Final answer:
Adenosine affects atrial tachycardia by increasing parasympathetic stimulation, which can slow down the heart rate and potentially terminate the rapid, abnormal heart rhythm by extending the refractory period of the atrioventricular node.
Step-by-step explanation:
The student asked, How does adenosine affect atrial tachycardia? Adenosine plays a significant role in heart function and can influence atrial tachycardia. During atrial tachycardia, the heart's atrial chambers may beat very quickly. The body's autonomic nervous system controls the heart rate through two types of stimulation: sympathetic and parasympathetic. While the sympathetic nervous system works to increase heart rate and is a positive inotrope, the parasympathetic nervous system decreases the heart rate and is a negative inotrope.
Adenosine is a substance in the body that can increase blood flow via vasodilation and also has a direct cardiovascular effect by activating the parasympathetic nervous system. When adenosine is administered, it increases the parasympathetic stimulation, decreasing the release of ACh which allows the heart rate to increase up to approximately 100 bpm. In the context of atrial tachycardia, administration of adenosine can slow down the heart rate by acting on the atrioventricular node and prolonging its refractory period, therefore normalizing the heart rhythm and potentially terminating the tachycardia.