What are atrial flutter and atrial fibrillation classified as?

Atrial flutter and atrial fibrillation are classified as supraventricular arrhythmias because they originate in the atria of the heart. Supraventricular arrhythmias specifically involve abnormal electrical impulses that affect the upper chambers of the heart – the atria – and lead to irregular heartbeats.

In atrial flutter, there is a reentrant circuit in the right atrium that causes rapid atrial depolarizations, resulting in a characteristic "sawtooth" pattern on an electrocardiogram. Atrial fibrillation, on the other hand, involves chaotic electrical activity in the atria that leads to a rapid and irregular heartbeat.

This classification is important because it helps in understanding the underlying mechanisms of these arrhythmias and aids in determining appropriate treatment options. Other choices such as ventricular arrhythmias involve the lower chambers of the heart, cardiac myopathies refer to diseases of the heart muscle, and heart valve disorders pertain to issues with the heart’s valves, none of which accurately describe the nature of atrial flutter and atrial fibrillation.