Which arrhythmia is characterized by a wide QRS complex and a regular rhythm?

Ventricular tachycardia is characterized by a wide QRS complex and a regular rhythm due to the abnormal electrical activity originating from the ventricles. This arrhythmia occurs when there is a rapid succession of ventricular depolarizations, which leads to the widening of the QRS complexes on the electrocardiogram (ECG). The regular rhythm indicates that the beats occur at a consistent interval, which is a distinct feature of ventricular tachycardia.

In contrast, other arrhythmias mentioned do not fit these criteria. Atrial flutter typically presents with a "sawtooth" pattern in the atrial activity with a narrow QRS complex. Bradycardia denotes a slow heart rate and does not specifically indicate a wide QRS complex. Supraventricular tachycardia generally results in a narrow QRS complex as well since it originates above the ventricles. Therefore, the defining features of a wide QRS complex and a regular rhythm make ventricular tachycardia the correct answer.