From the Guidelines
The initial workup for a patient with tachycardia should begin with a thorough assessment of vital signs, focused history, and physical examination to determine hemodynamic stability and identify the underlying cause, as recommended by the 2015 ESC guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death 1. Obtain a 12-lead ECG immediately to classify the tachycardia as supraventricular (narrow complex) or ventricular (wide complex), which guides management. Some key points to consider in the management of tachycardia include:
- Laboratory tests including electrolytes, complete blood count, thyroid function, and cardiac enzymes should be ordered.
- For unstable patients with signs of shock, altered mental status, chest pain, or hypotension, immediate synchronized cardioversion at 100-200 joules is indicated, as suggested by the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1.
- For stable patients with supraventricular tachycardia, vagal maneuvers should be attempted first, followed by adenosine 6 mg IV push if unsuccessful, with a second dose of 12 mg if needed.
- Beta-blockers (metoprolol 5 mg IV) or calcium channel blockers (diltiazem 0.25 mg/kg IV) can be used for atrial fibrillation or flutter with rapid ventricular response.
- For stable ventricular tachycardia, amiodarone 150 mg IV over 10 minutes is the first-line medication, as recommended by the 2015 ESC guidelines 1 and the 1996 ACC/AHA guidelines for the management of patients with acute myocardial infarction 1. Underlying causes such as sepsis, dehydration, pain, anxiety, or medication effects should be addressed simultaneously. Continuous cardiac monitoring is essential throughout management, and consultation with cardiology is recommended for complex cases or when the cause remains unclear. This approach balances immediate stabilization with diagnostic evaluation to ensure appropriate treatment of both the tachycardia and its underlying cause.
From the Research
Initial Workup for Tachycardia
- The initial workup for a patient presenting with tachycardia includes a comprehensive history and physical examination, electrocardiography, and laboratory workup 2.
- Extended cardiac monitoring with a Holter monitor or event recorder may be needed to confirm the diagnosis 2.
- The primary goal of the initial ECG evaluation is to determine whether the tachyarrhythmia has a ventricular or supraventricular origin 3.
Management of Supraventricular Tachycardia (SVT)
- Acute management of paroxysmal SVT is similar across the various types and is best completed in the emergency department or hospital setting 2.
- In patients who are hemodynamically unstable, synchronized cardioversion is first-line management 2.
- In those who are hemodynamically stable, vagal maneuvers are first-line management, followed by stepwise medication management if ineffective 2.
- Beta blockers and/or calcium channel blockers may be used acutely or for long-term suppressive therapy 2.
Management of Ventricular Tachycardia (VT)
- Emergency treatment of VT follows the Advanced Cardiac Life Support (ACLS) algorithms for pulseless VT and stable and unstable VT with a pulse 4.
- Catheter ablation and antiarrhythmic drugs (AADs) reduce ICD shocks in patients with ischemic cardiomyopathy and an implantable cardioverter-defibrillator (ICD) 5.
- In patients with ischemic cardiomyopathy and symptomatic VT, catheter ablation reduced the composite endpoint of cardiovascular death, appropriate ICD shock, hospitalization due to heart failure, or severe treatment-related complications compared to AAD 5.
Role of Catheter Ablation
- Catheter ablation has a high success rate and is recommended as the first-line method for long-term management of recurrent, symptomatic paroxysmal SVT, including Wolff-Parkinson-White syndrome 2.
- Radiofrequency catheter ablation targeting all inducible monomorphic VTs that allowed mapping was effective in controlling VT in 67% of patients despite failure of antiarrhythmic drug therapy and multiple inducible VTs 6.