Which drug classes are listed as capable of causing tachycardia during anesthesia?

Which drug classes are listed as capable of causing tachycardia during anesthesia?

• A. Anticholinergics
• B. Dissociatives
• C. Catecholamines
• D. All of the above

Answer: (D)

Tachycardia during anesthesia can result from drugs that either remove parasympathetic braking, stimulate the sympathetic system, or directly increase adrenergic drive. Anticholinergics like atropine or glycopyrrolate block muscarinic receptors, removing vagal influence on the heart and allowing the sinoatrial node to fire faster. Dissociatives such as ketamine provoke sympathetic activation, increasing endogenous catecholamine release and beta-adrenergic stimulation, which raises heart rate. Catecholamines used as vasopressors or inotropes (like epinephrine, norepinephrine, or dopamine) directly stimulate beta-1 receptors in the heart, increasing heart rate and contractility. Since each class can cause tachycardia on their own, all of the above are capable of producing this effect.

Tachycardia during anesthesia can result from drugs that either remove parasympathetic braking, stimulate the sympathetic system, or directly increase adrenergic drive.

Anticholinergics like atropine or glycopyrrolate block muscarinic receptors, removing vagal influence on the heart and allowing the sinoatrial node to fire faster.

Dissociatives such as ketamine provoke sympathetic activation, increasing endogenous catecholamine release and beta-adrenergic stimulation, which raises heart rate.

Catecholamines used as vasopressors or inotropes (like epinephrine, norepinephrine, or dopamine) directly stimulate beta-1 receptors in the heart, increasing heart rate and contractility.

Since each class can cause tachycardia on their own, all of the above are capable of producing this effect.