What drugs may be used as second-line therapy for a patient with bradyarrhythmia and signs of hemodynamic compromise?

The use of epinephrine or dopamine as second-line therapy in cases of bradyarrhythmia with hemodynamic compromise is based on their pharmacological effects that can significantly support cardiac function. Both epinephrine and dopamine act as sympathomimetic agents that can increase heart rate and improve cardiac output, which is critical when a patient exhibits signs of hemodynamic instability due to bradyarrhythmia.

Epinephrine, at higher doses, can stimulate beta-adrenergic receptors in the heart, resulting in increased heart rate (positive chronotropic effect) and improved myocardial contractility (positive inotropic effect). Dopamine, particularly at moderate doses, can also enhance cardiac output by stimulating beta receptors and improving blood flow.

In contrast, other options such as aspirin or nitroglycerin are generally used for different indications, such as myocardial infarction or angina management, rather than directly addressing bradycardia. Amiodarone and adenosine are primarily utilized for treating tachyarrhythmias rather than bradyarrhythmias, while atropine is often considered a first-line medication for symptomatic bradycardia. Sodium bicarbonate is not indicated in the management of bradyarrhythmia and is typically used for metabolic