When analyzing disturbances originating from the atria and ventricles, which of the following statements is correct about their QRS complex?

The QRS complex represents ventricular depolarization and is a key component in analyzing the electrical activity of the heart. In the context of disturbances originating from the atria, these typically affect the electrical impulse before it reaches the ventricles. Since the normal conduction pathway through the atrioventricular node leads to a standardized and narrow QRS complex, disturbances arising from the atria generally do not modify the conduction through the ventricles. Therefore, atrial disturbances are characterized by a narrow QRS complex.

This is in contrast to ventricular disturbances, which can be associated with wider QRS complexes due to altered conduction patterns. Conditions like bundle branch blocks, ventricular tachycardia, or other intraventricular conduction delays cause the ventricles to depolarize more slowly, resulting in a wider QRS complex.

Thus, the correct statement about atrial disturbances is that they indeed have a narrow QRS complex, reflecting the normal conduction of electrical impulses through the ventricles without significant alteration from atrial issues.