Atrioventricular Dissociation (Treatment)
The important considerations and steps in the treatment of patients with AV dissociation include the hemodynamic status of the patient and recognition of the underlying pathology.
For patients who are hemodynamically unstable, i.e., patients with ventricular tachycardia, the initial treatment of choice is direct-current cardioversion or intravenous drug therapy, depending on the stability of the patient.
Ascertaining if AV conduction is intact is important in patients with AV dissociation due to an accelerated junctional rhythm following cardiac surgery.
Rarely, patients have complete AV block with an accelerated focus distal to the level of block; when the accelerated focus becomes quiescent, heart block is present.
Consultations Patients with unexplained or uncorrected persistent symptomatic AV dissociation due to an escape rhythm or ventricular tachycardia may require referral to an electrophysiologist or a cardiologist.
Anticholinergic agents Competitive inhibitor at autonomic, postganglionic, and cholinergic receptors.
Atropine Sulfate Increases heart rate through vagolytic effects, causing increase in cardiac output.
Adult 0.5-1.0 mg IV or ET q3-5min; not to exceed 3 mg total (0.04 mg/kg) Pediatric 0.02 mg/kg/dose IV; minimum of 0.1 mg Other anticholinergics have additive effects; may increase pharmacologic effects of atenolol and digoxin; may decrease antipsychotic effects of phenothiazines; tricyclic antidepressants with anticholinergic activity may increase effects Documented hypersensitivity; thyrotoxicosis; narrow-angle glaucoma; tachycardia Pregnancy C - Safety for use during pregnancy has not been established.
Precautions Avoid in Down syndrome and/or children with brain damage to prevent hyperreactive response; avoid in coronary heart disease, tachycardia, congestive heart failure, cardiac arrhythmias, and hypertension; caution in peritonitis, ulcerative colitis, hepatic disease, and hiatal hernia with reflux esophagitis; in patients with prostatic hypertrophy, prostatism is associated with dysuria and may require catheterization Adrenergic agonist agents Stimulate myocardial performance and improve coronary artery blood flow.
Binds beta-receptors of heart, smooth muscle of bronchi, skeletal muscle, vasculature, and alimentary tract.
Adult Dilute 1 mL of 1:5000 solution (0.2 mg) with 10 mL saline solution or D5W for injection Dose: 2-6 mcg/min IV (1-3 mL of diluted solution) Alternatively, dilute 10 mL of 1:5000 solution (2 mg) in 500 mL of D5W or dilute 5 mL of 1:5000 solution (1 mg) in 250 mL of D5W and administer 5 mcg/min (1.25 mL/min of diluted solution) to achieve heart rate of 90-100 bpm Pediatric Not established Tricyclic antidepressants may potentiate pressor response of direct-acting vasopressors Documented hypersensitivity; tachyarrhythmias, tachycardia, or heart block caused by digitalis intoxication; ventricular arrhythmias that require inotropic therapy; angina pectoris Pregnancy C - Safety for use during pregnancy has not been established.