Emergency Medical ServicesThe use of diltiazem for treating rapid atrial fibrillation in the out-of-hospital setting*
Introduction
Atrial fibrillation (AF) is a common dysrhythmia encountered in clinical practice, with a prevalence in the United States ranging from 2.3% in persons older than 40 years to 5.9% in persons older than 65 years.1, 2 Uncontrolled or rapid AF (RAF; atrial fibrillation with an accelerated ventricular response rate [VRR]) can result in impaired diastolic filling, loss of atrial kick, decreased ventricular output, and decreased coronary perfusion. The priority in managing RAF is control of ventricular rate.1, 3, 4 Pharmacologic agents, such as digitalis, β-blockers, calcium channel blockers, and other antiarrhythmic agents, are commonly used for controlling RAF.3, 4, 5, 6, 7, 8
Diltiazem hydrochloride is a commonly used calcium ion channel inhibitor. Diltiazem slows atrioventricular (AV) nodal conduction, prolongs the AV nodal refractory period, and is useful for ventricular rate control of AF.4, 9, 10, 11 Intravenous diltiazem has been demonstrated as an effective treatment for RAF and is widely used in contemporary emergency medicine practice.12, 13, 14 The out-of-hospital use of diltiazem has been relatively limited because of difficulties with field storage of the drug; the original solution requires refrigerated storage at 2°C to 8°C (35.6°F to 46.4°F).15 However, the introduction of lyophilized diltiazem has permitted the storage and use of diltiazem under field conditions. This system uses a dual-chamber syringe containing lyophilized diltiazem powder and a benzyl alcohol–based diluent and may be stored at 15°C to 30°C (59°F to 86°F).9 There have been few reports of diltiazem use in the out-of-hospital setting for RAF.15, 16 The purpose of this study was to evaluate the utility and safety of intravenous diltiazem for treating RAF within the clinical constraints of out-of-hospital care.
Section snippets
Materials and methods
This study is a retrospective review with historic control subjects. Data were drawn from out-of-hospital charts for 3 county-based paramedic systems. Each system is autonomous but operates by using statewide standing orders for patient care. Each system uses 2-person paramedic units, and a total of 15 units (plus supervisor units) serves the state at any given time. The 3 systems serve a population of approximately 745,000 in urban, suburban, and rural settings. All paramedics are trained in
Results
For the intervention period, there were 17,048 patient contacts, with administration of diltiazem identified in 50 cases. Six patients were omitted because the underlying rhythm was PSVT, and 1 was omitted because of inadequate documentation, resulting in a total of 43 subjects in the diltiazem group. No patients receiving diltiazem required exclusion because of intubation, cardioversion, or resuscitation from cardiac arrest. For the control period, there were 25,924 patient contacts, resulting
Discussion
The morbidity associated with AF is attributed to excessive ventricular rate, syncope after cessation of AF, systemic embolization, loss of atrial contribution to cardiac output, and anxiety from palpitations.23 The clinical approach to AF in the ED depends on the condition of the patient. In the setting of a clinically compromised patient, urgent cardioversion is usually indicated.3, 6, 23, 24 Patients who have AF with a rapid VRR but who are clinically stable may benefit from a short trial of
Acknowledgements
We thank Musa Nsereko, BDS, MPH, Statistician, Performance Improvement Department, Christiana Care Health System, for his assistance with the statistical analysis for this study.
References (39)
- et al.
Management of atrial fibrillation in adults: prevention of thromboembolism and symptomatic treatment
Mayo Clin Proc
(1996) - et al.
Atrial fibrillation 1992. Management strategies in flux
Chest
(1992) - et al.
Emergency management of atrial fibrillation and flutter: intravenous diltiazem versus intravenous digoxin
Ann Emerg Med
(1997) - et al.
Efficacy and safety of intravenous diltiazem for treatment of atrial fibrillation and atrial flutter. The Diltiazem-Atrial Fibrillation/Flutter Study Group
Am J Cardiol
(1989) - et al.
Safety and efficacy of intravenous diltiazem in atrial fibrillation or atrial flutter
Am J Cardiol
(1995) - et al.
Out-of-hospital use of intravenous diltiazem (cardizem Lyo-Ject) in the treatment of rapid atrial fibrillation [letter]
Am J Emerg Med
(1997) - et al.
Dilemmas in the acute pharmacologic treatment of uncontrolled atrial fibrillation
Am J Emerg Med
(1997) - et al.
Intravenous diltiazem for the treatment of patients with atrial fibrillation or flutter and moderate to severe congestive heart failure
Am J Cardiol
(1994) - et al.
A randomized, double-blind comparison of intravenous diltiazem and digoxin for atrial fibrillation after coronary artery bypass surgery
Am Heart J
(1998) - et al.
A placebo-controlled trial of continuous intravenous diltiazem infusion for 24-hour heart rate control during atrial fibrillation and atrial flutter: a multicenter study
J Am Coll Cardiol
(1991)
Dangers of defibrillation: injuries to emergency personnel during patient resuscitation
Am J Emerg Med
Effects of intravenous diltiazem on rapid atrial fibrillation accompanied by congestive heart failure
Am J Cardiol
Ventricular fibrillation following verapamil in the Wolff-Parkinson-White syndrome
Am Heart J
Effects of verapamil on the electrophysiologic properties of the accessory pathway in patients with the Wolff-Parkinson-White syndrome
Am J Cardiol
Fatal ventricular fibrillation following verapamil in Wolff-Parkinson-White syndrome with atrial fibrillation
Ann Emerg Med
Role of calcium antagonists for heart rate control in atrial fibrillation
Am J Cardiol
Prevalence, age distribution, and gender of patients with atrial fibrillation. Analysis and implications
Arch Intern Med
Disturbances of cardiac rhythm and conduction
Management of rapid ventricular rate in acute atrial fibrillation
Int J Clin Pharmacol Ther
Cited by (0)
- *
Address for reprints: Henry E. Wang, MD, Department of Emergency Medicine, University of Pittsburgh School of Medicine, 230 McKee Place, Suite 400, Pittsburgh, PA 15213; 412-303-7793, 412-647-4925; E-mail [email protected].