist 4
Drug-resistant or drug-intolerant narrow-complex tachycardia requires referral to a specialist 4
Patients desiring freedom from long-term drug therapy should be referred to a specialist 4
Any suspected ventricular tachycardia, even if self-terminated, requires urgent cardiology consultation and echocardiography 3