What is the primary treatment for symptomatic bradycardia?

The primary treatment for symptomatic bradycardia is atropine. Atropine works by blocking the effects of the vagus nerve on the heart, which leads to an increase in heart rate. It is particularly effective when bradycardia is due to increased vagal tone, such as in cases of AV block or certain types of heart rhythm disturbances. By inhibiting acetylcholine at the muscarinic receptors, atropine reduces parasympathetic tone and can stabilize the heart rhythm, making it a first-line option in emergent situations of symptomatic bradycardia.

Other medications listed, such as isoproterenol, beta-blockers, and amiodarone, serve different roles or are used in specific situations that are distinct from the standard treatment of symptomatic bradycardia. Isoproterenol may be considered in cases of severe bradycardia unresponsive to atropine, but it is generally not the first choice due to its broad effects on heart rate and potential to increase myocardial oxygen demand. Beta-blockers are typically used to manage tachycardia or heart rate control in other contexts and can exacerbate bradycardia. Amiodarone is primarily an antiarrhythmic and may be indicated for