From the Guidelines
The treatment of tachycardia in critical care patients should prioritize synchronized cardioversion for hemodynamically unstable patients with focal atrial tachycardia, as recommended by the 2015 ACC/AHA/HRS guideline 1. For hemodynamically stable patients with focal atrial tachycardia, intravenous beta blockers, diltiazem, or verapamil is useful for acute treatment 1. The choice of treatment depends on the underlying cause of the tachycardia, the patient's hemodynamic stability, and the presence of any underlying cardiac conditions. Some key considerations for treatment include:
- Synchronized cardioversion is recommended for acute treatment in patients with hemodynamically unstable focal atrial tachycardia 1
- Adenosine can be useful in the acute setting to either restore sinus rhythm or diagnose the tachycardia mechanism in patients with suspected focal atrial tachycardia 1
- Intravenous amiodarone may be reasonable in the acute setting to either restore sinus rhythm or slow the ventricular rate in hemodynamically stable patients with focal atrial tachycardia 1
- Ibutilide may be reasonable in the acute setting to restore sinus rhythm in hemodynamically stable patients with focal atrial tachycardia 1 It is essential to continuously monitor the patient's cardiac rhythm, vital signs, and electrolyte levels during treatment, as these can impact the effectiveness of the treatment and the patient's overall outcome.
From the FDA Drug Label
Diltiazem inhibits the influx of calcium (Ca2+) ions during membrane depolarization of cardiac and vascular smooth muscle. The therapeutic benefits of diltiazem in supraventricular tachycardias are related to its ability to slow AV nodal conduction time and prolong AV nodal refractoriness Diltiazem slows the ventricular rate in patients with a rapid ventricular response during atrial fibrillation or atrial flutter Diltiazem converts paroxysmal supraventricular tachycardia (PSVT) to normal sinus rhythm by interrupting the reentry circuit in AV nodal reentrant tachycardias and reciprocating tachycardias, e.g., Wolff-Parkinson-White syndrome (WPW).
Treatment of tachycardia in critical care patients with diltiazem (IV) 2 may be effective, particularly for supraventricular tachycardias.
- Diltiazem can slow the ventricular rate in patients with atrial fibrillation or atrial flutter.
- It can also convert paroxysmal supraventricular tachycardia (PSVT) to normal sinus rhythm. However, for ventricular tachycardia (VT) or ventricular fibrillation (VF), amiodarone (IV) 3 is indicated.
From the Research
Treatment Options for Tachycardia
- The treatment of symptomatic tachycardia is a key challenge in intensive care medicine and emergency care, requiring a structured approach to analyzing and treating arrhythmias 4.
- For unstable hemodynamics, immediate DC-cardioversion is indicated, while conversion of atrial fibrillation (AF) to sinus rhythm (SR) is possible using antiarrhythmic drugs such as amiodarone, which has a conversion rate of up to 80% 5.
- Ibutilide, a class III antiarrhythmic agent, has been reported to have conversion rates of 50-70% for AF and 38-76% for atrial flutter (Aflut) 5.
Management of Arrhythmias in ICU
- Arrhythmias in the cardiovascular intensive care unit (CVICU) can be difficult to manage due to the complex hemodynamic and respiratory states of critically ill patients, requiring a pragmatic approach to patient assessment, arrhythmia diagnosis, and management 6.
- A step-by-step approach, named BEAT, has been proposed for managing cardiovascular insufficiency in ICU, which includes rapid initial ultrasound assessment of heart function, pathophysiological understanding of heart and circulation interaction, functional hemodynamic monitoring, and treatment 7.
Pharmacological Treatment
- Calcium channel blockers, such as verapamil and diltiazem, can be used to treat certain types of tachycardias, but may have negative chronotropic and inotropic effects, and can interact with other drugs such as digoxin and cyclosporine 8.
- Amiodarone is the drug of choice for treating ventricular tachyarrhythmias (VTA) in intensive care patients, and is also effective in patients with defibrillation-resistant out-of-hospital cardiac arrest 5.