From the Guidelines
For tachycardia, the first-line treatment should be adenosine 6 mg IV as a rapid push, followed by a 20 mL saline flush, due to its effectiveness in converting stable, narrow-complex regular tachycardias to normal rhythm, as recommended by the 2010 American Heart Association guidelines 1.
Tachycardia Treatment Options
When considering treatment for tachycardia, it's crucial to differentiate between types of tachycardia, such as narrow-complex versus wide-complex, and stable versus unstable. The choice of medication also depends on the presence of underlying heart conditions or other health issues.
- Adenosine is preferred for stable, narrow-complex regular tachycardias due to its rapid onset of action and effectiveness in diagnosing and treating supraventricular tachycardia (SVT) 1.
- For patients with stable, narrow-complex tachycardias that are uncontrolled by adenosine or vagal maneuvers, or in cases of recurrent SVT, calcium channel blockers like diltiazem or verapamil can be used, with dosing as outlined in the guidelines 1.
- Beta-blockers, such as atenolol, esmolol, metoprolol, or propranolol, are also effective for controlling heart rate in stable, narrow-complex tachycardias and in certain cases of wide-complex tachycardias, with specific dosing recommendations provided in the guidelines 1.
Important Considerations
It's essential to consider the potential side effects and contraindications of these medications. For example:
- Adenosine is contraindicated in patients with asthma and may precipitate atrial fibrillation in patients with Wolff-Parkinson-White syndrome, necessitating the availability of a defibrillator 1.
- Calcium channel blockers should be avoided in patients with heart failure and pre-excited atrial fibrillation or flutter 1.
- Beta-blockers are contraindicated in patients with asthma, obstructive airway disease, and decompensated heart failure, among other conditions 1.
Clinical Approach
In clinical practice, the approach to tachycardia involves:
- Initial assessment to determine the type and severity of tachycardia
- Selection of the appropriate medication based on guidelines and patient-specific factors
- Monitoring for effectiveness and potential side effects
- Addressing underlying causes and contributing factors to prevent recurrence Given the complexity and variability of tachycardia presentations, adenosine remains a first-line choice for its efficacy and rapid action in suitable cases, as supported by the highest quality and most recent evidence available 1.
From the FDA Drug Label
Beta-blockers may mask tachycardia occurring with hypoglycemia, but other manifestations such as dizziness and sweating may not be significantly affected
The answer to what to give in tachycardia is not directly stated in the provided drug labels. However, it can be inferred that metoprolol may not be the best choice as it can mask tachycardia.
- Metoprolol is a beta-blocker that can cause bradycardia.
- In cases of hypoglycemia, beta-blockers like metoprolol may mask tachycardia. No conclusion can be drawn on what to give in tachycardia from the provided information 2, 2.
From the Research
Treatment Options for Tachycardia
- Vagal maneuvers may be used to terminate the arrhythmia 3
- Adenosine is effective in the acute setting and can be used as a first-line treatment for supraventricular tachycardia 3, 4, 5, 6, 7
- Calcium channel blockers (diltiazem or verapamil) can be used acutely or as long-term therapy 3
- Beta blockers (metoprolol) can be used acutely or as long-term therapy 3
- Class Ic antiarrhythmics (flecainide or propafenone) can be used long-term 3
- Class Ia antiarrhythmics (quinidine, procainamide, or disopyramide) are used less often due to their modest effectiveness and adverse effects 3
- Class III antiarrhythmics (amiodarone, sotalol, or dofetilide) are effective but have potential adverse effects and should be administered in consultation with a cardiologist 3
- Catheter ablation has a high success rate and can be used as a preferred treatment for symptomatic patients with Wolff-Parkinson-White syndrome 3
Adenosine Dosage
- The standard dosing regimen for adenosine is 6 mg, 12 mg, 12 mg 4
- Higher doses of adenosine (up to 36 mg) may be effective in refractory supraventricular tachycardia 4, 7
- Adenosine has a rapid metabolism and brevity of action, with a half-life of a few seconds 5