Final answer:
The first-line drug for symptomatic bradycardia in the absence of reversible causes is Epinephrine.
Explanation:
Epinephrine is the first-line drug given for symptomatic bradycardia in the absence of immediately reversible causes. It acts on the a- and ß-adrenergic receptors to increase heart rate and improve cardiac function. Bradycardia is defined as a resting heart rate below 60 bpm and may present symptoms like weakness, fatigue, dizziness, or chest discomfort.
Learn more about Bradycardia and Epinephrine here:
https://brainly.com/question/47647940
