What cardiac condition is characterized by a splintered QRS complex?

The cardiac condition characterized by a splintered QRS complex is tachycardia dysplasia. This condition refers to an abnormality in the structural organization of the heart that can lead to ventricular tachycardia and is associated with interstitial fibrosis and other pathological changes, which can result in conduction delays or aberrations that lead to a splintered appearance of the QRS complex on an electrocardiogram (ECG).

In contrast, right and left bundle branch blocks typically present with distinct QRS morphology changes that are more uniform rather than splintered. Atrial fibrillation involves an irregularly irregular rhythm and does not typically lead to a splintering of the QRS complexes, as it primarily affects atrial contraction rather than the ventricular conduction system. Therefore, the unique nature of the splintered QRS complex is quite indicative of tachycardia dysplasia, which is the reason this answer is correct.