From the Guidelines
AV nodal blocking agents are medications that slow conduction through the atrioventricular (AV) node of the heart, and the primary agents include beta-blockers, non-dihydropyridine calcium channel blockers, and digoxin, as stated in the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1. These medications are commonly used to treat supraventricular tachycardias, atrial fibrillation, and atrial flutter by slowing ventricular response rates.
- The non-dihydropyridine calcium channel blockers, such as verapamil and diltiazem, are effective in converting PSVT to normal sinus rhythm, with verapamil given as a 2.5 mg to 5 mg IV bolus over 2 minutes, and diltiazem given as a 15 mg to 20 mg IV dose over 2 minutes 1.
- Beta-blockers, such as metoprolol, atenolol, and propranolol, are also used to treat supraventricular tachyarrhythmias by antagonizing sympathetic tone in nodal tissue, resulting in slowing of conduction 1.
- It is essential to exercise caution when using AV nodal blocking agents, particularly in patients with pre-excited atrial fibrillation or flutter, as these medications can accelerate the ventricular response, and in patients with obstructive pulmonary disease or congestive heart failure, as they can exacerbate these conditions 1. The choice of AV nodal blocking agent depends on the specific clinical scenario, and the dosing regimens should be carefully followed to minimize adverse effects.
- For example, verapamil should not be given to patients with wide-complex tachycardias or impaired ventricular function, and beta-blockers should be used with caution in patients with obstructive pulmonary disease or congestive heart failure 1.
From the FDA Drug Label
Adenosine injection exerts a direct depressant effect on the SA and AV nodes and may cause first-, second- or third-degree AV block, or sinus bradycardia. An atrioventricular (AV) nodal blocking agent is a drug that blocks or slows the electrical conduction between the atria and ventricles in the heart, which can cause:
- First-, second-, or third-degree AV block
- Sinus bradycardia Examples of AV nodal blocking agents include:
- Verapamil
- Adenosine 2 3
From the Research
Definition of Atrioventricular (AV) Nodal Blocking Agents
Atrioventricular (AV) nodal blocking agents are a class of drugs that slow the conduction of electrical impulses through the atrioventricular node, which is a critical part of the heart's electrical conduction system.
Examples of AV Nodal Blocking Agents
- Beta-adrenergic blockers (e.g., metoprolol, esmolol) 4, 5, 6, 7
- Non-dihydropyridine calcium channel blockers (e.g., verapamil, diltiazem) 4, 5, 7, 8
- Digoxin 4, 5
Mechanism of Action
These agents work by affecting the conduction of electrical impulses through the atrioventricular node, thereby controlling the ventricular rate in conditions such as atrial fibrillation and atrial flutter 4, 5, 6.
Clinical Uses
AV nodal blocking agents are used to: