case_images: PMC11787247_01
case_images: The initial ECG of a 13-year-old asymptomatic patient with an irregular rhythm. Wide QRS complexes were thought to be secondary to DVR with aberration, premature junctional beats with aberration, or premature ventricular complexes. Narrow QRS complexes were thought to be secondary to DVR conducted normally versus premature junctional beats
case_images: 246_2024_3506_Fig1_HTML.jpg
case_images: PMC11787247_01_246_2024_3506_Fig1_HTML.jpg
case_images: Fig1
case_images: Initial ECG demonstrated multiple relatively narrow premature QRS complexes of different morphologies (Fig. 1).
case_images: ECG during exercise test noting premature beats with narrow QRS complexes that were identical to the conducted beats without preceding atrial activity and did not disturb the atrial mechanism. There were also frequent premature beats with wide QRS complexes of varying morphology
case_images: 246_2024_3506_Fig2_HTML.jpg
case_images: PMC11787247_01_246_2024_3506_Fig2_HTML.jpg
case_images: Fig2
case_images: This was remarkable for premature beats with premature narrow QRS complexes prior to exercise that were identical to the conducted beats without preceding atrial activity and did not disturb the atrial mechanism (Fig. 2).
case_images: EP Study: Frequent 1:2 conduction was demonstrated. Here, an episode of 1:2 response with aberrant conduction is noted with prolonged HV interval on the aberrant beat
case_images: 246_2024_3506_Fig3_HTML.jpg
case_images: PMC11787247_01_246_2024_3506_Fig3_HTML.jpg
case_images: Fig3
case_images: Given the suspicion that DVR with frequent aberrant conduction was the underlying etiology of ventricular dysfunction, a comprehensive electrophysiology study (EPS) was performed (Fig. 3).