Sarah, a 35-year-old female, arrives at the emergency department with complaints of palpitations and lightheadedness. She describes a sudden onset of palpitations, which have been recurring over the past 30 minutes. She denies any chest pain, shortness of breath, or syncope. Her vital signs are stable, with a heart rate of 80 beats per minute, blood pressure of 120/80 mmHg, and normal respiratory rate. On examination, there are no significant findings, and her cardiovascular exam is unremarkable. Describe the electrocardiogram (ECG) characteristics you would expect to find in a patient with premature junctional complexes (PJCs).