Final answer:
As the patient is asymptomatic and has stable blood pressure, the recommended action is to observe and monitor. Other options like adenosine, cardioversion, or amiodarone are typically used in more acute or symptomatic cases.
Step-by-step explanation:
In this scenario, the patient presents with a rapid irregular wide complex tachycardia, with a ventricular rate of 138 beats per minute and a history of angina but is currently asymptomatic with a stable blood pressure (BP) of 110/70. Considering the patient's stable condition, the recommended action is to observe and monitor the patient. Administering adenosine is primarily considered in cases of supraventricular tachycardia (SVT) to aid in diagnosis or to restore normal rhythm. Performing synchronized cardioversion is more appropriate for symptomatic patients or those with hemodynamic instability. Administering amiodarone may be considered for ventricular tachycardia or fibrillation, mainly in unstable patients or those who do not respond to other treatments. In this case, immediate invasive interventions are not necessary, and careful observation with continuous cardiac monitoring is prudent.