In patients with<unk>  onset AV block,reversible causes such as drug toxicity,thyroid dysfunction, Lyme disease, etc should be taken into consideration. A decision should then be made regarding usage of [medical]] therapy or other treatment modalities such as temporary pacing.
2. In selected patients with symptomatic second-degree or third-degree atrioventricular block who are on chronic stable doses of medically necessary antiarrhythmic or betablocker therapy, it is reasonable to proceed to permanent pacing without further observation for drug washout or reversibility. (Level of Evidence: B-NR)
3. In patients with second-degree or third degree atrioventricular block associated with cardiac sarcoidosis, permanent pacing, with additional defibrillator capability if needed and meaningful survival of greater than 1 year is expected, without further observation for reversibility is reasonable. (Level of Evidence: B-NR)
4. In patients with symptomatic second degree or third-degree atrioventricular block associated with thyroid function abnormalities but without clinical myxedema, permanent pacing without further observation for reversibility may be considered. (Level of Evidence: C-LD)"
2. For patients with second-degree or thirddegree atrioventricular block associated with symptoms or hemodynamic compromise and who have low likelihood for coronary ischemia, beta-adrenergic agonists, such as isoproterenol, dopamine, dobutamine, or epinephrine, may be considered to improve atrioventricular conduction, increase ventricular rate, and improve symptoms.(Level of Evidence: B-NR)
3.For patients with second-degree or thirddegree atrioventricular block associated with symptoms or hemodynamic compromise in the setting of<unk>  inferior MI, intravenous
aminophylline may be considered to improve atrioventricular conduction, increase ventricular rate, and improve symptoms. (Level of Evidence: C-LD) "
The<unk>  treatment of bradycardia attributable to atrioventricular block will often begin with timely identification and removal of potential causative factors as well as medical therapy.
Atropine is a parasympatholytic drug that has a short duration of action, is easy to administer and has relatively low risk of adverse reactions (except for obvious antimuscarinic actions).
It is effect for blocks at the level of the AV node and bradycardia secondary to increased vagal tone. It should be used judiciously in patients with AV blocks at the His-Purkinje or His bundle level as it may worsen the patients condition. 
Beta-adrenergic agonists such as isoproterenol, dopamine, dobutamine, and epinephrine exert direct effects to enhance atrioventricular nodal and His-Purkinje conduction.
Adverse effects of beta-adrenergic agonists may include ventricular arrhythmias, excacerbation of coronary ischemia and hypotension. 
Aminophylline is a nonselective adenosine receptor antagonist and phosphodiesterase inhibitor.
It is used clinically as a bronchodilator and as a reversal drug for dipyridamole, adenosine, and regadenoson in pharmacologic nuclear stress testing.
It has a possible role in the treatment of AV block but sparse literature is available regarding this.
Paroxysmal AV block Acute Management
Paroxysmal AV block Treatment for Reflex Syncope
Wide complex tachycardia medical therapy
Pulseless ventricular tachycardia medical therapy
Paroxysmal AV block Cardiac Pacing
Paroxysmal AV block Initial Approach
Third degree AV block MRI
Third degree AV block CT scan