What condition is characterized by rapid atrial waves that prevent the AV node from responding effectively?

Atrial flutter is characterized by a rapid and organized rhythm where the atria contract at a very high rate, typically around 240 to 340 beats per minute. This condition is characterized by the presence of "sawtooth" waves, known as F-waves, seen on an electrocardiogram (ECG). Due to the high frequency of atrial contractions, the atrioventricular (AV) node becomes overwhelmed and is unable to respond effectively to every impulse, which leads to a variable or rapid ventricular response.

In contrast, atrial fibrillation, while also involving rapid atrial waves, is much more chaotic and disorganized than atrial flutter. It results in an irregularly irregular rhythm without distinct F-waves. Ventricular tachycardia pertains to the ventricles and is a different type of arrhythmia that does not involve the atria directly in the manner that atrial flutter does. Myocardial ischemia refers to a lack of blood flow to the heart muscle and does not specifically describe the rapid atrial activity that is the hallmark of atrial flutter.

Thus, the defining feature of atrial flutter is the rapid and organized atrial electrical activity that results in ineffective conduction through the AV node.