From the Guidelines
A tachycardia workup should begin with a thorough history and physical examination, followed by an ECG to determine the type of tachycardia (sinus, supraventricular, or ventricular) as recommended by the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1. The initial step in managing tachycardia is to assess the patient's stability, with unstable patients requiring immediate cardioversion if they have a wide-complex tachycardia presumed to be ventricular tachycardia (VT) 1. For stable patients, obtaining a 12-lead ECG is crucial to evaluate the rhythm and consider expert consultation if needed 1. Key considerations in the management of tachycardia include:
- Determining the type of tachycardia (supraventricular or ventricular) and its regularity or irregularity to guide treatment decisions 1
- Using medications such as adenosine, beta-blockers (e.g., metoprolol), calcium channel blockers (e.g., diltiazem), or antiarrhythmics (e.g., flecainide) based on the type of tachycardia and patient stability 1
- Considering catheter ablation for recurrent episodes of tachycardia or implantable cardioverter-defibrillators in high-risk cases of ventricular tachycardia 1 The workup and management of tachycardia are critical because untreated tachycardia can lead to serious complications such as heart failure, stroke, or sudden cardiac death, especially when it reflects underlying structural heart disease or electrical abnormalities 1.
From the Research
Tachycardia Workup
- The diagnosis of supraventricular tachycardia (SVT) is crucial and can be achieved through a comprehensive history and physical examination, electrocardiography, and laboratory workup 2, 3, 4.
- A 12-lead electrocardiogram should be a routine aid in making the diagnosis, and a continuous rhythm strip must be obtained during administration of adenosine and at the termination of tachycardia 5.
- Extended cardiac monitoring with a Holter monitor or event recorder may be needed to confirm the diagnosis 2, 3, 4.
Diagnostic Evaluation
- The history is important to elicit episodic symptoms because physical examination and electrocardiography findings may be normal 2.
- Presenting symptoms may include altered consciousness, chest pressure or discomfort, dyspnea, fatigue, lightheadedness, or palpitations 3, 4.
- Diagnostic evaluation may be performed in the outpatient setting and includes a comprehensive history and physical examination, electrocardiography, and laboratory workup 3.
Management
- Vagal maneuvers may terminate the arrhythmia; if this fails, adenosine is effective in the acute setting 2, 5, 4.
- Calcium channel blockers (diltiazem or verapamil) or beta blockers (metoprolol) can be used acutely or as long-term therapy 2, 4.
- Class Ic antiarrhythmics (flecainide or propafenone) can be used long-term, while Class Ia antiarrhythmics (quinidine, procainamide, or disopyramide) are used less often due to their modest effectiveness and adverse effects 2.
- 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, 3, 4.
Comparison of Treatments
- Adenosine and calcium channel antagonists (CCAs) are both effective in terminating SVT, but have significant side effect profiles 6.
- Moderate-quality evidence shows no differences in the number of people reverting to sinus rhythm who were treated with adenosine or CCA 6.
- Low-quality evidence suggests no appreciable differences in major adverse event rates between CCAs and adenosine 6.