What initial drug might be used for a patient with third-degree AV block and low blood pressure?

The use of a dopamine infusion in the case of third-degree AV block accompanied by low blood pressure is a clinically sound choice. Dopamine acts as both an inotropic agent and a vasopressor, depending on the dose administered. In this scenario, when a patient presents with a complete heart block and also exhibits hypotension, it’s essential to stabilize the patient’s hemodynamics.

Dopamine can increase cardiac output by enhancing myocardial contractility, which is vital when the heart's conduction pathway is disrupted, as seen in third-degree AV block. Moreover, at the right dosing range, dopamine can help increase systemic vascular resistance, further supporting blood pressure levels.

Other medications such as adrenaline (epinephrine), while also effective in certain emergency situations, are generally considered for more acute life-threatening arrhythmias or in cases of cardiac arrest. Amiodarone is primarily used for ventricular or atrial fibrillation and does not directly address the hypotension associated with third-degree AV block. Furosemide is a diuretic meant for fluid management and does not have a role in the acute management of AV block and hypotension.

In summary, the selection of a dopamine infusion as an initial therapeutic approach reflects its capability to effectively manage the