eMedicine Specialties > Cardiology > Arrhythmias
Junctional Rhythm: Treatment & Medication
Updated: Aug 24, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
Treatment
Medical Care
The decision to treat a junctional rhythm depends on the underlying cause and the stability of the patient.
- No pharmacologic therapy is needed for asymptomatic, otherwise healthy individuals with junctional rhythms that result from increased vagal tone.
- In patients with complete AV block, high-grade AV block, or symptomatic sick sinus syndrome (ie, sinus node dysfunction), a permanent pacemaker may be needed. The junctional rhythm serves as an escape mechanism to maintain the heart rate during periods of bradycardia or asystole and should not be suppressed.
- Emergency department care can include evaluation of the 12-lead ECG findings, airway protection and oxygenation, and blood pressure support, depending on the cause of the rhythm.
- If the junctional rhythm is due to digitalis toxicity, then atropine, digoxin immune Fab (Digibind), or both may be necessary. In refractory cases of symptomatic digitalis toxicity that results in junctional tachycardia and causes severe symptoms, then intravenous phenytoin can be used. This should be administered in a monitored setting because of possible hypotension or the need for a pacemaker after resolution of the ectopic junctional rhythm.
Surgical Care
- If junctional rhythm is due to symptomatic sick sinus syndrome, permanent pacemaker implantation is indicated.
- If ectopic junctional tachycardia, which usually occurs in the pediatric population, is incessant and symptomatic, then radiofrequency ablation via a percutaneous approach is indicated.
Consultations
Symptomatic cases may benefit from a consultation with a cardiologist and/or an electrophysiologist to better define the etiology and approach to prevention.
Medication
The goals of pharmacotherapy are to reduce morbidity and prevent complications.
Anticholinergics
Agents used to accelerate heart rate if symptomatic bradycardia is present.
Atropine
Used to increase heart rate through vagolytic effects, causing an increase in cardiac output.
Adult
0.5-1 mg IV or ET q3-5min; not to exceed to 3 mg total (0.04 mg/kg)
Pediatric
0.02 mg/kg/dose IV; use a minimum of 0.1 mg
Coadministration with other anticholinergics have additive effects; pharmacologic effects of atenolol and digoxin may increase; antipsychotic effects of phenothiazines may decrease; tricyclic antidepressants with anticholinergic activity may increase effects
Documented hypersensitivity; thyrotoxicosis; narrow-angle glaucoma; tachycardia
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Caution in Down syndrome or children with brain damage to prevent hyperreactive response; caution in coronary heart disease, tachycardia, congestive heart failure, cardiac arrhythmias, hypertension, peritonitis, ulcerative colitis, hepatic disease, and hiatal hernia with reflux esophagitis; in prostatic hypertrophy, prostatism may result in dysuria and may require catheterization
Antidigitalis agents
Used to treat digitalis toxicity.
Digoxin immune Fab (Digibind)
Immunoglobulin fragment with a specific and high affinity for both digoxin and digitoxin molecules. Removes digoxin or digitoxin molecules from tissue binding sites.
Each vial of Digibind contains 40 mg of purified digoxin-specific antibody fragments, which bind approximately 0.6 mg of digoxin or digitoxin. Dose of antibody depends on total body load (TBL) of digoxin; estimates of TBL can be made in 3 ways, as follows:
(1) Estimate quantity of digoxin ingested in acute ingestion and assume 80% bioavailability (amount ingested [mg] X 0.8 = TBL).
(2) Obtain a serum digoxin concentration and, using a pharmacokinetics formula, incorporate the Vd of digoxin and the patient's body weight in kg (TBL = digoxin serum level [ng/mL] X 6 L/kg X body weight in kg).
(3) Use an empiric dose based on average requirements for an acute or chronic overdose in an adult or child.
If the quantity of ingestion cannot be estimated reliably, administer empirically (safest to use the largest calculated estimate); alternatively, be prepared to increase dosing if resolution is incomplete.
Adult
If amount ingested or serum level unknown, administer 10 vials IV for acute toxicity or 5 vials IV for chronic toxicity
If amount ingested or serum level known, dose can be calculated
Pediatric
Not established
None reported
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Caution in cardiac and renal failure; hypokalemia may occur following reversal of digoxin intoxication
Antiarrhythmic agents, Class 1-B
These agents alter the electrophysiologic mechanisms responsible for arrhythmia.
Phenytoin (Dilantin)
Depresses spontaneous depolarization in ventricular tissues.
Adult
15-20 mg/kg IV infusion, rate <50 mg/min
Pediatric
Administer as in adults
Amiodarone, benzodiazepines, chloramphenicol, cimetidine, fluconazole, isoniazid, metronidazole, miconazole, phenylbutazone, succinimides, sulfonamides, omeprazole, phenacemide, disulfiram, ethanol (acute ingestion), trimethoprim, and valproic acid may increase phenytoin toxicity; phenytoin effects may decrease when taken concurrently with barbiturates, diazoxide, ethanol (chronic ingestion), rifampin, antacids, charcoal, carbamazepine, theophylline, and sucralfate; phenytoin may decrease effects of acetaminophen, corticosteroids, dicumarol, disopyramide, doxycycline, estrogens, haloperidol, amiodarone, carbamazepine, cardiac glycosides, quinidine, theophylline, methadone, metyrapone, mexiletine, oral contraceptives, valproic acid
Documented hypersensitivity; sinoatrial block, second- and third-degree AV block, sinus bradycardia, or Adams-Stokes syndrome
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Perform blood counts and urinalyses when therapy is begun and at monthly intervals for several months thereafter to monitor for blood dyscrasias; discontinue use if a skin rash appears and do not resume use if rash is exfoliative, bullous, or purpuric; rapid IV infusion may result in death from cardiac arrest, marked by QRS widening; caution in acute intermittent porphyria and diabetes (may elevate blood sugars); discontinue use if hepatic dysfunction occurs
More on Junctional Rhythm |
| Overview: Junctional Rhythm |
| Differential Diagnoses & Workup: Junctional Rhythm |
 Treatment & Medication: Junctional Rhythm |
| Follow-up: Junctional Rhythm |
| Multimedia: Junctional Rhythm |
| References |
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References
Daubert JP, Rosero SZ, Corsello A. Tachycardias. In: Rakel RE, Bope ET, eds. Conn's Current Therapy. New York, NY: WB Saunders; 2001:286-95.
Deal BJ, Wolff GS, Gelband H. Current Concepts in Diagnosis and Management of Arrhythmias in Infants and Children. New York, NY: Futura Publishing; 1998:73-5.
Josephson ME. Clinical Cardiac Electrophysiology. 4th ed. Baltimore, Md: Williams & Wilkins; 2008.
Libby P, Bonow RO, Mann DL, Zipes, DP. Specific arrhythmias: diagnosis and treatment. In: Braunwald E, ed. Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Philadelphia, Pa: WB Saunders; 2007:640-5.
Further Reading
Keywords
junctional rhythm, accelerated junctional tachycardia, junctional bradycardia, tachycardia, atrioventricular block, AV block, bradycardia, sick sinus syndrome, sinus node dysfunction, heart block, complete heart block, digitalis toxicity, digoxin toxicity
