Final answer:
To differentiate between accelerated idioventricular rhythm and junctional rhythm on an ECG, look for a widened QRS complex and a ventricular rate of 50-110 bpm in accelerated idioventricular rhythm, as opposed to a junctional rhythm which has a narrow QRS and a rate of 40-60 bpm, along with absent or inverted P waves.
Step-by-step explanation:
The electrocardiogram (ECG) findings that differentiate accelerated idioventricular rhythm from junctional rhythm involve the observation of the shape and rate of the QRS complex. Accelerated idioventricular rhythm typically shows a widened QRS complex with a ventricular rate that is faster than the normal idioventricular rate but slower than ventricular tachycardia (typically 50-110 beats per minute). Conversely, a junctional rhythm can be identified by a narrow QRS complex with absent or inverted P waves, occurring at a rate of 40-60 beats per minute when it arises from the atrioventricular (AV) junction. Additional diagnostic tools such as ECG lead analysis and comparison to previous ECGs may provide further clarity in distinguishing these rhythms, particularly given the individual variations in heart shape, size, and orientation which affect ECG presentations.